Hydraulics of subaqueous ash flows as deduced from their deposits

Science.gov (United States)

Doronzo, Domenico M.; Dellino, Pierfrancesco

2012-09-01

Subaqueous ash flows are gravity currents consisting of a mixture of sea water and ash particles. Also called volcaniclastic turbidity currents (VTCs), they can be generated because of remobilization of pyroclastic fall deposits, which are emplaced into the sea around a volcanic island, as well as far away, during an explosive eruption. The VTC upper part is the turbulent transport system for the flow, whereas the viscous basal one is the depositional system. Typical sequences of VTC deposits are characterized by cross-laminations, planar and convolute laminations, and massive beds, which reflect the stratified nature of the flow. Here, the analysis of some VTC hydraulic parameters is presented in order to depict flow behavior and sedimentation during deposition. A reverse engineering approach is proposed, which consists of calculating hydraulic parameters by starting from deposit features. The calculated values show that a VTC is homogeneously-turbulent for most of the thickness, but is viscous at its base. First, cross-laminations are directly acquired over the rough pre-existing seafloor, then planar or convolute laminations aggrade over the newly formed substrate. Finally, fine-grained suspended particles gently settle and cap the flow deposit.

Sequential development of tidal ravinement surfaces in macro- to hypertidal estuaries with high volcaniclastic input: the Miocene Puerto Madryn Formation (Patagonia, Argentina)

Science.gov (United States)

Scasso, Roberto A.; Cuitiño, José I.

2017-08-01

The late Miocene beds of the Puerto Madryn Formation (Provincia del Chubut, Argentina) are formed by shallow marine and estuarine sediments. The latter include several tidal-channel infills well exposed on the cliffy coast of the Peninsula Valdés. The Bahía Punta Fósil and Cerro Olazábal paleochannels are end members of these tidal channels and show a fining-upward infilling starting with intraformational channel lag conglomerates above deeply erosional surfaces interpreted as fluvial ravinement surfaces (the erosion surface formed in the purely fluvial or the fluvially dominated part of the estuary, where erosion is driven by fluvial processes). These are overlain and eventually truncated (and suppressed) by the tidal ravinement surface (TRS), in turn covered with high-energy, bioclastic conglomerates mostly formed in the "tidally dominated/fluvially influenced" part of an estuary. Above, large straight or arcuate point bars with alternatively sandy/muddy seasonal beds and varying trace and body fossil contents were deposited from the freshwater fluvially dominated to saline-water tidally dominated part of the estuary. The upper channel infill is formed by cross-bedded sands with mud drapes and seaward-directed paleocurrents, together with barren, volcaniclastic sandy to muddy heterolithic seasonal rhythmites, both deposited in the fluvially dominated part of the estuary. Volcanic ash driven by the rivers after large explosive volcanic eruptions on land resulted in sedimentation rates as high as 0.9 m per year, preserving (through burial) the morphology of tidal channels and TRSs. The channel deposits were formed in a tide-dominated, macrotidal to hypertidal open estuary with well-developed TRSs resulting from strong tidal currents deeply scouring into the transgressive filling of the channels and eventually cutting the fluvial ravinement surface. The TRSs extended upstream to the inner part of the estuary during long periods of low sedimentation rates

Characterization of Tar Deposits, Extraction and Sorption Properties

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Pryszcz Adrian

2016-06-01

Full Text Available The main goal of this paper was to characterize and find a useful solution for the decomposition of tar deposits. For the experimental part, tar deposits, formed by polymerization and condensation reactions, were chosen from a storage tank for tars. At first the initial analyses of tar deposits (elemental, thermogravimetric, and calorimetric analyses were performed. After the characterization, the tar deposits were extracted in the Soxhlet extractor by acetone, toluene, and quinolone and activated with potassium hydroxide. As the final step of this work, the sorption characterization on the 3Flex Surface Characterization Analyzer (Micromeritics was performed. The specific surface area of the samples was evaluated using two methods - a single point measurement at p/p0=0.2 and BET method. Micropore and external surface areas were calculated based on a t-plot analysis (carbon black model.

Regional distribution of volcaniclastic layer and its implication for segmentation of the Nankai seismogenic zone

Science.gov (United States)

Sasaki, T.; Lim, J.; Higashi, M.; Park, J.

2010-12-01

The Nankai Trough is known as one of the best-suited convergent plate margins for studying accretionary prism growth as well as subduction zone earthquakes. Along the Nankai accretionary margin off southwest Japan, the Shikoku Basin which formed 26-15 Ma as backarc spreading in the Philippine Sea Plate is being subducted about 4 cm/year to the northwest. The Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) penetrated the Nankai accretionary prism and the incoming sedimentary section along the Ashizuri and Muroto transects, off Shikoku Island. Also, Integrated Ocean Drilling Program (IODP), which represented just one part of a multi-stage project known as the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) has been conducting drilling cruises now. IODP Expedition 322 in 2009, the coring was carried out at two drilling sites on the northern part of the Shikoku Basin in the subducting Philippine Sea plate. One of the major achievements of Expedition 322 is a discovery of late Miocene (10.2-7.6 Ma) tuffaceous and volcaniclastic sandstone layer (Underwood et al., IODP Prel. Rept. 322, 2009) that has not been previously recognized in the Nankai Trough. Based on age and volcanic sand content analysis, these volcaniclastic layers were unique to the Shikoku Basin off Kii Peninsula. The closest source of this volcanic layer was supposed to be the Izu-Bonin arc. Subducted sediments ultimately affect subduction zone geochemistry, thermal structure, and seismogenesis. High porosity of the volcaniclastic sandstone layer suggests the transportation of fluid to the subduction zone, it might affect the initiation and evolution of the decollement zone or plate boundary fault in the Nankai Trough. We interpreted single channel and multichannel seismic reflection profiles that have been acquired in the Nankai Trough margin by Japan Agency for Marine-Earth Science and Technology (JAMSTEC) since the year of 1997. We tried to map the major seismic layers such as

An approach of understanding acid volcanics and tuffaceous volcaniclastics from field studies: A case from Tadpatri Formation, Proterozoic Cuddapah basin, Andhra Pradesh, India

Science.gov (United States)

Goswami, Sukanta; Upadhyay, P. K.; Bhagat, Sangeeta; Zakaulla, Syed; Bhatt, A. K.; Natarajan, V.; Dey, Sukanta

2018-03-01

The lower stratigraphic part of the Cuddapah basin is marked by mafic and felsic volcanism. Tadpatri Formation consists of a greater variety of rock types due to bimodal volcanism in the upper part. Presence of bimodal volcanism is an indication of continental rift setting. Various genetic processes involved in the formation of such volcanic sequence result in original textures which are classified into volcaniclastic and coherent categories. Detailed and systematic field works in Tadpatri-Tonduru transect of SW Cuddapah basin have provided information on the physical processes producing this diversity of rock types. Felsic volcanism is manifested here with features as finger print of past rhyolite-dacite eruptions. Acid volcanics, tuffs and associated shale of Tadpatri Formation are studied and mapped in the field. With supporting subordinate studies on geochemistry, mineralogy and petrogenesis of the volcanics to validate field features accurately, it is understood that volcanism was associated with rifting and shallow marine environmental condition. Four facies (i.e., surge, flow, fall and resedimented volcaniclastic) are demarcated to describe stratigraphic units and volcanic history of the mapped area. The present contribution focuses on the fundamental characterization and categorization of field-based features diagnostic of silica-rich volcanic activities in the Tadpatri Formation.

Structural characterization of MAPLE deposited lipase biofilm

Energy Technology Data Exchange (ETDEWEB)

Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

2014-11-30

Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

Geology of the Sierra de los ajos (Laguna Merin basin, Rocha, Uruguay)

International Nuclear Information System (INIS)

Morales, E.; Muzio, R.; Veroslavsky, G.

2006-01-01

The studied area is located between Lascano city and Sierra de los Ajos hills (department of Rocha, East Uruguay). It is represented by volcanic deposits correspondent to Puerto Gómez and Arequita Formations which are exposed as remarkable and preserved hills in areas recovered by Cenozoic sediments and wetlands. Detailed geological mapping allowed the descriptive characterization of eight volcanic facies: five coherent facies and three volcaniclastic facies. Several structural lineaments located in a constrictive framework, according to the transcurrent system represented by the northeastern portion of the Santa Lucía - Aiguá - Merín tectonic corridor (SaLAM), were identified. These lineaments (Bella Vista, India Muerta and Los Ajos) controlled the tecto-magmatic arrange in this portion of the basin, determining petrographic and structural differences in the area. Particularly, to the East of the India Muerta with structural trend Nº20 felsic lavas corrrespondent to the Sierra de los Ajos and related volcaniclastic deposits are present. On the other hand to the West, intermediate to felsic lavas occurred and no volcaniclastic deposits have been yet identified

Early Depositional History of the Eocene Izu-Bonin Mariana Arc, Western Pacific Ocean

Science.gov (United States)

Waldman, R.; Marsaglia, K. M.; Tepley, F. J., III

2015-12-01

Expedition 351 of the International Ocean Discovery Program cored an Eocene section at Site U1438 in the Philippine Sea that provides insight into the early history of the Izu-Bonin arc. Subduction here is hypothesized to have initiated spontaneously, leaving a characteristic depositional sequence of post-subduction-initiation localized extension and volcanism. We conducted detailed macroscopic and microscopic study of the cores of the lowermost 100m of volcaniclastic and sedimentary rocks (Unit IV) directly overlying subduction initiation igneous basement, to identify depositional facies and trends. We subdivided Unit IV into three subunits based on lithologic characteristics. Transitions between the subunits are relatively abrupt, occurring within the length of a single core. The lowermost subunit (IVA) consists of 4 meters of laminated pelagic claystone with thin beds of graded volcaniclastic siltstone, and fine-grained tuff laminae composed of plagioclase feldspar and green-brown amphibole. The middle subunit (IVB) comprises 51 meters of texturally variable, thick-bedded, coarse-grained gravity flow deposits. These are composed of volcaniclastic sandstone and conglomerate containing glassy and tachylitic volcanic grains as well as sedimentary lithic fragments, along with traces of shallow-water carbonate bioclasts. Subunit IVB sediments are poorer in feldspar than IVA and contain only trace amphibole. They show variable grain rounding and an upsection increase in vitric components. Tachylite grains range from sub-angular to well rounded throughout, and other volcanic grain types show upward increases in angularity and vesicularity. The abrupt transition from pelagic sediments in subunit IVA to shallow-water-sourced gravity flows in subunit IVB suggests a rapid emergence of shallow-water to subaerial volcanic center early in the arc's development. The upper part of subunit IVB also contains igneous intrusions, providing possible evidence for more proximal

The first evidence of trace fossils and pseudo-fossils in the continental interlava volcaniclastic sediments on the Faroe Islands

Czech Academy of Sciences Publication Activity Database

Pokorný, R.; Krmíček, Lukáš; Árting, U. E.

2015-01-01

Roč. 63, č. 1 (2015), s. 45-57 ISSN 2245-7070 Institutional support: RVO:67985831 Keywords : Faroe Islands * trace fossils * pseudo- fossils * volcaniclastic sediments Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.889, year: 2015 http://2dgf.dk/xpdf/bull63-45-57.pdf

The origin of volcanic rock fragments in Upper Pliocene Grad Member of the Mura Formation, North-Eastern Slovenia

Directory of Open Access Journals (Sweden)

Polona Kralj

2006-12-01

Full Text Available Fresh-water, coarse-grained and detritus-dominated Mura Formation in North Eastern Slovenia includes pyroclastic and volcaniclastic deposits originating from Upper Pliocene volcanic activity of basaltic geochemical character. Although localized in occurrence at the hamlet Grad, these pyroclastic and volcaniclastic sediments forma distinctive depositional unit, for which the term “Grad Member” is proposed and introduced in this paper.In the Grad area no lavas or cinder cones are preserved, and the origin of volcaniclastic fragments still uncertain. For this reason, chemical composition of basaltic rock fragments from the Grad Member volcaniclastics has been studied and compared with basaltic rocks from the neighboring locations at Klöch, Kindsberg, Dölling and Neuhaus. The Grad Member pyroclastic and volcaniclastic deposits seem to be fed from the same source which is different from the occurrences in Austria. That supports the idea about the existence of a local volcanic centre in the present Grad area. The old volcanic edificeswerepossiblydestroyed by the late-stage hydrovolcanic eruptions, and pyroclastic and volcaniclastic deposits subjected to constant reworking by fluvial currents in a dynamic sedimentary environment of alluvial fan and braided river systems.

Fluid typing and tortuosity analysis with NMR-DE techniques in volcaniclastic reservoirs, Patagonia/Argentina

Energy Technology Data Exchange (ETDEWEB)

Bustos, Ulises Daniel [Schlumberger Argentina S.A., Buenos Aires (Argentina); Breda, Eduardo Walter [Repsol YPF Comodoro Rivadavia, Chubut (Argentina)

2004-07-01

Alternative hydrocarbon-detection techniques are used to differentiate water from hydrocarbon where resistivity-based methods are difficult to apply, such as freshwater reservoirs and complex lithologies. One of these areas is represented by the complex volcaniclastic freshwater reservoirs in the Golfo San Jorge basin, Patagonia Argentina, where water and oil have often identical response on conventional logs. Some advances in hydrocarbon identification based on nuclear magnetic resonance (NMR) techniques were achieved in long T1 environments (very light oils, gas) in the Golfo San Jorge basin by previous NMR fluid typing methods. However, since medium to heavy oils are commonly present in these intervals, hydrocarbon detection by such techniques cannot be properly achieved. In addition, restricted diffusion phenomena recognized in these intervals, constitute further complications in fluid typing since its presence have similar response than native oil. To address this problem, a fluid characterization method using NMR Diffusion-Editing techniques and processing/interpretation with D-T2 maps in a suite of NMR measurements was applied. The technique allowed the detection and evaluation of restricted diffusion in these reservoirs, enabling better hydrocarbon characterization in a broad viscosity range (from light to heavy). The method also improved the petrophysical evaluation because restricted diffusion is related to tortuosity in the reservoir. Since the application of this innovative reservoir evaluation method, fluid prognosis vs well completion results was increased from around 68% to around 88% in Golfo San Jorge basin. Moreover, in some of these areas rates above 95% were recently achieved in 2004. (author)

Preparation and characterization of thick metastable sputter deposits

International Nuclear Information System (INIS)

Allen, R.P.; Dahlgren, S.D.; Merz, M.D.

1975-01-01

High-rate dc supported-discharge sputtering techniques were developed and used to prepare 0.1 mm to 5.0 mm-thick deposits of a variety of metastable materials including amorphous alloys representing more than 15 different rare-earth-transition metal systems and a wide range of compositions and deposition conditions. The ability to prepare thick, homogeneous deposits has made it possible for the first time to investigate the structure, properties, and annealing behavior of these unique sputtered alloys using neutron diffraction, ultrasonic, and other experimental techniques that are difficult or impractical for thin films. More importantly, these characterization studies show that the structure and properties of the massive sputter deposits are independent of thickness and can be reproduced from deposit to deposit. Other advantages and applications of this metastable materials preparation technique include the possibility of varying structure and properties by control of the deposition parameters and the ability to deposit even reactive alloys with a very low impurity content

Electrospray methodologies for characterization and deposition of nanoparticles

Science.gov (United States)

Modesto Lopez, Luis Balam

Electrospray is an aerosolization method that generates highly charged droplets from solutions or suspensions and, after a series of solvent evaporation -- droplet fission cycles, it results in particles carrying multiple charges. Highly charged particles are used in a variety of applications, including particle characterization, thin film deposition, nanopatterning, and inhalation studies among several others. In this work, a soft X-ray photoionization was coupled with an electrospray to obtain monodisperse, singly charged nanoparticles for applications in online size characterization with electrical mobility analysis. Photoionization with the soft X-ray charger enhanced the diffusion neutralization rate of the highly charged bacteriophages, proteins, and solid particles. The effect of nanoparticle surface charge and nanoparticle agglomeration in liquids on the electrospray process was studied experimentally and a modified expression to calculate the effective electrical conductivity of nanosuspensions was proposed. The effective electrical conductivity of TiO2 nanoparticle suspensions is strongly dependent on the electrical double layer and the agglomeration dynamics of the particles; and such dependence is more remarkable in liquids with low ionic strength. TiO2 nanoparticle agglomerates with nearly monodisperse sizes in the nanometer and submicrometer ranges were generated, by electrospraying suspensions with tuned effective electrical conductivity, and used to deposit photocatalytic films for water-splitting. Nanostructured films of iron oxide with uniform distribution of particles over the entire deposition area were formed with an electrospray system. The micro-Raman spectra of the iron oxide films showed that transverse and longitudinal optical modes are highly sensitive to the crystallize size of the electrospray-deposited films. The fabrication of films of natural light-harvesting complexes, with the aim of designing biohybrid photovoltaic devices, was

The rain-triggered Atenquique volcaniclastic debris flow of October 16, 1955 at Nevado de Colima Volcano, Mexico

Science.gov (United States)

Saucedo, R.; Macías, J. L.; Sarocchi, D.; Bursik, M.; Rupp, B.

2008-06-01

On October 16, 1955, at 10:45 a.m. (local time), after three days of intense rain (140 mm) that was twice the monthly average precipitation, a devastating flood surge formed a volcaniclastic debris flow on the eastern slopes of Nevado de Colima Volcano. Nearly simultaneous flood surges formed in the Arroyo Seco, Los Platanos, and Dos Volcanes ravines that coalesced with the larger flow in the Atenquique ravine. At each confluence with a tributary, the flow was diluted. The texture and structure of the preserved 1955 deposits near high water marks indicate that the downstream flow was mainly in the lower range of debris flow concentration (60% sediment concentration by weight). Downstream the tributaries, the flood encountered a ˜ 0.06 × 10 6 m 3 water reservoir that failed, significantly increasing the surge volume. Additional entrained sediment also increased the flow volume. Downstream, the flood wave reached the town of Atenquique as an 8-9 m catastrophic wave causing the death of more than 23 people, the partial destruction of the town, and losses of ˜ 13,000,000 pesos (˜ 1 million US dollars today) to a paper mill and company facilities. According to eyewitness accounts the flood wave had a peak discharge that lasted ca. 10 to 15 minutes at Atenquique. Deposits at the site and the high-water marks observed from photographs of the town's church indicate that sediment concentration was ca. 60 wt.%. The flood continued for about 1 km to its junction with the Tuxpan River where it was diluted by mixing with normal flood flow. The deposits covered an area of ˜ 1.2 km 2 and had a minimum volume of ˜ 3.2 × 10 6 m 3. The main deposit consists of a single unit, averaging 4 m in thickness, with weak textural variations that suggest surging within the flood wave. The deposit is heterolithologic and consists of boulders set in a matrix of sand-size sediment, with polymodal or bimodal distributions and normal grading varying with distance from source. The town of

Petrogenesis and depositional history of felsic pyroclastic rocks from the Melka Wakena archaeological site-complex in South central Ethiopia

Science.gov (United States)

Resom, Angesom; Asrat, Asfawossen; Gossa, Tegenu; Hovers, Erella

2018-06-01

The Melka Wakena archaeological site-complex is located at the eastern rift margin of the central sector of the Main Ethiopian Rift (MER), in south central Ethiopia. This wide, gently sloping rift shoulder, locally called the "Gadeb plain" is underlain by a succession of primary pyroclastic deposits and intercalated fluvial sediments as well as reworked volcaniclastic rocks, the top part of which is exposed by the Wabe River in the Melka Wakena area. Recent archaeological survey and excavations at this site revealed important paleoanthropological records. An integrated stratigraphic, petrological, and major and trace element geochemical study has been conducted to constrain the petrogenesis of the primary pyroclastic deposits and the depositional history of the sequence. The results revealed that the Melka Wakena pyroclastic deposits are a suite of mildly alkaline, rhyolitic pantellerites (ash falls, pumiceous ash falls and ignimbrites) and slightly dacitic ash flows. These rocks were deposited by episodic volcanic eruptions during early to middle Pleistocene from large calderas along the Wonji Fault Belt (WFB) in the central sector of the MER and from large silicic volcanic centers at the eastern rift shoulder. The rhyolitic ash falls, pumiceous ash falls and ignimbrites have been generated by fractional crystallization of a differentiating basaltic magma while the petrogenesis of the slightly dacitic ash flows involved some crustal contamination and assimilation during fractionation. Contemporaneous fluvial activities in the geomorphologically active Gadeb plain deposited overbank sedimentary sequences (archaeology bearing conglomerates and sands) along meandering river courses while a dense network of channels and streams have subsequently down-cut through the older volcanic and sedimentary sequences, redepositing the reworked volcaniclastic sediments further downstream.

Characterization of bentonite clay from “Greda” deposit

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Nadežda Stanković

2011-06-01

Full Text Available Based on mineralogical and technological investigations of the deposit “Greda” important characteristics of bentonite clay were determined. Representative samples of the deposit were characterized with X-ray diffraction, low-temperature nitrogen adsorption, chemical analysis, differential thermal analysis and scanning electron microscopy. It was determined that the main mineral is montmorillonite and in subordinate quantities kaolinite, quartz and pyrite. The chemical composition generally shows high silica and alumina contents in all samples and small quantities of Fe3+, Ca2+ and Mg2+ cations. Based on technological and mineralogical research, bentonite from this deposit is a high-quality raw material for use in the ceramic industry.

Short review on chemical bath deposition of thin film and characterization

Energy Technology Data Exchange (ETDEWEB)

Mugle, Dhananjay, E-mail: dhananjayforu@gmail.com; Jadhav, Ghanshyam, E-mail: ghjadhav@rediffmail.com [Depertment of Physics, Shri Chhatrapati Shivaji College, Omerga-413606 (India)

2016-05-06

This reviews the theory of early growth of the thin film using chemical deposition methods. In particular, it critically reviews the chemical bath deposition (CBD) method for preparation of thin films. The different techniques used for characterizations of the chemically films such as X-ray diffractometer (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Electrical conductivity and Energy Dispersive Spectroscopy (EDS) are discussed. Survey shows the physical and chemical properties solely depend upon the time of deposition, temperature of deposition.

Compositional characterization of atomic layer deposited alumina

International Nuclear Information System (INIS)

Philip, Anu; Thomas, Subin; Kumar, K. Rajeev

2014-01-01

As the microelectronic industry demands feature size in the order of few and sub nanometer regime, the film composition and other film properties become critical issues and ALD has emerged as the choice of industry. Aluminum oxide is a material with wide applications in electronic and optoelectronic devices and protective and ion barrier layers. Al 2 O 3 is an excellent dielectric because of its large band gap (8.7eV), large band offsets with silicon. We have deposited thin layers of alumina on silicon wafer (p-type) for gate dielectric applications by ALD technique and compositional characterizations of the deposited thin films were done using EDS, XPS and FTIR spectra

Compositional characterization of atomic layer deposited alumina

Energy Technology Data Exchange (ETDEWEB)

Philip, Anu; Thomas, Subin; Kumar, K. Rajeev [Department of Instrumentation, Cochin University of Science and Technology, Cochin-22, Kerala (India)

2014-01-28

As the microelectronic industry demands feature size in the order of few and sub nanometer regime, the film composition and other film properties become critical issues and ALD has emerged as the choice of industry. Aluminum oxide is a material with wide applications in electronic and optoelectronic devices and protective and ion barrier layers. Al{sub 2}O{sub 3} is an excellent dielectric because of its large band gap (8.7eV), large band offsets with silicon. We have deposited thin layers of alumina on silicon wafer (p-type) for gate dielectric applications by ALD technique and compositional characterizations of the deposited thin films were done using EDS, XPS and FTIR spectra.

Insights into the Early to Late Oligocene Izu-Bonin Mariana Arc Magmatic History from Volcanic Minerals and Glass within Volcaniclastic Sediments of IODP Site U1438 and DSDP Site 296

Science.gov (United States)

Samajpati, E.; Hickey-Vargas, R.

2017-12-01

The Kyushu-Palau Ridge (KPR) is a remnant of the early Izu-Bonin-Mariana (IBM) island arc, separated by arc rifting and seafloor spreading. We examine and compare volcanic materials from two sites where the transition from IBM arc building to rifting is well sampled: DSDP Site 296 on the northern KPR crest, and recent IODP Site U1438 in the adjacent Amami-Sankaku basin to the west. The purpose of the study is to understand the origin and depositional regime of volcaniclastic sediments during the arc rifting stage. Site 1438 sedimentary Unit II and the upper part of Unit III (300 and 453 mbsf) correlate in time with sedimentary Units 1G and 2 of DSDP Site 296 (160 and 300 mbsf). The upper part of Site U1438 Unit III and Site 296 Unit 2 consist of early to late Oligocene coarse volcaniclastic sedimentary rocks. These are overlain by late Oligocene nannofossil chalks with volcanic sand and ash-rich layers at Site 296 Unit 1G, and tuffaceous silt, sand, siltstone and sandstone at Site 1438 Unit II. The chemical composition of volcanic glass shards, pyroxenes with melt inclusions and amphiboles separated from volcaniclastic sediments were analyzed by EPMA and LA-ICPMS. Glasses are found at Site 296 only, range from medium-K basalt to rhyolite and have trace element patterns typical of arc volcanics. Clinopyroxene and orthopyroxene are found as detrital grains in sediments from both sites. Mg-numbers range from 58 to 94. Interestingly, the alumina content of pyroxene grain populations from both sites increase and then decrease with decreasing Mg-number. This probably reflects control of Al contents in magma and pyroxene by suppressed plagioclase saturation, which apparently was a consistent feature of KPR volcanoes. Melt-inclusions within the pyroxenes are typically small (30-50 microns) and have similar chemical compositions within one grain. The melt inclusions range from basalt to rhyolite with moderate alkali content. Amphibole is more prevalent in late Oligocene

MIDDLE TRIASSIC AUTOCLASTIC DEPOSITS FROM SOUTHWESTERN BOSNIA AND HERZEGOVINA

Directory of Open Access Journals (Sweden)

Duje Smirčić

2016-06-01

Full Text Available Middle Triassic volcanic and volcaniclastic rocks have been recognized at several localities near Bosansko Grahovo, in southwestern part of Bosnia and Herzegovina in the External Dinarides. Peculiar types of autoclastic rocks were investigated. These are peperites and hyaloclastites. Regarding specific structures, mineral composition and micropetrographic characteristics it was possible to further differentiate hyaloclastites into in situ hyaloclastites and slightly resedimented hyaloclastites that represent genetic succession. All rock types occurred in a deep sea troughs that formed as a consequence of Middle Triassic extensional tectonic and rift related wrench faulting. In situ hyaloclastites and slightly resedimented hyaloclastites were formed due to quenching at the contact of lava effusions with sea water. Genesis of peperites is related to lava emplacement in unconsolidated water saturated lime mudstones that were deposited in deep sea basin. All investigated rock types represent first findings of autoclastic deposits in the External Dinarides. Biostratigraphic constraints achieved by means of conodont species Neogondolella excentrica, Paragondolella excelsa, Paragondolella trammeri and Gladigondolella tethydis indicate Late Anisian to Early Ladinian interval of the autoclastic deposits from Bosansko Grahovo.

Electroless deposition, post annealing and characterization of nickel ...

Indian Academy of Sciences (India)

Electroless deposition of nickel (EN) films on -type silicon has been investigated under different process conditions. The interface between the film and substrate has been characterized for electrical properties by probing the contact resistances. X-ray diffraction and atomic force microscopy have been performed to obtain ...

Study on the relationship between uranium and phosphor in deposit No.60

International Nuclear Information System (INIS)

Zhang Wanliang

1997-01-01

The deposit No.60 is a large uranium-phosphor one located at the eastern margin of the volcanic basin No.65, and controlled by the stratigraphic horizon of the middle-lower part of the third member of the Ehuling Formation composed of volcaniclastic and terrigeneous classic rocks. Uranium and phosphor were preliminarily concentrated together during the formation of ore-hosting layer, and then reactivated, transported and reprecipitated together under the action of tectonothermal process, leading to the concentration of uranium in cellophane in the adsorption state. Uranium and phosphor are closely associated with the correlation coefficient of up to 0.8-0.9

Assessment of multiple geophysical techniques for the characterization of municipal waste deposit sites

Science.gov (United States)

Gaël, Dumont; Tanguy, Robert; Nicolas, Marck; Frédéric, Nguyen

2017-10-01

In this study, we tested the ability of geophysical methods to characterize a large technical landfill installed in a former sand quarry. The geophysical surveys specifically aimed at delimitating the deposit site horizontal extension, at estimating its thickness and at characterizing the waste material composition (the moisture content in the present case). The site delimitation was conducted with electromagnetic (in-phase and out-of-phase) and magnetic (vertical gradient and total field) methods that clearly showed the transition between the waste deposit and the host formation. Regarding waste deposit thickness evaluation, electrical resistivity tomography appeared inefficient on this particularly thick deposit site. Thus, we propose a combination of horizontal to vertical noise spectral ratio (HVNSR) and multichannel analysis of the surface waves (MASW), which successfully determined the approximate waste deposit thickness in our test landfill. However, ERT appeared to be an appropriate tool to characterize the moisture content of the waste, which is of prior information for the organic waste biodegradation process. The global multi-scale and multi-method geophysical survey offers precious information for site rehabilitation studies, water content mitigation processes for enhanced biodegradation or landfill mining operation planning.

MAPLE deposition and characterization of SnO2 colloidal nanoparticle thin films

International Nuclear Information System (INIS)

Caricato, A P; Martino, M; Romano, F; Tunno, T; Valerini, D; Epifani, M; Rella, R; Taurino, A

2009-01-01

In this paper we report on the deposition and characterization of tin oxide (SnO 2 ) nanoparticle thin films. The films were deposited by the matrix-assisted pulsed laser evaporation (MAPLE) technique. SnO 2 colloidal nanoparticles with a trioctylphosphine capping layer were diluted in toluene with a concentration of 0.2 wt% and frozen at liquid nitrogen temperature. The frozen target was irradiated with a KrF (248 nm, τ = 20 ns) excimer laser (6000 pulses at 10 Hz). The nanoparticles were deposited on silica (SiO 2 ) and (1 0 0) Si substrates and submitted to morphological (high resolution scanning electron microscopy (SEM)), structural Fourier transform infrared spectroscopy (FTIR) and optical (UV-Vis transmission) characterizations. SEM and FTIR analyses showed that trioctylphosphine was the main component in the as-deposited films. The trioctylphosphine was removed after an annealing in vacuum at 400 0 C, thus allowing to get uniform SnO 2 nanoparticle films in which the starting nanoparticle dimensions were preserved. The energy gap value, determined by optical characterizations, was 4.2 eV, higher than the bulk SnO 2 energy gap (3.6 eV), due to quantum confinement effects.

Characterization of triboelectrically charged particles deposited on dielectric surfaces

Science.gov (United States)

Nesterov, A.; Löffler, F.; Cheng, Yun-Chien; Torralba, G.; König, K.; Hausmann, M.; Lindenstruth, V.; Stadler, V.; Bischoff, F. R.; Breitling, F.

2010-04-01

A device for the measurement of q/m-values and charge degradation of triboelectrically charged particles deposited on a surface was developed. The setup is based on the integration of currents, which are induced in a Faraday cage by insertion of a solid support covered with charged particles. The conductivity of different particle supports was taken into account. The 'blow-off' method, in which the particles are first deposited, and then blown off using an air stream, can be used for characterization of triboelectric properties of particles relative to different surfaces.

Characterization of triboelectrically charged particles deposited on dielectric surfaces

Energy Technology Data Exchange (ETDEWEB)

Nesterov, A; Torralba, G; Hausmann, M; Lindenstruth, V [Kirchhoff Institute of Physics, In Neuenheimer Feld 227, Heidelberg (Germany); Loeffler, F; Cheng, Yun-Chien; Koenig, K; Stadler, V; Bischoff, F R [German Cancer Research Centre, In Neuenheimer Feld 280, Heidelberg (Germany); Breitling, F, E-mail: Frank.Breitling@KIT.ed, E-mail: alexander.nesterov-mueller@kit.ed [Karlsruhe Institute of Technology (KIT), Institute for Microstructure Technology, Herrmann von Helmholtzplatz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2010-04-28

A device for the measurement of q/m-values and charge degradation of triboelectrically charged particles deposited on a surface was developed. The setup is based on the integration of currents, which are induced in a Faraday cage by insertion of a solid support covered with charged particles. The conductivity of different particle supports was taken into account. The 'blow-off' method, in which the particles are first deposited, and then blown off using an air stream, can be used for characterization of triboelectric properties of particles relative to different surfaces.

Correlation and stratigraphic eruption age of the pyroclastic flow deposits and wide spread volcanic ashes intercalated in the Pliocene-Pleistocene strata, central Japan

International Nuclear Information System (INIS)

Nagahashi, Yoshitaka; Satoguchi, Yasufumi; Yoshikawa, Shusaku

2000-01-01

Three pyroclastic flow deposits in the Takayama and Omine area, central Honshu, are correlated to the distal widespread volcanic ashes intercalated in the Plio-Pleistocene boundary strata in central Japan. The correlation is based on these stratigraphic relationships, facies, magnetostratigraphy, petrographic properties such as mineral assemblage, refractive index and chemical composition of the volcanic glasses and orthopyroxene. As the result of these correlation, the eruption age of the proximal pyroclastic flow deposits have become clear. And precise correlation between proximal eruption units and distal depositional units is now possible. Ho-Kd 39 Tephra erupted at about 1.76 Ma, forming a co-ignimbrite ash, which deposited in the Kanto sedimentary basin. Eb-Fukuda Tephra erupted at about 1.75 Ma, and distal volcaniclastic deposit sedimented in the Kinki, Niigata and Kanto sedimentary basins. The eruptional and depositional phase are divided into the stage 1, stage 2 (early), stage 2 (late) and stage 3. Stage 1 is phreato-plinian type eruption phase, forming distal ash fall deposit. Stage 2 (early) is plinian pumice fall, intra-plinian pyroclastic flow and plinian pumice fall eruption phase, forming distal ash fall. Stage 2 (late) is final eruptional phase of the biggest pyroclastic flow of the Eb-Fukuda Tephra, forming a co-ignimbrite ash fall. Stage 3 is resedimented stage after the end of the explosive eruption. It is notable that resedimented volcaniclastic deposit reached Osaka sedimentary basin 300 km away from the eruption center. Om-SK110 Tephra erupted at about 1.65 Ma, divided into the stage 1, stage 2 and stage 3. Stage 1 is eruption phase of the plinian pumice fall and first pyroclastic flow. Stage 2 is pauses in eruption activity. Stage 3 is second pyroclastic flow phase, it is inferred that the pyroclastic flow of the stage 3 directly entered the Niigata sedimentary basin and simultaneously formed a co-ignimbrite ash. (author)

Structural characterization of the nickel thin film deposited by glad technique

Directory of Open Access Journals (Sweden)

Potočnik J.

2013-01-01

Full Text Available In this work, a columnar structure of nickel thin film has been obtained using an advanced deposition technique known as Glancing Angle Deposition. Nickel thin film was deposited on glass sample at the constant emission current of 100 mA. Glass sample was positioned 15 degrees with respect to the nickel vapor flux. The obtained nickel thin film was characterized by Force Modulation Atomic Force Microscopy and by Scanning Electron Microscopy. Analysis indicated that the formation of the columnar structure occurred at the film thickness of 1 μm, which was achieved for the deposition time of 3 hours. [Projekat Ministarstva nauke Republike Srbije, br. III45005

Soft sediment deformation structures in a lacustrine sedimentary succession induced by volcano-tectonic activities: An example from the Cretaceous Beolgeumri Formation, Wido Volcanics, Korea

Science.gov (United States)

Ko, Kyoungtae; Kim, Sung Won; Lee, Hong-Jin; Hwang, In Gul; Kim, Bok Chul; Kee, Won-Seo; Kim, Young-Seog; Gihm, Yong Sik

2017-08-01

The Cretaceous Beolgeumri Formation is composed of laminated mudstones intercalated with sandstones, chert, and a bed of lapilli tuff that were deposited in a lacustrine environment at the terminal part of a regional strike-slip fault systems on the southwestern Korean Peninsula. The Beolgeumri Formation contains various types of soft sediment deformation (SSD) structures that are characterized by a wide extent (features and deformation styles: 1) fold structures, 2) load structures, 3) water-escape structures, 4) rip-down structures, 5) boudin structures, and 6) synsedimentary fault structures. Field examination of SSD structures together with an analysis of the sedimentological records of the Beolgeumri Formation indicate that the SSD structures formed largely by liquefaction and/or fluidization triggered by ground shaking during earthquakes. To constrain the timing of the development of SSD structures in the Beolgeumri Formation, we conducted sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon age dating of block sized lithic clasts bearing volcaniclastic deposits that conformably underlie (the Mangryeongbong Tuff) and overlie (the Ttandallae Tuff) the Beolgeumri Formation. The Mangryeongbong and Ttandallae Tuffs have ages of 86.63 ± 0.83 Ma and 87.24 ± 0.36 Ma, respectively, indicating that the Beolgeumri Formation was deposited during a short interval between major volcanic eruptions. The large lithic clasts of volcaniclastic deposits suggest that the Beolgeumri Formation was deposited adjacent to an active volcanic edifice(s). Syndepositional magmatic activities are suggested by the occurrence of a lapilli tuff bed in the Beolgeumri Formation and an igneous intrusion (intermediate sill) that is crosscut by a sand dike, as well as the similar age results of the underlying and overlying volcaniclastic deposits. Thus, we infer that the earthquakes that caused the development of SSD structures in the study area were closely related to syndepositional

Characterization of thin CeO{sub 2} films electrochemically deposited on HOPG

Energy Technology Data Exchange (ETDEWEB)

Faisal, Firas [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Toghan, Arafat, E-mail: arafat.toghan@yahoo.com [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Chemistry Department, Faculty of Science, South Valley University, 83523 Qena (Egypt); Khalakhan, Ivan; Vorokhta, Mykhailo; Matolin, Vladimír [Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 747/2, 180 00 Prague 8 (Czech Republic); Libuda, Jörg [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Erlangen Catalysis Resource Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany)

2015-09-30

Graphical abstract: - Highlights: • Preparation of proton exchange membrane fuel cells catalyst using electrochemical thin film deposition. • Electrodeposition thin films of CeO{sub 2} on HOPG substrates. • The samples were characterized by in-situ AFM and ex-situ XPS. • XPS results reveal that the electrochemically deposited cerium oxide films are stoichiometric. • Exposing the films to ambient air, cracking structures are formed. - Abstract: Electrodeposition is widely used for industrial applications to deposit thin films, coatings, and adhesion layers. Herein, CeO{sub 2} thin films were deposited on a highly oriented pyrolytic graphite (HOPG) substrate by cathodic electrodeposition. The influence of the deposition parameters on the yield and on the film morphology is studied and discussed. Morphology and composition of the electrodeposited films were characterized by in-situ atomic force microscopy (AFM), scanning electron microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). By AFM we show that the thickness of CeO{sub 2} films can be controlled via the Ce{sup 3+} concentration in solution and the deposition time. After exposing the films to ambient air, cracking structures are formed, which were analyzed by AFM in detail. The chemical composition of the deposits was analyzed by XPS indicating the formation of nearly stoichiometric CeO{sub 2}.

Characterization of Minerals: From the Classroom to Soils to Talc Deposits

Science.gov (United States)

McNamee, Brittani D.

2013-01-01

This dissertation addresses different methods and challenges surrounding characterizing and identifying minerals in three environments: in the classroom, in soils, and in talc deposits. A lab manual for a mineralogy and optical mineralogy course prepares students for mineral characterization and identification by giving them the methods and tools…

Uranium deposit types and resources of Argentina

International Nuclear Information System (INIS)

Lopez, L.; Cuney, M.

2014-01-01

The uranium-related activities in Argentina begun in the 1950s and, as a result of the systematic exploration, several types of deposits have been discovered since then: volcanic and caldera-related, sandstone-hosted, vein spatially related to granite (intragranitic and perigranitic) and surficial. The deposits that have been the focus of the most important uranium exploitations are the ones that belong to the volcaniclastic type. These are localized in Permian formations associated with synsedimentary acid volcanism in the Sierra Pintada district (Mendoza province). The volcanic and caldera related type is also present in the Laguna Colorada deposit (Chubut province) located in the San Jorge basin (Cretaceous). Several important uranium mineralisations have been identified in Cretaceous fluvial sandstones and conglomerates, among which the most relevant is the Cerro Solo deposit (Chubut province) that corresponds to the paleochannel structure subtype. Other subtypes of sandstone model have been studied. For instance, the Don Otto deposit (Salta province), located in the Salta Group Basin (Cretaceous - Tertiary), belongs to the tabular U-V subtype. The roll front subtype can be also found in the Los Mogotes Colorados deposit (La Rioja province) which is hosted by Carboniferous continental sandstones. The uranium mineralisations in veins and disseminated episyenites within peraluminous leucogranites of the Sierras Pampeanas (Cordoba and San Luis provinces) represent other types of existing deposits. These granites are Devonian – Carboniferous and the related deposits are comparable to those from the Middle European Variscan. There are also other vein-type uranium deposits located in metamorphic basement in the periphery of high potassium calcalkaline granites (Sierras Pampeanas of Catamarca and La Rioja provinces), where the mineralisation control is mainly structural. The current uranium identified resources of the country are approximately 24,000 tU in the

Chemical bath deposition of indium sulphide thin films: preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Lokhande, C.D.; Ennaoui, A.; Patil, P.S.; Giersig, M.; Diesner, K.; Muller, M.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

1999-02-26

Indium sulphide (In{sub 2}S{sub 3}) thin films have been successfully deposited on different substrates under varying deposition conditions using chemical bath deposition technique. The deposition mechanism of In{sub 2}S{sub 3} thin films from thioacetamide deposition bath has been proposed. Films have been characterized with respect to their crystalline structure, composition, optical and electrical properties by means of X-ray diffraction, TEM, EDAX, optical absorption, TRMC (time resolved microwave conductivity) and RBS. Films on glass substrates were amorphous and on FTO (flourine doped tin oxide coated) glass substrates were polycrystalline (element of phase). The optical band gap of In{sub 2}S{sub 3} thin film was estimated to be 2.75 eV. The as-deposited films were photoactive as evidenced by TRMC studies. The presence of oxygen in the film was detected by RBS analysis. (orig.) 27 refs.

Deposition and Characterization of Thin Films on Metallic Substrates

Science.gov (United States)

Gatica, Jorge E.

2005-01-01

A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films

Plio-quaternary deposits in the Eastern Rharb (Nw Morocco): Electrosequential characterization

Science.gov (United States)

Al Mazini, Imane; Mridekh, Abdelaziz; Kili, Malika; El Mansouri, Bouâbid; El Bouhaddioui, Mohamed; Magrane, Bouchaib

2018-02-01

The Rharb basin, of which our study area is part, is located at the western extremity of the south Rif corridor. It corresponds to a subsiding zone that appeared in the Upper Miocene, between two major structural domains: the Rif to the north and east and the Meseta domain to the south. The eastern part of this basin is characterized by a Plio-Quaternary continental fill. Its geographical position and its structural and paleo-environmental contexts are reflected by a great facies heterogeneity. This work aims to image the subsurface structure and to characterize the distribution mode of Plio-Quaternary deposits of the eastern Rharb. The use of a database consisting of geo-electrical cross sections, hydrogeological drilling and wireline logging integrated in a Geographic Information System (GIS) allowed us to establish a new three-dimensional model of the top of the Mio-Pliocene substratum, new geo-electrical cross sections, as well as the isopach maps of lower, intermediate, upper and superficial geo-electric interval. This approach allowed us to characterize the Plio-Quaternary deposits of the study area and to highlight the effects of the tectonic regime and the relative sea level fluctuations on the sequential organization of these deposits. Our new model shows the development of prograding, aggrading and retrograding parasequences denoting the existence of autogenic mechanisms in the organization of plio-quaternary deposits of the eastern part of the Rharb basin. Therefore, it opens new perspectives for the exploration of water resources and monitoring their quality throughout the basin.

Characterization of Ibere and Oboro clay deposits in Abia state ...

African Journals Online (AJOL)

Ibere and Oboro clay deposits in Ikwuano, Abia State of Nigeria were characterized for refractory and other applications. The characteristics investigated were mineralogical composition, chemical composition, plasticity, linear shrinkage, apparent porosity, bulk density, cold crushing strength, thermal shock resistance, ...

Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation

International Nuclear Information System (INIS)

Rebollo P, B.

2001-01-01

The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp 2 and sp 3 bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

Mineralogical, IR-spectral and geochemical monitoring of hydrothermal alteration in a deformed and metamorphosed Jurassic VMS deposit at Arroyo Rojo, Tierra del Fuego, Argentina

Science.gov (United States)

Biel, C.; Subías, I.; Acevedo, R. D.; Yusta, I.; Velasco, F.

2012-04-01

The Arroyo Rojo Zn-Pb-Cu volcanogenic massive sulfide deposit is the main deposit of the Fin del Mundo District in the Fuegian Andes, Argentina. This deposit is hosted by a Middle Jurassic volcanic and volcanoclastic sequence forming the Lemaire Formation. The latter consists, from the base up, of the following: rhyolitic and dacitic porphyritic rocks, ignimbrite, tuff, and flow. It is underlain by a pre-Jurassic basement and overlain by the hyaloclastic andesites of the Yahgán Formation. The Arroyo Rojo consists of stacked lenticular lenses that are associated with disseminated mineralization in both the footwall and the hanging wall. The internal structure of the ore lenses is marked by the occurrence of massive, semi-massive and banded facies, along with stringer and brecciated zones and minor ore disseminations. The mineral assemblage comprises mainly pyrite and sphalerite, with minor amounts of galena and chalcopyrite and rare pyrrhotite, arsenopyrite, tetrahedrite and bournonite. The ores and the volcanic host rocks have metamorphosed to greenschist facies and were overprinted by a penetrative tectonic foliation, which led to the development of mylonitic, and cataclastic textures, recrystallization and remobilization. Primary depositional characteristics and regional and hydrothermal alteration patterns were preserved despite deformation and metamorphism. Therefore, primary banding was preserved between facies boundaries. In addition, some remnants of magmatic origin are recognizable in preserved phenocrysts and volcaniclastic phenoclasts. Most of the volcanic and volcaniclastic rocks of the host sequence show a rhyolitic to rhyo-dacitic composition. Regional seafloor alteration, characterized by the presence of clinozoisite, Fe-chlorite and titanite, along with quartz and albite, is partially obliterated by hydrothermal alteration. The hydrothermal alteration is stratabound with the following assemblages, which developed from the base to top: (1) Quartz

Water-rock interactions in volcaniclastic sediments across the Izu-Bonin-Mariana Arc: comparison of sites U1438, U1201, 792 and 793.

Science.gov (United States)

van der Land, C.; Sena, C.; Loudin, L. C.; Zhang, Z.

2014-12-01

The rapid deposition of volcanogenic sediments, highly susceptible to alteration by seawater has led to distinct pore water geochemical profiles throughout the sedimentary basins of the Izu-Bonin-Mariana Arc. Drilling at Site U1438, in the Amami-Sankaku Basin, recovered a 1300 m thick volcaniclastic section overlain by a 160 m thick section of sediments largely devoid of volcanic input. At Site U1438, 67 porewater samples were analyzed onboard for salinity, pH, oxidation-reduction potential and major and trace element concentrations. Here we focus on the depth profiles of elements which were also analyzed at Sites U1201, 792 and 793. Chloride and Bromide concentrations display similar trends; near constant in the upper 160 m and a linear downward increase to maximum concentrations from 600 mbsf onwards. This increase is likely caused by uptake of water by secondary minerals, resulting in chloride and bromide enrichment in the porewater. Calcium and magnesium porewater concentrations display opposite trends in the upper 440 m; the first increases from 11.5 to 140 mM, and the latter decreases from 53 mM until its depletion in the porewater. Leaching of Ca from the glass-rich sediments and underlying igneous basement are potential sources for Ca in the porewater, while Mg, Na and K presumably replace Ca through cation-exchange. Compared to Site U1438, similar trends of major elements concentration in the pore water were observed at the nearby Sites U1201 (serpentine mud volcano in the forearc of the Mariana subduction system), 792 and 793 (both in the Izu-Bonin forearc sedimentary basin). However, differences in depositional rates, thickness and age of the sedimentary basins, geothermal gradients and the influence of serpentine mud flows, have led to distinct pore water geochemical profiles.

Depositional environment of the Onverwacht sedimentary rocks Barberton greenstone belt, South Africa

Science.gov (United States)

Paris, I. A.

The Onverwacht Group is the basal part of the ca 3.5 Ga succession forming the Barberton greenstone belt. It comprises a volcanic pile overlain by a thin layer of volcaniclastic sediments which, due to silicification, are extremely well preserved. There has been a controversy as to how and in what environment these sediments were formed, different sets of data being presented to reach opposite conclusions. The Onverwacht Group has been extensively repeated tectonically and here for the first time, sediments from different structural levels are studied together. Three separate facies have been recognised, a distal and proximal turbidite facies and a subaerial facies. Deposition of Onverwacht Group sedimentary rocks occurred in an oceanic basin characterised by the presence of emergent volcanic islands. After eruption, material was deposited both subaerially and in a shallow submarine environment on the volcanic slopes and, as a result of pyroclastic flow, in the deeper parts of the basin.

Synthesis and characterization of titanium dioxide thin films deposited by laser ablation

International Nuclear Information System (INIS)

Escobar A, L.; Camps C, E.; Falcon B, T.; Carapia M, L.; Haro P, E.; Camacho L, M.A.

2000-01-01

In this work are presented the results obtained when TiO 2 thin films were deposited using the laser ablation technique. Thin films were deposited at different substrate temperatures, and different oxygen pressures, with the purpose of studying the influence of this deposit parameters in the structural characteristics of the films obtained. The structural characterization was realized through Raman Spectroscopy and X-ray Diffraction (XRD), the surface morphology of the layers deposited was verified by Scanning Electron Microscopy (Sem). The results show that the films obtained are of TiO 2 in rutile phase, getting this at low substrate temperatures, its morphology shows a soft surface with some spattered particles and good adherence. (Author)

Satellite-Based Thermophysical Analysis of Volcaniclastic Deposits: A Terrestrial Analog for Mantled Lava Flows on Mars

Directory of Open Access Journals (Sweden)

Mark A. Price

2016-02-01

Full Text Available Orbital thermal infrared (TIR remote sensing is an important tool for characterizing geologic surfaces on Earth and Mars. However, deposition of material from volcanic or eolian activity results in bedrock surfaces becoming significantly mantled over time, hindering the accuracy of TIR compositional analysis. Moreover, interplay between particle size, albedo, composition and surface roughness add complexity to these interpretations. Apparent Thermal Inertia (ATI is the measure of the resistance to temperature change and has been used to determine parameters such as grain/block size, density/mantling, and the presence of subsurface soil moisture/ice. Our objective is to document the quantitative relationship between ATI derived from orbital visible/near infrared (VNIR and thermal infrared (TIR data and tephra fall mantling of the Mono Craters and Domes (MCD in California, which were chosen as an analog for partially mantled flows observed at Arsia Mons volcano on Mars. The ATI data were created from two images collected ~12 h apart by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER instrument. The results were validated with a quantitative framework developed using fieldwork that was conducted at 13 pre-chosen sites. These sites ranged in grain size from ash-sized to meter-scale blocks and were all rhyolitic in composition. Block size and mantling were directly correlated with ATI. Areas with ATI under 2.3 × 10−2 were well-mantled with average grain size below 4 cm; whereas values greater than 3.0 × 10−2 corresponded to mantle-free surfaces. Correlation was less accurate where checkerboard-style mixing between mantled and non-mantled surfaces occurred below the pixel scale as well as in locations where strong shadowing occurred. However, the results validate that the approach is viable for a large majority of mantled surfaces on Earth and Mars. This is relevant for determining the volcanic history of Mars, for

Flood deposits characterization in Matraca community, Guainia Department in Colombia

International Nuclear Information System (INIS)

Cramer, T.; Molano, J.; Bonilla, A.; Amaya, Z.; Franco, J.; Iregui, I.

2010-01-01

The characterization of alluvial deposits found in the indigenous community of Matraca is a study that requires mineralogical, petrographic, sedimentological, geochemical and physical analyzes.The results obtained from these analyzes bring the certainty to be in the presence of economically exploitable mineral columbite-tantalite of the series field

Deposition and Characterization of HVOF Thermal Sprayed Functionally Graded Coatings Deposited onto a Lightweight Material

Science.gov (United States)

Hasan, M.; Stokes, J.; Looney, L.; Hashmi, M. S. J.

2009-02-01

There is a significant interest in lightweight materials (like aluminum, magnesium, titanium, and so on) containing a wear resistance coating, in such industries as the automotive industry, to replace heavy components with lighter parts in order to decrease vehicle weight and increase fuel efficiency. Functionally graded coatings, in which the composition, microstructure, and/or properties vary gradually from the bond coat to the top coat, may be applied to lightweight materials, not only to decrease weight, but also to enhance components mechanical properties by ensuring gradual microstructural (changes) together with lower residual stress. In the current work, aluminum/tool-steel functionally graded coatings were deposited onto lightweight aluminum substrates. The graded coatings were then characterized in terms of residual stress and hardness. Results show that residual stress increased with an increase in deposition thickness and a decrease in number of layers. However, the hardness also increased with an increase in deposition thickness and decrease in number of layers. Therefore, an engineer must compromise between the hardness and stress values while designing a functionally graded coating-substrate system.

"{Deposition and characterization of multilayers on thin foil x-ray

DEFF Research Database (Denmark)

Hussain, A.M.; Joensen, K.D.; Hoeghoej, P.

1996-01-01

W/Si and Co/C multilayers have been deposited on epoxy- replicated Au mirrors from the ASTRO-E telescope project, SPectrum Roentgen Gamma (SRG) flight mirrors, DURAN glass substrates and Si witness wafers. A characterization of the multilayers with both hard x-rays and soft x-rays is presented. T...

Chemical characterization of biomass burning deposits from cooking stoves in Bangladesh

International Nuclear Information System (INIS)

Salam, Abdus; Hasan, Mahmodul; Begum, Bilkis A.; Begum, Monira; Biswas, Swapan K.

2013-01-01

Biomass burning smoke deposits were characterized from cooking stoves in Brahmondi, Narsingdi, Bangladesh. Arjun, bamboo, coconut, madhabilata, mahogany, mango, rice husk coil, plum and mixed dried leaves were used as biomasses. Smoke deposits were collected from the ceiling (above the stove) of the kitchen on aluminum foil. Deposits samples were analyzed with X-ray fluorescence (XRF) spectroscopy for trace elements determination. UV–visible spectrophotometer was used for ions analysis. The surface morphology of the smoke deposits was studied with scanning electron microscope (SEM). Elevated concentrations of the trace elements were observed, especially for toxic metals (Pb, Co, Cu). The highest concentration of lead was observed in rice husk coil among the determined biomasses followed by mahogany and arjun, whereas the lowest concentration was observed in bamboo. Potassium has the highest concentration among the determined trace elements followed by calcium, iron and titanium. Trace elements such as potassium, calcium, iron showed significant variation among different biomass burning smoke deposits. The average concentrations of sulfate, nitrate, and phosphate were 38.0, 0.60, 0.73 mg kg −1 , respectively. The surface morphology was almost similar for these biomass burning deposit samples. The Southeast Asian biomass burning smoke deposits had distinct behavior from European and USA wood fuels combustion. -- Highlights: •Elevated concentrations of trace elements were observed in biomass burning deposits. •Very high concentration of lead was observed in biomasses burring deposits •Elevated toxic trace elements concentrations in kitchens need further surveillance

Methods for the characterization of pyrolytic deposited carbon

International Nuclear Information System (INIS)

Bongartz, K.; Hoven, H.; Koizlik, K.

Pyrocarbon is deposited as a coating material on fuel kernels used in HTGRs. For the development of particle coatings specified for various reactor designs, it is necessary to know the properties of pyrocarbon and their changes by neutron irradiation. In this report, procedures are described which are used to characterize pyrocarbon: measurement of geometry, density, microporosity, apparent crystallite size, anisotropy of orientation, modulus of elasticity, and strength of coatings, as well as ceramography, etching by oxidation, secondary and transmission electron microscopy. (auth)

Deposition and characterization of CuInSe2 thin films

International Nuclear Information System (INIS)

Dhere, N.G.; Ferreira, C.L.; Cruz, L.R.O.; Mattoso, I.G.; Alves, R.M.P.

1988-01-01

CuInSe 2 thin films with 1,3 to 1,7 μm of thickness were deposited by the constituent elements (copper, indium and selenium) in glass substrate. The producted films were characterized by scanning microscopy, X-ray diffraction, Auger electron spectroscopy, Hall effect measures and optical absorption. (C.G.C.) [pt

The Cannery Formation--Devonian to Early Permian arc-marginal deposits within the Alexander Terrane, Southeastern Alaska

Science.gov (United States)

Karl, Susan M.; Layer, Paul W.; Harris, Anita G.; Haeussler, Peter J.; Murchey, Benita L.

2011-01-01

cherts on both Admiralty and Kupreanof Islands contain radiolarians as young as Permian, the age of the Cannery Formation is herein extended to Late Devonian through early Permian, to include the early Permian rocks exposed in its type locality. The Cannery Formation is folded and faulted, and its stratigraphic thickness is unknown but inferred to be several hundred meters. The Cannery Formation represents an extended period of marine deposition in moderately deep water, with slow rates of deposition and limited clastic input during Devonian through Pennsylvanian time and increasing argillaceous, volcaniclastic, and bioclastic input during the Permian. The Cannery Formation comprises upper Paleozoic rocks in the Alexander terrane of southeastern Alaska. In the pre-Permian upper Paleozoic, the tectonic setting of the Alexander terrane consisted of two or more evolved oceanic arcs. The lower Permian section is represented by a distinctive suite of rocks in the Alexander terrane, which includes sedimentary and volcanic rocks containing early Permian fossils, metamorphosed rocks with early Permian cooling ages, and intrusive rocks with early Permian cooling ages, that form discrete northwest-trending belts. After restoration of 180 km of dextral displacement of the Chilkat-Chichagof block on the Chatham Strait Fault, these belts consist, from northeast to southwest, of (1) bedded chert, siliceous argillite, volcaniclastic turbidites, pillow basalt, and limestone of the Cannery Formation and the Porcupine Slate of Gilbert and others (1987); (2) greenschist-facies Paleozoic metasedimentary and metavolcanic rocks that have Permian cooling ages; (3) silty limestone and calcareous argillite interbedded with pillow basalt and volcaniclastic rocks of the Halleck Formation and the William Henry Bay area; and (4) intermediate-composition and syenitic plutons. These belts correspond to components of an accretionary complex, contemporary metamorphic rocks, forearc-basin deposits,

Preparation and characterization of thin organosilicon films deposited on SPR chip

Energy Technology Data Exchange (ETDEWEB)

Szunerits, Sabine [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces (LEPMI), CNRS-INPG-UJF, 1130 rue de la piscine, BP 75, 38402 St. Martin d' Heres Cedex (France)], E-mail: sabine.szunerits@lepmi.inpg.fr; Rich, Sami Abou [Laboratoire de Genie des Procedes d' Interaction de Fluides Reactifs-Materiaux U.S.T.L., Cite Scientifique, 59655 Villeneuve d' Ascq (France); Coffinier, Yannick [Institut de Recherche Interdisciplinaire (IRI), FRE CNRS 2963, Institut d' lectronique, de Microelectronique et de Nanotechnologie (IEMN), UMR CNRS-8520, Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Languille, Marie-Angelique [Unite de Catalyse et de Chimie du Solide, UCCS UMR CNRS-8181, Universite des Sciences et Technologies de Lille, Bat. C3, 59655 Villeneuve d' Ascq (France); Supiot, Philippe [Laboratoire de Genie des Procedes d' Interaction de Fluides Reactifs-Materiaux U.S.T.L., Cite Scientifique, 59655 Villeneuve d' Ascq (France); Boukherroub, Rabah [Institut de Recherche Interdisciplinaire (IRI), FRE CNRS 2963, Institut d' lectronique, de Microelectronique et de Nanotechnologie (IEMN), UMR CNRS-8520, Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France)], E-mail: rabah.boukherroub@iemn.univ-lille1.fr

2008-04-20

The paper reports on the preparation and characterization of organosilicon thin polymer films deposited on glass slides coated with 5 nm adhesion layer of titanium and 50 nm of gold. The polymer was obtained by the decomposition of 1,1,3,3-tetramethyldisiloxane precursor (TMDSO) premixed with oxygen induced in a N{sub 2} plasma afterglow using remote plasma-enhanced chemical vapor deposition (PECVD) technique. The film thickness was controlled by laser interferometry and was 9 nm. The chemical stability of the gold substrate coated with the organosilicon polymer film (p-TMDSO) was studied in different acidic and basic solutions (pH 1-14). While the gold/polymer interface showed a high stability in acidic media, the film was almost completely removed in basic solutions. The resulting surfaces were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), water contact angle measurements, cyclic voltammetry, and surface plasmon resonance (SPR)

Preparation and characterization of thin organosilicon films deposited on SPR chip

International Nuclear Information System (INIS)

Szunerits, Sabine; Rich, Sami Abou; Coffinier, Yannick; Languille, Marie-Angelique; Supiot, Philippe; Boukherroub, Rabah

2008-01-01

The paper reports on the preparation and characterization of organosilicon thin polymer films deposited on glass slides coated with 5 nm adhesion layer of titanium and 50 nm of gold. The polymer was obtained by the decomposition of 1,1,3,3-tetramethyldisiloxane precursor (TMDSO) premixed with oxygen induced in a N 2 plasma afterglow using remote plasma-enhanced chemical vapor deposition (PECVD) technique. The film thickness was controlled by laser interferometry and was 9 nm. The chemical stability of the gold substrate coated with the organosilicon polymer film (p-TMDSO) was studied in different acidic and basic solutions (pH 1-14). While the gold/polymer interface showed a high stability in acidic media, the film was almost completely removed in basic solutions. The resulting surfaces were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), water contact angle measurements, cyclic voltammetry, and surface plasmon resonance (SPR)

Design and spectroscopic reflectometry characterization of pulsed laser deposition combinatorial libraries

International Nuclear Information System (INIS)

Schenck, Peter K.; Bassim, Nabil D.; Otani, Makoto; Oguchi, Hiroyuki; Green, Martin L.

2007-01-01

The goal of the design of pulsed laser deposition (PLD) combinatorial library films is to optimize the compositional coverage of the films while maintaining a uniform thickness. The deposition pattern of excimer laser PLD films can be modeled with a bimodal cos n distribution. Deposited films were characterized using a spectroscopic reflectometer (250-1000 nm) to map the thickness of both single composition calibration films and combinatorial library films. These distribution functions were used to simulate the composition and thickness of multiple target combinatorial library films. The simulations were correlated with electron-probe microanalysis wavelength-dispersive spectroscopy (EPMA-WDS) composition maps. The composition and thickness of the library films can be fine-tuned by adjusting the laser spot size, fluence, background gas pressure, target geometry and other processing parameters which affect the deposition pattern. Results from compositionally graded combinatorial library films of the ternary system Al 2 O 3 -HfO 2 -Y 2 O 3 are discussed

A robotic system to characterize soft tailings deposits

Energy Technology Data Exchange (ETDEWEB)

Lipsett, M.G.; Dwyer, S.C. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

2009-07-01

A robotic system for characterizing soft tailings deposits was discussed in this presentation. The system was developed to reduce variability in feedstocks and process performance as well as to improve the trafficability of composite tailings (CT). The method was designed to reliably sample different locations of a soft deposit. Sensors were used to determine water content, clay content, organic matter, and strength. The system included an autonomous rover with a sensor package and teleoperation capability. The system was also designed to be used without automatic controls. The wheeled mobile robot was used to conduct ground contact and soil measurements. The gas-powered robot included on-board microcontrollers and a host computer. The system also featured traction control and fault recovery sub-systems. Wheel contact was used to estimate soil parameters. It was concluded that further research is needed to improve traction control and soil parameter estimation testing capabilities. Overall system block diagrams were included. tabs., figs.

Generation of Silicic Melts in the Early Izu-Bonin Arc Recorded by Detrital Zircons in Proximal Arc Volcaniclastic Rocks From the Philippine Sea

Science.gov (United States)

Barth, A. P.; Tani, K.; Meffre, S.; Wooden, J. L.; Coble, M. A.; Arculus, R. J.; Ishizuka, O.; Shukle, J. T.

2017-10-01

A 1.2 km thick Paleogene volcaniclastic section at International Ocean Discovery Program Site 351-U1438 preserves the deep-marine, proximal record of Izu-Bonin oceanic arc initiation, and volcano evolution along the Kyushu-Palau Ridge (KPR). Pb/U ages and trace element compositions of zircons recovered from volcaniclastic sandstones preserve a remarkable temporal record of juvenile island arc evolution. Pb/U ages ranging from 43 to 27 Ma are compatible with provenance in one or more active arc edifices of the northern KPR. The abundances of selected trace elements with high concentrations provide insight into the genesis of U1438 detrital zircon host melts, and represent useful indicators of both short and long-term variations in melt compositions in arc settings. The Site U1438 zircons span the compositional range between zircons from mid-ocean ridge gabbros and zircons from relatively enriched continental arcs, as predicted for melts in a primitive oceanic arc setting derived from a highly depleted mantle source. Melt zircon saturation temperatures and Ti-in-zircon thermometry suggest a provenance in relatively cool and silicic melts that evolved toward more Th and U-rich compositions with time. Th, U, and light rare earth element enrichments beginning about 35 Ma are consistent with detrital zircons recording development of regional arc asymmetry and selective trace element-enriched rear arc silicic melts as the juvenile Izu-Bonin arc evolved.

Investigation on characterization of Ereen coal deposit

Directory of Open Access Journals (Sweden)

S. Jargalmaa

2016-03-01

Full Text Available The Ereen coal deposit is located 360 km west from Ulaanbaatar and 95 km from Bulgan town. The coal reserve of this deposit is approximately 345.2 million tons. The Ereen coal is used directly for the Erdenet power plant for producing of electricity and heat. The utilization of this coal for gas and liquid product using gasification and pyrolysis is now being considered. The proximate and ultimate analysis show that the Ereen coal is low rank D mark hard coal, which corresponds to subbituminous coal. The SEM images of initial coal sample have compact solid pieces. The SEM image of carbonized and activated carbon samples are hard material with high developed macro porosity structure. The SEM images of hard residue after thermal dissolution in autoclave characterizes hard pieces with micro porous structure in comparison with activated carbon sample. The results of the thermal dissolution of Ereen coal in tetralin with constant weight ratio between coal and tetralin (1:1.8 at the 450ºC show that 38% of liquid product can be obtained by thermal decomposition of the COM (coal organic matter.Mongolian Journal of Chemistry 16 (42, 2015, 18-21

Deposition and characterization of ZnO/NiO thin films

Energy Technology Data Exchange (ETDEWEB)

Vijayaprasath, G.; Sakthivel, P.; Murugan, R.; Ravi, G., E-mail: raviganesa@rediffmail.com, E-mail: gravicrc@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004 (India); Mahalingam, T. [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of)

2016-05-23

In this work, p-n heterojunctions based on p-NiO and n-ZnO composite nanostructures were successfully deposited by sol-gel spin coating method. Structural investigations indicate well aligned ZnO nanorods with hexagonal faces having a preferential orientation along the c-axis (002). Scanning electron microscopy (SEM) was used to characterize, the p-n heterostructures formed grain like spherical structure of NiO fully covered the hexagonal rods of ZnO in the NiO/ZnO thin film and elements were confirmed from EDX analysis. PL and micro-Raman spectra of the deposited films showed the variation in luminescence and structural properties due to the formation of heterojuction of NiO.

Metalorganic chemical vapor deposition and characterization of ZnO materials

Science.gov (United States)

Sun, Shangzu; Tompa, Gary S.; Hoerman, Brent; Look, David C.; Claflin, Bruce B.; Rice, Catherine E.; Masaun, Puneet

2006-04-01

Zinc oxide is attracting growing interest for potential applications in electronics, optoelectronics, photonics, and chemical and biochemical sensing, among other applications. We report herein our efforts in the growth and characterization of p- and n-type ZnO materials by metalorganic chemical vapor deposition (MOCVD), focusing on recent nitrogen-doped films grown using diethyl zinc as the zinc precursor and nitric oxide (NO) as the dopant. Characterization results, including resistivity, Hall measurements, photoluminescence, and SIMS, are reported and discussed. Electrical behavior was observed to be dependent on illumination, atmosphere, and heat treatment, especially for p-type material.

Geology and hydrothermal alteration at the Madh adh Dhahab epithermal precious-metal deposit, Kingdom of Saudi Arabia

Science.gov (United States)

Doebrich, J.L.; LeAnderson, J.P.

1984-01-01

Mahd adh Dhahab is a late Precambrian epithermal gold-silver-base metal deposit located in the west-central part of the Arabian Shield. North-trending quartz veins containing base and precious metals cut an east-striking, north-dipping homoclinal sequence of volcanic, volcaniclastic, and epiclastic rocks of intermediate to felsic composition. Ore was localized where the veins cut competent, coarse-grained, fragmental units directly below incompetent and impermeable tuff units. The proximity of an epizonal rhyolite porphyry stock to these contacts also was important in localizing ore. Ore minerals include native gold and silver, gold-silver tellurides, chalcopyrite, sphalerite, and minor galena, and five stages of mineralization have been identified.

Deposition and characterization of noble metal onto surfaces of 304l stainless steel

International Nuclear Information System (INIS)

Contreras R, A.; Arganis J, C. R.; Aguilar T, J. A.; Medina A, A. L.

2010-10-01

Noble metal chemical addition (NMCA) plus hydrogen water chemistry is an industry-wide accepted approach for potential intergranular stress corrosion cracking mitigation of BWR internals components. NMCA is a method of applying noble metal onto BWR internals surfaces using reactor water as the transport medium that causes the deposition of noble metal from the liquid onto surfaces. In this work different platinum concentration solutions were deposited onto pre-oxidized surfaces of 304l steel at 180 C during 48 hr in an autoclave. In order to simulate the zinc water conditions, deposits of Zn and Pt-Zn were also carried out. The solutions used to obtain the deposits were: sodium hexahydroxyplatinate (IV), zinc nitrate hydrate and zinc oxide. The deposits obtained were characterized by scanning electron microscopy and X-ray diffraction. Finally, the electrochemical corrosion potential of pre-oxidized samples with Pt deposit were obtained and compared with the electrochemical corrosion potential of only pre-oxidized samples. (Author)

Structural characterization of chemically deposited PbS thin films

International Nuclear Information System (INIS)

Fernandez-Lima, F.A.; Gonzalez-Alfaro, Y.; Larramendi, E.M.; Fonseca Filho, H.D.; Maia da Costa, M.E.H.; Freire, F.L.; Prioli, R.; Avillez, R.R. de; Silveira, E.F. da; Calzadilla, O.; Melo, O. de; Pedrero, E.; Hernandez, E.

2007-01-01

Polycrystalline thin films of lead sulfide (PbS) grown using substrate colloidal coating chemical bath depositions were characterized by RBS, XPS, AFM and GIXRD techniques. The films were grown on glass substrates previously coated with PbS colloidal particles in a polyvinyl alcohol solution. The PbS films obtained with the inclusion of the polymer showed non-oxygen-containing organic contamination. All samples maintained the Pb:S 1:1 stoichiometry throughout the film. The amount of effective nucleation centers and the mean grain size have being controlled by the substrate colloidal coating. The analysis of the polycrystalline PbS films showed that a preferable (1 0 0) lattice plane orientation parallel to the substrate surface can be obtained using a substrate colloidal coating chemical bath deposition, and the orientation increases when a layer of colloid is initially dried on the substrate

Electroless deposition and electrical characterization of N- Cu 2 O ...

African Journals Online (AJOL)

This work describes the preparation of n-Cu2O layer by the electroless methods of boiling and immersion of copper plates in 0.001M CuSO4Electron Microscopy (SEM) have been used to characterize the oxide films deposited. XRD studies show, for the first time, that cuprous oxide (Cu2O) and cupric oxide (CuO) were ...

Structural characterization of ZnO thin films grown on various substrates by pulsed laser deposition

International Nuclear Information System (INIS)

Novotný, M; Bulíř, J; Lančok, J; Čížek, J; Kužel, R; Connolly, J; McCarthy, E; Krishnamurthy, S; Mosnier, J-P; Anwand, W; Brauer, G

2012-01-01

ZnO thin films were grown by pulsed laser deposition on three different substrates: sapphire (0 0 0 1), MgO (1 0 0) and fused silica (FS). The structure and morphology of the films were characterized by x-ray diffraction and scanning electron microscopy and defect studies were carried out using slow positron implantation spectroscopy (SPIS). Films deposited on all substrates studied in this work exhibit the wurtzite ZnO structure and are characterized by an average crystallite size of 20-100 nm. However, strong differences in the microstructure of films deposited on various substrates were found. The ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit local epitaxy, i.e. a well-defined relation between film crystallites and the substrate. Domains with different orientation relationships with the substrate were found in both films. On the other hand, the film deposited on the FS substrate exhibits fibre texture with random lateral orientation of crystallites. Extremely high compressive in-plane stress of σ ∼ 14 GPa was determined in the film deposited on the MgO substrate, while the film deposited on sapphire is virtually stress-free, and the film deposited on the FS substrate exhibits a tensile in-plane stress of σ ∼ 0.9 GPa. SPIS investigations revealed that the concentration of open-volume defects in the ZnO films is substantially higher than that in a bulk ZnO single crystal. Moreover, the ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit a significantly higher density of defects than the film deposited on the amorphous FS substrate. (paper)

PREPARATION AND CHARACTERIZATION OF IRON SULPHIDE THIN FILMS BY CHEMICAL BATH DEPOSITION METHOD

Directory of Open Access Journals (Sweden)

Anuar Kassim

2010-06-01

Full Text Available FeS2 thin films have been deposited by using low cost chemical bath deposition technique. The films obtained under deposition parameters such as bath temperature (90 °C, deposition period (90 min, electrolyte concentration (0.15 M and pH of the reactive mixture (pH 2.5. The thin films were characterized using X-ray diffraction and atomic force microscopy in order to study the structural and morphological properties. The band gap energy, transition type and absorption properties were determined using UV-Vis Spectrophotometer. X-ray diffraction displayed a pattern consistent with the formation of an orthorhombic structure, with a strong (110 preferred orientation. Atomic force microscopy image showed the substrate surface is well covered with irregular grains. A direct band gap of 1.85 eV was obtained according to optical absorption studies.   Keywords: Iron sulfide, X-ray diffraction, chemical bath deposition, thin films

Hydrothermal deposition and characterization of silicon oxide nanospheres

International Nuclear Information System (INIS)

Pei, L.Z.

2008-01-01

Silicon oxide nanospheres with the average diameter of about 100 nm have been synthesized by hydrothermal deposition process using silicon and silica as the starting materials. The silicon oxide nanospheres were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectrum, respectively. The results show that large scale silicon oxide nanospheres with the uniform size are composed of Si and O showing the amorphous structure. Strong PL peak at 435 nm is observed demonstrating the good blue light emission property

Understanding the History of a Diverse Inverted Landscape: Summary and Plan for Finishing the 1:500k Geologic Map of Aeolis Dorsa, Mars

Science.gov (United States)

Jacobsen, R. E.; Burr, D. M.; Peel, S. E.; Borden, R. M.; Boyd, A. S.

2018-06-01

The Aeolis Dorsa region, Mars, consists of highlands and transitional units of the late Noachian, and aeolian/volcaniclastic deposits interleaved with fluvial and lacustrine deposits formed during the Hesperian and Amazonian periods.

Catahoula formation as a source of sedimentary uranium deposits in east Texas

International Nuclear Information System (INIS)

Ledger, E.B.; Tieh, T.T.

1983-01-01

Volcanic glass-rich mudstone and siltstone samples from the Oligocene/Miocene Catahoula formation of Jasper County, Texas, and coeval volcaniclastic rock samples from Trans-Pecos, Texas, have been compared as to U, Th, Zr, Ti, K, Rb, and Sr contents. Uranium is slightly greater in the distal ash (5.85 ppM U) compared to the Trans-Pecos samples (average 5.41 ppM U). Diagenetic and pedogenetic alteration of Catahoula volcanic glass releases uranium to solution and, under favorable conditions, this uranium may accumulate to form ore bodies. Uranium has been produced from such ore bodies in south Texas, but economic deposits are not known in east Texas. Significant differences between south and east Texas include: (1) a greater amount of volcanic debris delivered to south Texas, both as air-fall ash and stream-transported material, (2) delivery of only air-fill ash to east Texas, (3) the possibility of more petroleum-related reductants such as H 2 S in south Texas, and (4) pervasive glass alteration with subsequent uranium release in south Texas due to late calichification. These differences argue against economic deposits of the south Texas type being found in east Texas. If economic deposits occur they are likely to be far downdip making exploration difficult and expensive

Physics of enriched uranyl fluoride deposit characterizations using active neutron and gamma interrogation techniques with 252Cf

International Nuclear Information System (INIS)

Wyatt, M.S.; Hannon, T.F.

1998-01-01

A method was developed and successfully applied to characterize large uranyl fluoride (UO 2 F 21 ) deposits at the former Oak Ridge Gaseous Diffusion Plant. These deposits were formed by a wet air in-leakage into the UF 6 process gas lines over a period of years. The resulting UO 2 F 2 is hygroscopic, readily absorbing moisture from the air to form hydrates as UO 2 F 2 -nH 2 O. The ratio of hydrogen to uranium, denoted H/U, can vary from 0--16, and has significant nuclear criticality safety impacts for large deposits. In order to properly formulate the required course of action, a non-intrusive characterization of the distribution of the fissile material within the pipe, its total mass, and amount of hydration was needed. The Nuclear Weapons Identification System (NWIS) previously developed at the Oak Ridge Y-12 Plant for identification of uranium weapons components in storage containers was used to successfully characterize the distribution, hydration, and total mass of these deposits

Characterization of Deposited Platinum Contacts onto Discrete Graphene Flakes for Electrical Devices

KAUST Repository

Holguin Lerma, Jorge A.

2016-05-03

For years, electron beam induced deposition has been used to fabricate electrical contacts for micro and nanostructures. The role of the contact resistance is key to achieve high performance and efficiency in electrical devices. The present thesis reports on the electrical, structural and chemical characterization of electron beam deposited platinum electrodes that are exposed to different steps of thermal annealing and how they are used in four-probe devices of ultrathin graphite (uG) flakes (<100nm thickness). The device integration of liquid phase exfoliated uG is demonstrated, and its performance compared to devices made with analogous mechanically exfoliated uG. For both devices, similar contact resistances of ~2kΩ were obtained. The electrical measurements confirm a 99.5% reduction in contact resistance after vacuum thermal annealing at 300 °C. Parallel to this, Raman characterization confirms the formation of a nanocrystalline carbon structure over the electrode. While this could suggest an enhancement of the electrical transport in the device, an additional thermal annealing step in air at 300 °C, promoted the oxidation and removal of the carbon shell and confirmed that the contact resistance remained the same. Overall this shows that the carbon shell along the electrode has no significant role in the contact resistance. Finally, the challenges based on topographical analysis of the deposited electrodes are discussed. Reduction of the electrode’s height down to one-third of the initial value, increased surface roughness, formation of voids along the electrodes and the onset of platinum nanoparticles near the area of deposition, represent a challenge for future work.

The Chahnaly low sulfidation epithermal gold deposit, western Makran volcanic arc, southeastern Iran

Science.gov (United States)

Sholeh, Ali; Rastad, Ebrahim; Huston, David L.; Gemmell, J. Bruce; Taylor, Ryan D.

2016-01-01

The Chahnaly low-sulfidation epithermal Au deposit and nearby Au prospects are located northwest of the intermittently active Bazman stratovolcano on the western end of the Makran volcanic arc, which formed as the result of subduction of the remnant Neo-Tethyan oceanic crust beneath the Lut block. The arc hosts the Siah Jangal epithermal and Kharestan porphyry prospects, near Taftan volcano, as well as the Saindak Cu-Au porphyry deposit and world-class Reko Diq Cu-Au porphyry deposit, near Koh-i-Sultan volcano to the east-northeast in Pakistan. The host rocks for the Chahnaly deposit include early Miocene andesite and andesitic volcaniclastic rocks that are intruded by younger dacitic domes. Unaltered late Miocene dacitic ignimbrites overlie these rocks. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data yield ages between 21.8 and 9.9 Ma for the acidic-intermediate regional volcanism. The most recent volcanic activity of the Bazman stratovolcano involved extrusion of an olivine basalt during Pliocene to Quaternary times. Interpretation of geochemical data indicate that the volcanic rocks are synsubduction and calc-alkaline to subalkaline. The lack of a significant negative Eu anomaly, a listric-shaped rare earth element pattern, and moderate La/Yb ratios of host suites indicate a high water content of the source magma.

Paleoecology, stratigraphy and sedimentology of the deposit of diatomite Loma Camastro, Liberia-Guanacaste

International Nuclear Information System (INIS)

Gamboa-Sojo, Viviana

2013-01-01

The use of fossil diatoms have sought to establish the evolution of the paleoecological and sedimentary processes, a section of paleolake in the warehouse Loma Camacho, Liberia-Guanacaste. The same has consisted of a volcano-sedimentary sequence of continental origin, shown as a lacustrine deposit, due to the presence of diatoms as their predominant fossil feature. The stratigraphy and sedimentology are established in detail of a portion of the formation of the Loma indicating, by this analysis, materials reworked of volcaniclastic origin and sedimentary deposits of lacustrine origin. The study has coincided to a sequence of tobitas, differentiated by their granulometry, microscopically corresponded to lodolites or claystones, with concentrations different of diatom fossils and crystals (predominantly quartz and biotic), in a clay matrix. Patterns of variation in the diatom paleocommunities are determined and have been recognized different species. General environmental conditions of paleolake are established, such as pH, productivity, solar radiation, salinity, etc. In addition, changes in diatom communities, sedimentation patterns and relations to the local and regional context were correlated setting dominant paleoenvironmental conditions for that depositional period in Loma Camastro. The main influence has been the seasonal changes in dry and rainy periods and constant volcanic activity of Volcan Rincon de la Vieja [es

Seismic refraction technique aplications in the geotechnical characterization of the Cachoeira deposit massif, Caetite, State of Bahia, Brazil

International Nuclear Information System (INIS)

Malagutti Filho, W.; Oliveira Braga, T. de.

1984-01-01

Geophysical surveys throught the Cachoeira Uranium deposit massif were carried out with the purpose of assisting in the geotechnical characterization for the implantation of the Mining-Industrial Complex projects on the Lagoa Real uranium deposits, Caetite municipality, state of Bahia, Brazil. This study discusses the methodology utilized in the geophysical surveys and their results as well as their applications to the geotechnical characterization as a whole. (D.J.M.) [pt

Microstructure Related Characterization of a-Si:H Thin Films PECVD Deposited under Varied Hydrogen Dilution

Directory of Open Access Journals (Sweden)

Veronika Vavrunkova

2007-01-01

Full Text Available We report on the structure and optical properties of hydrogenated silicon thin films deposited by plasma - enhanced chemical vapor deposition (PECVD from silane diluted with hydrogen in a wide dilution range. The samples deposited with dilutions below 30 were detected as amorphous hydrogenated silicon (a-Si:H with crystalline grains of several nanometers in size which represent the medium-range order of a-Si:H. The optical characterization confirmed increasing ordering with the increasing dilution. The optical band gap was observed to be increasing function of the dilution.

Characterization of chemically deposited Ag/sub 2/S thin films

International Nuclear Information System (INIS)

Choudhury, M.G.M.; Rahman, M.M; Shahjahan, M.; Hossain, M.S.; Muhibbullah, M.; Uddin, M.A.; Banu, D.A.

2001-01-01

Silver Sulphide (Ag/sub 2/S) thin films were prepared by the chemical deposition method on glass substrates. Films of different thickness were deposited at room temperature. The films obtained were found to the uniform, pin-hole free and strongly adherent to the substrates. Films were characterized by X-$D, Hall effect, dc conductivity, thermoelectric power and optical measurements. X-RD revealed that as deposited films are amorphous with some microcrystalline structure. Hall effect measurement shows that the material deposited is n-type semiconductor with carrier concentration of the order of 10/sup 14/ cm/sup -3/. The dc dark conductivity shows two distinct conduction regions. The conductivity increases quite sharply above a transition temperature. Tt and below Tt the conductivity is weakly activated process with hopping via localized states. Above Tt the activation energy is quite high and the conduction may be due to impurity states to extended states. From the nature of variation of thermoelectric power with temperature it was found that in this material the position of Fermi level lie above the conduction band for thicker films and below the conduction band for relatively thinner films. The optical band gap of the films has been calculated from the transmittance spectra. The evaluated optical band gap E/sup opt/ was found to be about 1.1 eV and the value do not change much with film thickness. The refractive index, extinction coefficient and dielectric constants have also been evaluated from the transmission measurements. (author)

Deposition and characterization of ZnS thin films using chemical bath deposition method in the presence of sodium tartrate as complexing agent

International Nuclear Information System (INIS)

Kassim, A.; Tee, T.W.; Min, H.S.; Nagalingam, S.

2011-01-01

ZnS thin films were deposited on indium tin oxide glass substrate using the chemical bath deposition method. The deposited films were characterized by X-ray diffraction and atomic force microscopy. The influence of bath temperature on the structure and morphology of the thin films was investigated at three different bath temperatures of 60, 70 and 80 deg. C in the presence of sodium tartrate as a complexing agent. The XRD results indicated that the deposited ZnS thin films exhibited a polycrystalline cubic structure. The number of ZnS peaks increased from three to four peaks as the bath temperature was increased from 60 to 80 deg. C based on the XRD patterns. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the bath temperature. The grain size increased as the bath temperature was increased from 60 to 80 deg. C. (author)

Deposition and characterization of TaAIN thin films by reactive magnetron sputtering

International Nuclear Information System (INIS)

Oliveira, G.B.; Fernandez, D.R.; Fontes Junior, A.S.; Felix, L.C.; Tentardini, E.K.; Silva Junior, A.H. da

2016-01-01

Phase stability, oxidation resistance and great mechanical properties are the main objectives when synthesizing protective coatings. The tantalum nitride (TaN) has aroused interest because of its high temperature stability, chemical inertness and thermal conductivity. However, it has a low hardness value when compared to other coatings. Researches has shown that one way to improvements in the properties of a thin film is by adding other elements in the deposition process. Therefore, the objective of this study was to deposit thin films of TaAlN by magnetron sputtering, changing the aluminum concentration of 2, 5, 7, to 14%. Then the coatings were characterized by EDS, RBS, GIXRD and nanohardness. In this study was found that the aluminum deposited did not change the oxidation resistance of the coating, and the highest value of hardness was 28 GPa for the sample with 14 at.%. (author)

Electron microscopy characterization of Ni-Cr-B-Si-C laser deposited coatings.

Science.gov (United States)

Hemmati, I; Rao, J C; Ocelík, V; De Hosson, J Th M

2013-02-01

During laser deposition of Ni-Cr-B-Si-C alloys with high amounts of Cr and B, various microstructures and phases can be generated from the same chemical composition that results in heterogeneous properties in the clad layer. In this study, the microstructure and phase constitution of a high-alloy Ni-Cr-B-Si-C coating deposited by laser cladding were analyzed by a combination of several microscopy characterization techniques including scanning electron microscopy in secondary and backscatter imaging modes, energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The combination of EDS and EBSD allowed unequivocal identification of micron-sized precipitates as polycrystalline orthorhombic CrB, single crystal tetragonal Cr5B3, and single crystal hexagonal Cr7C3. In addition, TEM characterization showed various equilibrium and metastable Ni-B, Ni-Si, and Ni-Si-B eutectic products in the alloy matrix. The findings of this study can be used to explain the phase formation reactions and to tune the microstructure of Ni-Cr-B-Si-C coatings to obtain the desired properties.

Fluid Inclusion Study of The Tumpangpitu High Sulfidation Epithermal Gold Deposit in Banyuwangi District, East Java, Indonesia

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Yu Yu Myaing

2018-03-01

Full Text Available The Tumpangpitu high sulfidation (HS epithermal gold deposit is located in the south coast of East Java, Banyuwangi District, East Java Province, Indonesia. This area lies within the central portion of the Cenozoic Sunda‐Banda magmatic arc which trends southeast from northern Sumatra to west Java then eastward through east Java, Bali, Lombok, Sumbawa and terminating at Banda sea. The geology of the Tumpangpitu is predominantly occupied by Late Oligocene to Middle Miocene low-K calc-alkaline to alkaline andesitic volcanic rocks and interbedded with volcaniclastic rock sequences, which are associated with low-K intermediate intrusions. The mineralization style at the Tumpangpitu area is composed of a high‐sulfidation (HS epithermal gold-copper system which is typically associated with concealed gold-rich porphyry copper system. The HS epithermal mineralization is hosted by volcanic and volcaniclastic rocks in this research area. The mineralization domains are divided into Zone A, Zone B and Zone C which are situated along NW-SE-trending silica ledges zones. The HS epithermal mineralization is texturally occurs as vuggy replacements mineralization as well as stockworks, disseminated forms, fractures and veins. Fluid inclusion study was conducted for 6 quartz vein samples which petrographically entrapped fluid inclusions. Homogenization temperature (Th and melting temperature (Tm can microthermometrically be determined by fluid inclusion analysis. The average homogenization temperature (Th of the fluid inclusions gives 180˚C to 342˚C and melting temperature are from -0.1 ˚C to -1.4˚C. Tm corresponds to the salinities ranging from 0.1 to 4.5 wt% NaCl equivalent. The paleodepth of ore formation can be estimated from the salinity of fluid. Since the deposit was not formed at boiling condition, the minimum paleodepth of ore (quartz samples taken from both shallow level (53.35 m and deep level (135.15 m is determined at 650m and 1,220 m

Deposition and characterization of aluminum magnesium boride thin film coatings

Science.gov (United States)

Tian, Yun

Boron-rich borides are a special group of materials possessing complex structures typically comprised of B12 icosahedra. All of the boron-rich borides sharing this common structural unit exhibit a variety of exceptional physical and electrical properties. In this work, a new ternary boride compound AlMgB14, which has been extensively studied in bulk form due to its novel mechanical properties, was fabricated into thin film coatings by pulsed laser deposition (PLD) technology. The effect of processing conditions (laser operating modes, vacuum level, substrate temperature, and postannealing, etc.) on the composition, microstructure evolution, chemical bonding, and surface morphology of AlMgB14 thin film coatings has been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectrometry; the mechanical, electrical, and optical properties of AlMgB14 thin films have been characterized by nanoindentation, four-point probe, van der Pauw Hall measurement, activation energy measurement, and UV-VIS-NIR spectrophotometer. Experimental results show that AlMgB14 films deposited in the temperature range of 300 K - 873 K are amorphous. Depositions under a low vacuum level (5 x 10-5 Torr) can introduce a significant amount of C and O impurities into AlMgB14 films and lead to a complex oxide glass structure. Orthorhombic AlMgB14 phase cannot be obtained by subsequent high temperature annealing. By contrast, the orthorhombic AlMgB 14 crystal structure can be attained via high temperature-annealing of AlMgB14 films deposited under a high vacuum level (boride films, high vacuum level-as deposited AlMgB14 films also possess a low n-type electrical resistivity, which is a consequence of high carrier concentration and moderate carrier mobility. The operative electrical transport mechanism and doping behavior for high vacuum level-as deposited AlMgB14

Deposition and Characterization of Silver Oxide from Solution of Silver, Cassava and Sugarcane Juice Effects

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Uche E. Ekpunobi

2013-06-01

Full Text Available Silver oxide was deposited on metallic substrates (zinc and lead from silver solution with different additives at a pH of 5, dc current of 0.2A, 4V for 20seconds at 25°C. The additives were cassava solution and sugarcane juice. The metallic substrates served as cathode while a copper electrode serves as the anode. Compositions of the electrolytes were 50ml AgNO3, 50ml AgNO3 and 50ml of cassava solution or 50ml of sugarcane juice. Structural and textural characterizations were carried out on the deposits. The result showed that deposition using zinc substrate gave a better result than that of lead in that the deposits were pure without impurities. Using cassava solution as additive, a pure Ag2O3 deposit was obtained while sugarcane juice gave a pure intergrowth of Ag2O3 and Ag3O4 deposits both on zinc substrates.

NEOGENE STRATIGRAPHY OF THE İZMİR -OUTER- BAY ISLANDS

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Fikret GÖKTAŞ

2016-12-01

Full Text Available The volcaniclastics, derived from calcalkaline acidic-intermediate volcanism in the region during late Early Miocene, and lacustrine deposits of Middle Miocene and alkaline volcanics are exposed on Uzun Ada , Hekim Adası, Çiçek Adası and Karantina Adası  in the Outer Gulf of Izmir.Kocadağ volcaniclastics derived from Kocadağ volcanism, by extruding mainly calcalkaline andesitic-dacitic products during Late Early Miocene, represents the exposed oldest rock unit. The volcaniclastic succession extending in the north of Uzun Ada is composed of pyroclastics in ignimbrite and blocky ash flow facieses, and epiclastics in volcanic mass flow (lahar facies. Foça tuff, represented by rhyolitic ignimbrites, originated from an area around Foça and moving to an area around Uzun Ada, emplaced onto the Kocadağ volcaniclastics in two main explosive stages. The Değirmentepe Member alluvial deposits composed of coarse volcanic detritus were deposited during a inactive period between the explosion stages.  A K/Ar age of 16.0 Ma was obtained from a rhyolite dome, which shows lateral relationship with the correlant ignimbrites in Foça Peninsula, and so it is considered that Foça tuff emplaced onto the region at the end of late Early Miocene.Lacustrine-dominated Middle Miocene succession, which overlies the Foça tuff unconformably, differentiated as the Urla group. Urla group consists of alluvial Beşiktepe Formation, the Pırnallı island  volcaniclastics, which is composed of sublacustrine volcanic density-flow deposits and felsic ignimbrites, Hekim Adası basalt comprising basic volcanics and lacustrine Urla limestone, respectively from bottom to top. Beşiktepe Formation only exposed on Uzun Ada, overlies the Foça tuff with an unconformity indicating a basin margin deposition during the Middle Miocene. Pırnallı island volcaniclastic succession, which its lower boundary does not expose within the area on Hekim Adası and Çiçek Adaları, is

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

Energy Technology Data Exchange (ETDEWEB)

Blanda, Giuseppe [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Piazza, Salvatore; Sunseri, Carmelo [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Inguanta, Rosalinda, E-mail: rosalinda.inguanta@unipa.it [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

2016-07-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO{sub 4}·H{sub 2}O; HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO{sub 3}){sub 2}·4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

International Nuclear Information System (INIS)

Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

2016-01-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO_4·H_2O; HA, Ca_1_0(PO_4)_6(OH)_2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO_3)_2·4H_2O and NH_4H_2PO_4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel.

Science.gov (United States)

Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

2016-07-01

In this work, brushite and brushite/hydroxyapatite (BS, CaHPO4·H2O; HA, Ca10(PO4)6(OH)2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO3)2·4H2O and NH4H2PO4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50°C for all deposition times, while at 25°C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Ash turbidites from Southern Italy help understanding the parent eruptions and contributing to geodynamic evolution cadre of the Tyrrhenian sea

Science.gov (United States)

Doronzo, Domenico Maria

2010-05-01

Tephra layers intercalated in sedimentary successions are very interesting since they represent some instants of geodynamic evolution in a sedimentation basin. Furthermore, they can constitute deposits of explosive eruptions whose distal behaviour can be useful for studying the volcanoes activity, especially when pyroclastic deposits in proximal areas are absent. In the Craco area (Matera, Italy), thick ash turbidites intercalated in marine clays deposits have been recently recognized, which interest is related to the considerable cropping out thickness (1 to 5 m), freshness of the material and absence of sedimentary component. Petrography, sedimentology and chemistry of the deposits have been characterized with the aim of defining genesis and deposition of the material. The deposits are essentially made up of ashy pyroclasts, dominated by fresh acidic to intermediate glass, mostly in the form of shards, pumice fragments and groundmass fragments with vitrophyric texture. Rare crystals include Pl, Opx, Cpx, Hbl and Bt. 40Ar/39Ar geochronology on the amphibole dated one level to 2.24 ± 0.06 Ma, indicating the Late Pliocene. The grain size (fine ash) and textural features of the deposits are typical of pyroclastic fall deposits related to explosive eruptions with consequent upward projection of the fragmented material through Plinian columms. The columns turned eastward because of stratospheric winds and the material fell in a marine environment. It deposited on the slope of Pliocene basins in the frontal sector of the Southern Apennine chain. Structural features are the following: fining-upward gradation of the deposits with cross- and convolute laminations at the base and fine-grained massive beds at the top. They suggest that the primary pyroclastic fall deposits were mobilized as volcaniclastic turbidity currents towards a deeper environment. Glass and crystal compositions were investigated by SEM/EDS analysis. Petrographycal and chemical compositions of the

Microstructure, optical characterization and light induced degradation in a-Si:H deposited at different temperatures

International Nuclear Information System (INIS)

Minani, E.; Sigcau, Z.; Adgebite, O.; Ramukosi, F.L.; Ntsoane, T.P.; Harindintwari, S.; Knoesen, D.; Comrie, C.M.; Britton, D.T.; Haerting, M.

2006-01-01

The microstructure and optical properties of a series of hydrogenated amorphous silicon layers deposited on glass substrates at different temperature have been characterized by means of X-ray diffraction techniques and optical spectroscopy. The radial distribution function of the as-deposited samples showed an increase in the bond angle and a decrease in the radial distance indicating a relaxation of the amorphous network with increasing the deposition temperature. Light induced degradation was studied using a simulated daylight spectrum. The changes in hydrogen bonding configuration, associated with the light soaking at different stages of illumination, was monitored via the transmission bands of the vibrational wag and stretch modes of the IR spectrum

Characterization of CNT-MnO_2 nanocomposite by electrophoretic deposition as potential electrode for supercapacitor

International Nuclear Information System (INIS)

Darari, Alfin; Rismaningsih, Nurmanita; Ardiansah, Hafidh Rahman; Arifin,; Ningrum, Andini Novia; Subagio, Agus

2016-01-01

Energy crisis that occured in Indonesia suggests that energy supply could not offset the high rate request and needs an electric energy saving device which can save high voltage, safety, and unlimited lifetime. The weakness of batteries is durable but has a low power density while the capacitor has a high power density but it doesn’t durable. The renewal of this study is CNT-MnO_2 thin film fabrication method using electrophoretic deposition. Electrophoretic deposition is a newest method to deposited CNT using power supply with cheap, and make a good result. The result of FTIR analysis showed that the best CNT-MnO_2 composition is 75:25 and C-C bond is detected in fingerprint area. The result is electrode thin film homogen and characterized by X-ray diffraction (XRD) peaks 2θ=26,63° is characterization of graphite, and 2θ=43,97° is characterization of diamond Carbon type and measured by Scherrer formula results 52,3 nm material average size .EIS test results its capacitance about 7,86 F. from the data it can be concluded that CNT-MnO_2 potential electrode very promising for further study and has a potential to be a high capacitance, and fast charge supercapacitor which can be applied for electronic devices, energy converter, even electric car.

Conceptual design of a remote system for characterizing oilsands tailings deposits

Energy Technology Data Exchange (ETDEWEB)

Lipsett, M.G.; Rivard, B. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering; Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences

2010-07-01

This PowerPoint presentation described the design of a remote system for characterizing oil sands tailings deposits. The wheeled mobile robot technology was developed in order to improve the trafficability of composite tailings (CT) and other engineering tailings deposits, as well as to identify differences in feedstocks and process performance, and to determine shear strength losses from dynamic loading. The technology was comprised of a spectroscopy component, and a mobile robot equipped with surface measurement sensors. The control system included navigation and traction control devices. A communication component was also included. Tools used in the system included a penetrometer, a viscosimeter, and an automatic sample collection device. Tests have been conducted to determine the system's driving ability. Further tests are being conducted to evaluate the performance of the robot sensors and controllers. tabs., figs.

Revelation of graphene-Au for direct write deposition and characterization

Directory of Open Access Journals (Sweden)

Deepa Melepurath

2011-01-01

Full Text Available Abstract Graphene nanosheets were prepared using a modified Hummer's method, and Au-graphene nanocomposites were fabricated by in situ reduction of a gold salt. The as-produced graphene was characterized by X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy (HR-TEM. In particular, the HR-TEM demonstrated the layered crystallites of graphene with fringe spacing of about 0.32 nm in individual sheets and the ultrafine facetted structure of about 20 to 50 nm of Au particles in graphene composite. Scanning helium ion microscopy (HIM technique was employed to demonstrate direct write deposition on graphene by lettering with gaps down to 7 nm within the chamber of the microscope. Bare graphene and graphene-gold nanocomposites were further characterized in terms of their composition and optical and electrical properties.

The Shah-Ali-Beiglou Zn-Pb-Cu (-Ag Deposit, Iran: An Example of Intermediate Sulfidation Epithermal Type Mineralization

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Khadijeh Mikaeili

2018-04-01

Full Text Available The Shah-Ali-Beiglou epithermal base metal-silver deposit is located in the Tarom-Hashjin metallogenic province (THMP in northwestern Iran. This deposit is hosted by quartz monzonite dikes of Oligocene age and surrounded by andesite to trachyandesite volcanic and volcaniclastic rocks of Eocene age. The subvolcanic rocks in the study area vary in composition from quartz-monzonite to monzonite and have metaluminous, calc-alkaline to shoshonitic affinity. These rocks have I-type geochemical characteristic and are related to post-collisional tectonic setting. The mineralization occurs as NE-SW and E-W-trending brecciated veins controlled by strike-slip and normal faults, which are associated to the Late Oligocene compressional regime. The mineral paragenesis of the vein mineralization is subdivided into pre-ore stage, ore stage, post-ore stage, and supergene stage. Pre-ore stage is dominated by quartz, sericite, and subhedral to anhedral pyrite as disseminated form. Ore-stage is represented by quartz, sphalerite (from 0.1 mol % to 4 mol % FeS, galena, chalcopyrite, tetrahedrite-tennantite, minor seligmannite and enargite, as vein-veinlet, cement and clast breccias. Post-ore stage is defined by deposition of quartz and carbonate along with minor barite, and supergene stage is characterized by bornite, chalcocite, covellite, hematite, goethite, and jarosite. The ore mineralization is associated with the silicic alteration. The styles of alteration are silicic, carbonate, sericitic, chloritic, and propylitic. Fluid inclusions in sphalerite have a wide range of salinities between 0.35 wt % and 21.4 wt % NaCl equivalent and homogenization temperatures range from 123 to 320 °C. The isotopic values of sulfides vary from 2.8‰ to 6.7‰ suggesting a magmatic source for the sulfur. In the present study, based on geological setting, alteration style of the host and wall rocks, main textures, mineral assemblages, composition of ore minerals, and structural

Characterization of nanostructured photosensitive cadmium sulphide thin films grown by SILAR deposition technique

International Nuclear Information System (INIS)

Ubale, A.U.; Bargal, A.N.

2010-01-01

This paper reports the preparation of photosensitive nanostructured CdS thin films by successive ionic layer adsorption and reaction (SILAR) method at room temperature. To obtain good quality CdS thin films, preparative conditions such as concentration of cationic and anionic precursors, adsorption and rinsing time durations etc. are optimized. The structural, optical and electrical characterizations of the as-deposited and annealed CdS thin films were carried out using X-ray diffraction, scanning electron microscopy, optical absorption and electrical resistivity methods. The photoconductivity studies showed that the annealed films are more than that photosensitive. The TEP measurement shows that deposited films are of n-type. (author)

Sedimentary processes in modern and ancient oceanic arc settings: evidence from the Jurassic Talkeetna Formation of Alaska and the Mariana and Tonga Arcs, western Pacific

Science.gov (United States)

Draut, Amy E.; Clift, Peter D.

2006-01-01

Sediment deposited around oceanic volcanic ares potentially provides the most complete record of the tectonic and geochemical evolution of active margins. The use of such tectonic and geochemical records requires an accurate understanding of sedimentary dynamics in an arc setting: processes of deposition and reworking that affect the degree to which sediments represent the contemporaneous volcanism at the time of their deposition. We review evidence from the modern Mariana and Tonga arcs and the ancient arc crustal section in the Lower Jurassic Talkeetna Formation of south-central Alaska, and introduce new data from the Mariana Arc, to produce a conceptual model of volcaniclastic sedimentation processes in oceanic arc settings. All three arcs are interpreted to have formed in tectonically erosive margin settings, resulting in long-term extension and subsidence. Debris aprons composed of turbidites and debris flow deposits occur in the immediate vicinity of arc volcanoes, forming relatively continuous mass-wasted volcaniclastic records in abundant accommodation space. There is little erosion or reworking of old volcanic materials near the arc volcanic front. Tectonically generated topography in the forearc effectively blocks sediment flow from the volcanic front to the trench; although some canyons deliver sediment to the trench slope, most volcaniclastic sedimentation is limited to the area immediately around volcanic centers. Arc sedimentary sections in erosive plate margins can provide comprehensive records of volcanism and tectonism spanning arc may be best reconstructed from sediments of the debris aprons for intervals up to ~ 20 My but no longer, because subduction erosion causes migration of the forearc basin crust and its sedimentary cover toward the trench, where there is little volcaniclastic sedimentation and where older sediments are dissected and reworked along the trench slope.

In vitro characterization of hydroxyapatite layers deposited by APS and HVOF thermal spraying methods

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Radu Alexandru Roşu

2012-03-01

Full Text Available Titanium alloys are successfully used in medicine as implants due to their high mechanical properties and good biocompatibility. To improve implant osseointegration of titanium alloys, they are covered with hydroxyapatite because of its bioactive properties. Coating the implants with hydroxyapatite by thermal spraying, due to the temperatures developed during the deposition process, the structure can be degraded, leading to formation of secondary phases, such as TCP, TT CP, CaO. The paper presents the experimental results of hydroxyapatite layers deposition by two thermal spraying methods: Atmospheric Plasma Spraying (APS and High Velocity Oxy-Fuel (HVOF. The microstructure of the deposited layers is characterized by X-ray diffraction analysis and electronic microscopy. The bioactivity of the hydroxyapatite layers was investigated in Simulated Body Fluid (SBF by immersing the covered samples deposited by the two thermal spraying methods. In both cases the coatings did not present defects as cracks or microcracks. X-ray diffraction performed on hydroxyapatite deposited layers shows that the structure was strongly influenced by plasma jet temperature, the structure consisting mainly of TCP (Ca3PO42. The samples deposited by HVO F after immersing in SBF lead to formation of biological hydroxyapatite, certifying the good bioactivity of the coatings.

U-Pb dating of silicic lavas, sills and syneruptive resedimented volcaniclastic deposits of the Lower Devonian Crudine Group, Hill End Trough, New South Wales

International Nuclear Information System (INIS)

Jagodzinski, E.A.; Black, L.P.

1999-01-01

The Hill End Trough of central-western New South Wales was an elongate deep marine basin that existed in the Lachlan Fold Belt from the early Late Silurian to late Early Devonian. It is represented by a regionally extensive. unfossiliferous sequence of interbedded turbidites and hemipelagites of substantially silicic Volcanic derivation, which passes laterally into contemporaneous shallow-water sedimentary rocks. The Turondale and Merrions Formations of the Lower Devonian Crudine Group are two prominent volcanogenic formations in the predominantly sedimentary trough sequence. They contain a range of primary and resedimented volcanic facies suitable for U-Pb dating. These include widespread subaqueous silicic lavas and/or lava cryptodomes. and thick sequences of crystal-rich volcaniclastic sandstone emplaced by a succession of muss-flows that were generated by interaction between contemporaneous subaerial pyroclastic flows and the sea. Ion microprobe dating of the two volcanogenic formations by means of the commonly used SL 13 zircon standard yields ages ranging between 411.3 ± 5.1 and 404.8 ± 4.8 Ma. Normalising the data against a different zircon standard (QGNG) yields preferred slightly older mean ages that range between 413.4 ± 6.6 and 407.1 ± 6.9 Ma. These ages broadly approximate the Early Devonian age that has been historically associated with the Crudine Group. However, the biostratigraphically inferred late Lochkovian - early Emsian (mid-Early Devonian) age for the Merrions Formation is inconsistent with the current Australian Phunerozoic Timescale, which assigns an age of 410 Ma to the Silurian-Devonian boundary, and ages of 404.5 Ma and 395.5 Ma to the base and top of the Pragian, respectively. There is, however, good agreement if the new ages are compared with the most recently published revision of the Devonian time-scale. This suggests that the Early Devonian stage boundaries of the Australian Phanerozoic Timescale need to be revised downward. The

Properties and electric characterizations of tetraethyl orthosilicate-based plasma enhanced chemical vapor deposition oxide film deposited at 400 °C for through silicon via application

International Nuclear Information System (INIS)

Su, Meiying; Yu, Daquan; Liu, Yijun; Wan, Lixi; Song, Chongshen; Dai, Fengwei; Xue, Kai; Jing, Xiangmeng; Guidotti, Daniel

2014-01-01

The dielectric via liner of through silicon vias was deposited at 400 °C using a tetraethyl orthosilicate (TEOS)-based plasma enhanced chemical vapor deposition process in a via-middle integration scheme. The morphology, conformality and chemical compositions of the liner film were characterized using field emission scanning electron microscopy and Fourier Transform Infrared spectroscopy. The thermal properties and electrical performance of blanket TEOS films were investigated by high temperature film stress and mercury probe Capacitance–Voltage measurements. The TEOS SiO 2 films show good conformality, excellent densification, low thermal stress, high breakdown voltage and low current leakage. - Highlights: • Tetraethyl orthosilicate-based oxide films were deposited for packaging application. • The oxide films deposited plasma-enhanced chemical vapor deposition (PECVD) at 400 °C. • The PECVD oxide films exhibit good step coverage. • The 400 °C PECVD oxide films exhibit low thermal stress and current leakage. • The 400 °C PECVD oxide films show high breakdown voltage and acceptable permittivity

Properties and electric characterizations of tetraethyl orthosilicate-based plasma enhanced chemical vapor deposition oxide film deposited at 400 °C for through silicon via application

Energy Technology Data Exchange (ETDEWEB)

Su, Meiying, E-mail: sumeiying@ime.ac.cn [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Yu, Daquan, E-mail: yudaquan@ime.ac.cn [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Jiangsu R and D Center for Internet of Things, Wuxi 214135 (China); Liu, Yijun [Piotech Co. Ltd, Shenyang 110179 (China); Wan, Lixi [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); Song, Chongshen; Dai, Fengwei [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Xue, Kai [National Center for Advanced Packaging, Wuxi 214135 (China); Jing, Xiangmeng [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China); National Center for Advanced Packaging, Wuxi 214135 (China); Guidotti, Daniel [Institute of Microelectronics of Chinese Academy of Sciences, Beijing 100029 (China)

2014-01-01

The dielectric via liner of through silicon vias was deposited at 400 °C using a tetraethyl orthosilicate (TEOS)-based plasma enhanced chemical vapor deposition process in a via-middle integration scheme. The morphology, conformality and chemical compositions of the liner film were characterized using field emission scanning electron microscopy and Fourier Transform Infrared spectroscopy. The thermal properties and electrical performance of blanket TEOS films were investigated by high temperature film stress and mercury probe Capacitance–Voltage measurements. The TEOS SiO{sub 2} films show good conformality, excellent densification, low thermal stress, high breakdown voltage and low current leakage. - Highlights: • Tetraethyl orthosilicate-based oxide films were deposited for packaging application. • The oxide films deposited plasma-enhanced chemical vapor deposition (PECVD) at 400 °C. • The PECVD oxide films exhibit good step coverage. • The 400 °C PECVD oxide films exhibit low thermal stress and current leakage. • The 400 °C PECVD oxide films show high breakdown voltage and acceptable permittivity.

Atmospheric particle characterization, distribution, and deposition in Xi'an, Shaanxi Province, Central China

International Nuclear Information System (INIS)

Cao Zongze; Yang Yuhua; Lu, Julia; Zhang Chengxiao

2011-01-01

Physical characterization and chemical analysis of settled dusts collected in Xi'an from November 2007 to December 2008 show that (1) dust deposition rates ranged from 14.6 to 350.4 g m -2 yr -1 . The average deposition rate (76.7 g m -2 yr -1 ) ranks the 11th out of 56 dust deposition rates observed throughout the world. The coal-burning power was the major particle source; (2) on average (except site 4), ∼10% of the settled dusts having size 70% having size <30 μm; (3) the concentrations for 20 out of 27 elements analyzed were upto 18 times higher than their soil background values in China. With such high deposition rates of dusts that contain elevated levels of toxic elements, actions should be taken to reduce emission and studies are needed to assess the potential impacts of settled particles on surface ecosystem, water resource, and human health in the area. - Research highlights: → High atmospheric dust deposition rate in Xi'an, Shaanxi, China. → Coal-burning power plan being a major source of particulate matter in Xi'an area. → High levels of toxic elements in the settled dusts. → Enrichment of heavy metals (e.g., Pb, Ni, Cu) in fine particles. - Atmospheric dust deposition rate is high and the levels of toxic elements associated with the settled dusts are elevated in Xi'an, Shaanxi, China.

Characterization for rbs of layers de grown cdznse for chemical deposition (cbd)

International Nuclear Information System (INIS)

Pedrero, E.; Larramendi, E.; Calzadilla, O.

1999-01-01

Depth and composition of CdZnSe thin films grown by Chemical Bath Deposition were characterized by Rutherford Backscattering Spectrometry. Depth and the relative cuantitity of Se, both decrease when annealed in air. The films have a non-stoichiometric Cd:Zn:Se composition constant from the substrate to the surface , with vacancies of Se. After annealing all the films come up to a similar composition: Cd( Zn 0.2 )Se

Characterization of the electrochemical behavior of coating by steel welding 308l and in presence of noble metals deposits

International Nuclear Information System (INIS)

Piedras, P.; Arganis J, C. R.

2014-10-01

In this work the oxide deposits and noble metals deposit were characterized (Ag and Pt) on a coating of stainless steel 308l that were deposited by the shield metal arc welding (SMAW) on steel A36 by means of scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. The extrapolation of Tafel technique was also used to obtain the corrosion potential (Ec) for the pre-rusty steel and for the samples with deposits of Pt and Ag under conditions of hydrogen water chemistry (HWC), demonstrating that this parameter diminishes with the presence of this deposits. (Author)

Gravity-Driven Deposits in an Active Margin (Ionian Sea) Over the Last 330,000 Years

Science.gov (United States)

Köng, Eléonore; Zaragosi, Sébastien; Schneider, Jean-Luc; Garlan, Thierry; Bachèlery, Patrick; Sabine, Marjolaine; San Pedro, Laurine

2017-11-01

In the Ionian Sea, the subduction of the Nubia plate underneath the Eurasia plate leads to an important sediment remobilization on the Calabrian Arc and the Mediterranean Ridge. These events are often associated with earthquakes and tsunamis. In this study, we analyze gravity-driven deposits in order to establish their recurrence time on the Calabrian Arc and the western Mediterranean Ridge. Four gravity cores collected on ridges and slope basins of accretionary prisms record turbidites, megaturbidites, slumping and micro-faults over the last 330,000 years. These turbidites were dated by correlation with a hemipelagic core with a multi-proxy approach: radiometric dating, δ18O, b* colour curve, sapropels and tephrochronology. The origin of the gravity-driven deposits was studied with a sedimentary approach: grain-size, lithology, thin section, geochemistry of volcanic glass. The results suggest three periods of presence/absence of gravity-driven deposits: a first on the western lobe of the Calabrian Arc between 330,000 and 250,000 years, a second between 120,000 years and present day on the eastern lobe of the Calabrian Arc and over the last 60,000 years on the western lobe, and a third on the Mediterranean Ridge over the last 37,000 years. Return times for gravity-driven deposits are around 1,000 years during the most important record periods. The turbidite activity also highlights the presence of volcaniclastic turbidites that seems to be link to the Etna changing morphology over the last 320,000 years.

Characterization of CNT-MnO{sub 2} nanocomposite by electrophoretic deposition as potential electrode for supercapacitor

Energy Technology Data Exchange (ETDEWEB)

Darari, Alfin, E-mail: alfindarari@st.fisika.undip.ac.id [Physics Department, Science and Mathematics Faculty, Diponegoro University (Indonesia); Rismaningsih, Nurmanita [Chemistry Department, Science and Mathematics Faculty, Diponegoro University (Indonesia); Ardiansah, Hafidh Rahman; Arifin,; Ningrum, Andini Novia; Subagio, Agus, E-mail: agus-fadhil@yahoo.com

2016-04-19

Energy crisis that occured in Indonesia suggests that energy supply could not offset the high rate request and needs an electric energy saving device which can save high voltage, safety, and unlimited lifetime. The weakness of batteries is durable but has a low power density while the capacitor has a high power density but it doesn’t durable. The renewal of this study is CNT-MnO{sub 2} thin film fabrication method using electrophoretic deposition. Electrophoretic deposition is a newest method to deposited CNT using power supply with cheap, and make a good result. The result of FTIR analysis showed that the best CNT-MnO{sub 2} composition is 75:25 and C-C bond is detected in fingerprint area. The result is electrode thin film homogen and characterized by X-ray diffraction (XRD) peaks 2θ=26,63° is characterization of graphite, and 2θ=43,97° is characterization of diamond Carbon type and measured by Scherrer formula results 52,3 nm material average size .EIS test results its capacitance about 7,86 F. from the data it can be concluded that CNT-MnO{sub 2} potential electrode very promising for further study and has a potential to be a high capacitance, and fast charge supercapacitor which can be applied for electronic devices, energy converter, even electric car.

Characterization and device applications of ZnO films deposited by high power impulse magnetron sputtering (HiPIMS)

Science.gov (United States)

Partridge, J. G.; Mayes, E. L. H.; McDougall, N. L.; Bilek, M. M. M.; McCulloch, D. G.

2013-04-01

ZnO films have been reactively deposited on sapphire substrates at 300 °C using a high impulse power magnetron sputtering deposition system and characterized structurally, optically and electronically. The unintentionally doped n-type ZnO films exhibit high transparency, moderate carrier concentration (˜5 × 1018 cm-3) and a Hall mobility of 8.0 cm2 V-1 s-1, making them suitable for electronic device applications. Pt/ZnO Schottky diodes formed on the HiPIMS deposited ZnO exhibited rectification ratios up to 104 at ±2 V and sensitivity to UV light.

Characterization of an enriched uranyl fluoride deposit in a valve and pipe intersection using time-of-flight transmission measurements with 252Cf

International Nuclear Information System (INIS)

Wyatt, M.S.; Hannon, T.F.

1998-01-01

A method was developed and successfully applied to characterize large uranyl fluoride (UO 2 F 2 ) deposits at the former Oak Ridge Gaseous Diffusion Plant. These deposits were formed by a wet air in-leakage into the UF 6 process gas lines over a period of years. The resulting UO 2 F 2 is hygroscopic, readily absorbing moisture from the air to form hydrates as UO 2 F 2 -nH 2 O. The ratio of hydrogen to uranium can vary from 0--16, and has significant nuclear criticality safety impacts for large deposits. In order to properly formulate the required course of action, a non-intrusive characterization of the distribution of the fissile material within the pipe, its total mass, and amount of hydration was necessary. The Nuclear Weapons Identification System (NWIS) previously developed at the Oak Ridge Y-12 Plant for identification of uranium weapons components in storage containers was used to successfully characterize these deposits

Just passing through --- high Hg deposition to Puerto Rico forest moves quickly off the landscape

Science.gov (United States)

Shanley, J. B.; Willenbring, J. K.; Kaste, J. M.; Occhi, M.; McDowell, W. H.

2012-12-01

Atmospheric mercury (Hg) in wet deposition at the Luquillo Experimental Forest in northeastern Puerto Rico, averages 28 μg m-2 yr-1, higher than any site in the USA Mercury Deposition Network. Despite the high deposition, Hg content of soils, vegetation, and biota are below global averages. The low Hg content of watershed surfaces, coupled with exceptionally high stream total Hg flux, suggest that most of the Hg passes through the watershed with minimal retention. We assessed Hg dynamics in two adjacent watersheds, Rio Icacos underlain by quartz diorite, and Rio Mameyes underlain by volcaniclastic rocks. At both sites, high-flow Hg concentrations approached 100 ng L-1, dominated by particulate Hg. In order to assess the apparent pass-through nature of Hg in this tropical forest, we measured 7Be and 10Be isotopes from natural, cosmogenic fallout adsorbed on stream suspended particles to constrain the Hg age /residence time and source (atmospheric vs. geogenic or legacy Hg from 19th century gold mining). Ubiquitous 7Be (half-life 53 days) and relatively high 7Be/10Be ratios on suspended particles suggest that stream Hg was dominated by erosion from exposed surfaces, supporting a short residence time. The low watershed retention of the high Hg throughput limits adverse biological effects in this tropical ecosystem.

Characterization of laser deposited Ti6Al4V/TiC composite powders on a Ti6Al4V substrate

CSIR Research Space (South Africa)

Mahamood, RM

2014-01-01

Full Text Available This paper reports the material characterization of Ti6Al4V/TiC composite produced by laser metal deposition. The Ti6Al4V/TiC composites were deposited with a composition ratio of 50 wt.% Ti64l4V and 50 wt.% TiC. The depositions were achieved...

Stratigraphic reconstruction of two debris avalanche deposits at Colima Volcano (Mexico): Insights into pre-failure conditions and climate influence

Science.gov (United States)

Roverato, M.; Capra, L.; Sulpizio, R.; Norini, G.

2011-10-01

Throughout its history, Colima Volcano has experienced numerous partial edifice collapses with associated emplacement of debris avalanche deposits of contrasting volume, morphology and texture. A detailed stratigraphic study in the south-eastern sector of the volcano allowed the recognition of two debris avalanche deposits, named San Marcos (> 28,000 cal yr BP, V = ~ 1.3 km 3) and Tonila (15,000-16,000 cal yr BP, V = ~ 1 km 3 ). This work sheds light on the pre-failure conditions of the volcano based primarily on a detailed textural study of debris avalanche deposits and their associated pyroclastic and volcaniclastic successions. Furthermore, we show how the climate at the time of the Tonila collapse influenced the failure mechanisms. The > 28,000 cal yr BP San Marcos collapse was promoted by edifice steep flanks and ongoing tectonic and volcanotectonic deformation, and was followed by a magmatic eruption that emplaced pyroclastic flow deposits. In contrast, the Tonila failure occurred just after the Last Glacial Maximum (22,000-18,000 cal BP) and, in addition to the typical debris avalanche textural characteristics (angular to sub-angular clasts, coarse matrix, jigsaw fit) it shows a hybrid facies characterized by debris avalanche blocks embedded in a finer, homogenous and partially cemented matrix, a texture more characteristic of debris flow deposits. The Tonila debris avalanche is directly overlain by a 7-m thick hydromagmatic pyroclastic succession. Massive debris flow deposits, often more than 10 m thick and containing large amounts of tree trunk logs, represent the top unit in the succession. Fluvial deposits also occur throughout all successions; these represent periods of highly localized stream reworking. All these lines of evidence point to the presence of water in the edifice prior to the Tonila failure, suggesting it may have been a weakening factor. The Tonila failure appears to represent an anomalous event related to the particular climatic

Geology and regional setting of the Al Masane ancient mine area, southeastern Arabian Shield, Kingdom of Saudi Arabia

Science.gov (United States)

Conway, Clay M.

1985-01-01

Stratiform zinc-copper massive-sulfide deposits at Al Masane occur in thin dolomitic interbeds within Proterozoic felsic crystal tuff and mafic flows and volcaniclastics. These strata dip steeply westward and are underlain by shale and shaly graywacke to the east and overlain by lapilli crystal tuff to the west. This section is part of the Habawnah fold or mineral belt that extends from the Wadi Wassat area southward into Yemen. Western parts of the Habawnah fold belt, including the Al Masane area, are characterized by a bimodal assemblage of of phenocryst-poor basalts and sodic rhyolite crystal tuff, and by zinc-copper mineral deposits. Strata in the eastern part of the belt, mostly east of the Ashara fault zone, contain abundant phenocryst-rich mafic volcanic rocks, little felsic crystal tuff, and barren or locally nickeliferous massive pyrite deposits.

Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

Energy Technology Data Exchange (ETDEWEB)

Palla-Papavlu, A., E-mail: apalla@nipne.ro [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Rusen, L.; Dinca, V.; Filipescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Lippert, T. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen PSI (Switzerland); Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania)

2014-05-01

In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm{sup 2} the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

Science.gov (United States)

Palla-Papavlu, A.; Rusen, L.; Dinca, V.; Filipescu, M.; Lippert, T.; Dinescu, M.

2014-05-01

In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm2 the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

Chemical vapour deposition growth and Raman characterization of graphene layers and carbon nanotubes

Science.gov (United States)

Lai, Y.-C.; Rafailov, P. M.; Vlaikova, E.; Marinova, V.; Lin, S. H.; Yu, P.; Yu, S.-C.; Chi, G. C.; Dimitrov, D.; Sveshtarov, P.; Mehandjiev, V.; Gospodinov, M. M.

2016-02-01

Single-layer graphene films were grown by chemical vapour deposition (CVD) on Cu foil. The CVD process was complemented by plasma enhancement to grow also vertically aligned multiwalled carbon nanotubes using Ni nanoparticles as catalyst. The obtained samples were characterized by Raman spectroscopy analysis. Nature of defects in the samples and optimal growth conditions leading to achieve high quality of graphene and carbon nanotubes are discussed.

Plasma Deposition and Characterization of Copper-doped Cobalt Oxide Nanocatalysts

Directory of Open Access Journals (Sweden)

Jacek TYCZKOWSKI

2013-09-01

Full Text Available A series of pure and copper-doped cobalt oxide films was prepared by plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD. The effect of Cu-doping on the chemical structure and morphology of the deposited films was investigated. Raman and FTIR spectroscopies were used to characterize the chemical structure and morphology of the produced films. The bulk composition and homogeneity of the samples were investigated by energy dispersive X-ray microanalysis (EDX, and X-ray photoelectron spectroscopy (XPS was employed to assess the surface chemical composition of pure and doped materials. The obtained results permit to affirm that the PEMOCVD technique is a simple, versatile and efficient method for providing homogeneous layers of cobalt oxides with a different content of copper. It has been found that pure cobalt oxide films mainly contain Co3O4 in the form of nanoclusters whereas the films doped with Cu are much more complex, and CoOx (also Co3O4, mixed Co-Cu oxides and CuOx nanoclusters are detected in them. Preliminary catalytical tests show that Cu-doped cobalt oxide films allow to initiate catalytic combustion of n-hexane at a lower temperature compared to the pure cobalt oxide (Co3O4 films. From what has been stated above, the plasma-deposited thin films of Cu-doped cobalt oxides pave the way towards a new class of nanomaterials with interesting catalytic properties. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.2320

Reactive physical vapor deposition of TixAlyN: Integrated plasma-surface modeling characterization

International Nuclear Information System (INIS)

Zhang Da; Schaeffer, J.K.

2004-01-01

Reactive physical vapor deposition (RPVD) has been widely applied in the microelectronic industry for producing thin films. Fundamental understanding of RPVD mechanisms is needed for successful process development due to the high sensitivity of film properties on process conditions. An integrated plasma equipment-target nitridation modeling infrastructure for RPVD has therefore been developed to provide mechanistic insights and assist optimal process design. The target nitridation model computes target nitride coverage based on self-consistently derived plasma characteristics from the plasma equipment model; target sputter yields needed in the plasma equipment model are also self-consistently derived taking into account the yield-suppressing effect from nitridation. The integrated modeling infrastructure has been applied to investigating RPVD processing with a Ti 0.8 Al 0.2 compound target and an Ar/N 2 gas supply. It has been found that the process produces athermal metal neutrals as the primary deposition precursor. The metal stoichiometry in the deposited film is close to the target composition due to the predominance of athermal species in the flux that reaches the substrate. Correlations between process parameters (N 2 flow, target power), plasma characteristics, surface conditions, and deposition kinetics have been studied with the model. The deposition process is characterized by two regimes when the N 2 flow rate is varied. When N 2 is dilute relative to argon, target nitride coverage increases rapidly with increasing N 2 flow. The sputter yield and deposition rate consequently decrease. For less dilute N 2 mixtures, the sputter yield and deposition rate are stable due to the saturation of target nitridation. With increasing target power, the electron density increases nearly linearly while the variation of N generation is much smaller. Target nitridation and its suppression of the sputter yield saturate at high N 2 flow rendering these parameters

Atmospheric particle characterization, distribution, and deposition in Xi'an, Shaanxi Province, Central China

Energy Technology Data Exchange (ETDEWEB)

Cao Zongze; Yang Yuhua [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China); Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada); Lu, Julia, E-mail: julialu@ryerson.c [Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada); Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China); Zhang Chengxiao, E-mail: cxzhang@snnu.edu.c [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China)

2011-02-15

Physical characterization and chemical analysis of settled dusts collected in Xi'an from November 2007 to December 2008 show that (1) dust deposition rates ranged from 14.6 to 350.4 g m{sup -2} yr{sup -1}. The average deposition rate (76.7 g m{sup -2} yr{sup -1}) ranks the 11th out of 56 dust deposition rates observed throughout the world. The coal-burning power was the major particle source; (2) on average (except site 4), {approx}10% of the settled dusts having size <2.6, {approx}30% having size <10.5, and >70% having size <30 {mu}m; (3) the concentrations for 20 out of 27 elements analyzed were upto 18 times higher than their soil background values in China. With such high deposition rates of dusts that contain elevated levels of toxic elements, actions should be taken to reduce emission and studies are needed to assess the potential impacts of settled particles on surface ecosystem, water resource, and human health in the area. - Research highlights: High atmospheric dust deposition rate in Xi'an, Shaanxi, China. Coal-burning power plan being a major source of particulate matter in Xi'an area. High levels of toxic elements in the settled dusts. Enrichment of heavy metals (e.g., Pb, Ni, Cu) in fine particles. - Atmospheric dust deposition rate is high and the levels of toxic elements associated with the settled dusts are elevated in Xi'an, Shaanxi, China.

Sedimentation in a Submarine Seamount Apron at Site U1431, International Ocean Discovery Program Expedition 349, South China Sea

Science.gov (United States)

Dadd, K. A.; Clift, P. D.; Hyun, S.; Jiang, T.; Liu, Z.

2014-12-01

International Ocean Discovery Program (IODP) Expedition 349 Site U1431 is located near the relict spreading ridge in the East Subbasin of the South China Sea. Holes at this site were drilled close to seamounts and intersected the volcaniclastic apron. Volcaniclastic breccia and sandstone at Site U1431 are dated as late middle Miocene to early late Miocene (~8-13 Ma), suggesting a 5 m.y. duration of seamount volcanism. The apron is approximately 200 m thick and is sandwiched between non-volcaniclastic units that represent the background sedimentation. These comprise dark greenish gray clay, silt, and nannofossil ooze interpreted as turbidite and hemipelagic deposits that accumulated at abyssal water depths. At its base, the seamount sequence begins with dark greenish gray sandstone, siltstone, and claystone in upward fining sequences interpreted as turbidites intercalated with minor intervals of volcaniclastic breccia. Upsection the number and thickness of breccia layers increases with some beds up to 4.8 m and possibly 14.5 m thick. The breccia is typically massive, ungraded, and poorly sorted with angular to subangular basaltic clasts, as well as minor reworked subrounded calcareous mudstone, mudstone, and sandstone clasts. Basaltic clasts include nonvesicular aphyric basalt, sparsely vesicular aphyric basalt, highly vesicular aphyric basalt, and nonvesicular glassy basalt. Mudstone clasts are clay rich and contain foraminifer fossils. The matrix comprises up to 40% of the breccia beds and is a mix of clay, finer grained altered basalt clasts, and mafic vitroclasts with rare foraminifer fossils. Some layers have calcite cement between clasts. Volcaniclastic sandstone and claystone cycles interbedded with the breccia layers have current ripples and parallel laminations indicative of high-energy flow conditions during sedimentation. The breccia beds were most likely deposited as a series of debris flows or grain flows. This interpretation is supported by their

Origin and depositional environment of clastic deposits in the Hilo drill hole, Hawaii

Science.gov (United States)

Beeson, M.H.; Clague, D.A.; Lockwood, J.P.

1996-01-01

Volcaniclastic units cored at depths of about 87, 164, 178, 226, and 246 m below sea level and carbonate units located between depths of 27 and 53 m below sea level in the Hilo drill core were found to be deposited at or near sea level. Four of these units are hydroclastic deposits, formed when subaerially erupted Mauna Loa lava flows entered the ocean and fragmented to produce quenched, glassy fragments during hydrovolcanic explosions. Ash units 24 and 26, at 178 m depth, accumulated at sea level in a freshwater bog. They contain pyroxenes crystallized from tholeiitic magma that we infer erupted explosively at the summit of Kilauea volcano. Two carbon-rich layers from these ashes have a weighted average radiocarbon age of 38.6 ?? 0.9 ka; the ashes probably correlate with the oldest and thickest part of the Pahala ash. Ash unit 44, at the transition from Mauna Kea to Mauna Loa lava flows, was probably nearly 3.2 m thick and is inferred to be equivalent to the lower thick part of the composite Homelani ash mapped in Hilo and on the flanks of Mauna Kea. The age of this part of Homelani ash is between 128 ?? 33 and 200 ?? 10 ka; it may have erupted subglacially during the Pohakuloa glacial maxima on Mauna Kea. Beach sand units 12 and 22 were derived from nearby Mauna Loa and Mauna Kea lava flows. The middle of beach sand unit 38 was derived mainly from lava erupted near the distal end of the subaerial east rift zone of Kilauea volcano; these sands were transported about 33 km northwest to Hilo Bay by prevailing longshore currents. Combined age, depth, and sea level markers in the core allow us to determine that lava flow recurrence intervals averaged one flow every 4 kyr during the past 86 kyr and one flow every 16 kyr between 86 and 200 ka at the drill site and that major explosive eruptions that deposit thick ash in Hilo have occurred only twice in the last 400 kyr. These recurrence intervals support the moderate lava flow hazard zonation (zone 3) for coastal Hilo

Characterization of Deposited Platinum Contacts onto Discrete Graphene Flakes for Electrical Devices

KAUST Repository

Holguin Lerma, Jorge Alberto

2016-01-01

The electrical measurements confirm a 99.5% reduction in contact resistance after vacuum thermal annealing at 300 °C. Parallel to this, Raman characterization confirms the formation of a nanocrystalline carbon structure over the electrode. While this could suggest an enhancement of the electrical transport in the device, an additional thermal annealing step in air at 300 °C, promoted the oxidation and removal of the carbon shell and confirmed that the contact resistance remained the same. Overall this shows that the carbon shell along the electrode has no significant role in the contact resistance. Finally, the challenges based on topographical analysis of the deposited electrodes are discussed. Reduction of the electrode’s height down to one-third of the initial value, increased surface roughness, formation of voids along the electrodes and the onset of platinum nanoparticles near the area of deposition, represent a challenge for future work.

A quantitative x-ray diffraction inventory of volcaniclastic inputs into the marine sediment archives off Iceland: a contribution to the Volcanoes in the Arctic System programme

Directory of Open Access Journals (Sweden)

Dennis D. Eberl

2013-02-01

Full Text Available This paper re-evaluates how well quantitative x-ray diffraction (qXRD can be used as an exploratory method of the weight percentage (wt% of volcaniclastic sediment, and to identify tephra events in marine cores. In the widely used RockJock v6 software programme, qXRD tephra and glass standards include the rhyodacite White River tephra (Alaska, a rhyolitic tephra (Hekla-4 and the basaltic Saksunarvatn tephra. Experiments of adding known wt% of tephra to felsic bedrock samples indicated that additions ≥10 wt% are accurately detected, but reliable estimates of lesser amounts are masked by amorphous material produced by milling. Volcaniclastic inputs range between 20 and 50 wt%. Primary tephra events are identified as peaks in residual qXRD glass wt% from fourth-order polynomial fits. In cores where tephras have been identified by shard counts in the >150 µm fraction, there is a positive correlation (validation with peaks in the wt% glass estimated by qXRD. Geochemistry of tephra shards confirms the presence of several Hekla-sourced tephras in cores B997-317PC1 and -319PC2 on the northern Iceland shelf. In core B997-338 (north-west Iceland, there are two rhyolitic tephras separated by ca. 100 cm with uncorrected radiocarbon dates on articulated shells of around 13 000 yr B.P. These tephras may be correlatives of the Borrobol and Penifiler tephras found in Scotland. The number of Holocene tephra events per 1000 yr was estimated from qXRD on 16 cores and showed a bimodal distribution with an increased number of events in both the late and early Holocene.

Deposition and Characterization of Hermetic, Biocompatible Thin Film Coatings for Implantable, Electrically Active Devices

Science.gov (United States)

Sweitzer, Robyn K.

Retinal prostheses may be used to support patients suffering from Age-related macular degeneration or retinitis pigmentosa. A hermetic encapsulation of the poly(imide )-based prosthesis is important in order to prevent the leakage of water and ions into the electric circuitry embedded in the poly(imide) matrix. The deposition of amorphous aluminum oxide (by sputtering) and diamond like carbon (by pulsed laser ablation and vacuum arc vapor deposition) were studied for the application in retinal prostheses. The resulting thin films were characterized for composition, thickness, adhesion and smoothness by scanning electron microscopy-energy dispersive spectroscopy, atomic force microscopy, profilometry and light microscopy. Electrical stability was evaluated and found to be good. The as-deposited films prevented incursion of salinated fluids into the implant over two (2) three month trials soaking in normal saline at body temperature, Biocompatibility was tested in vivo by implanting coated specimen subretinally in the eye of Yucatan pigs. While amorphous aluminum oxide is more readily deposited with sufficient adhesion quality, biocompatibility studies showed a superior behavior of diamond-like carbon. Amorphous aluminum oxide had more adverse effects and caused more severe damage to the retinal tissue.

Preparation and characterization of SnO2 thin film by chemical bath deposition method for solar cell application

International Nuclear Information System (INIS)

Wan Mohd Zin Wan Yunus; Saeideh Ebrahimiasl; Anuar Kassim

2009-01-01

Full text: Tin oxide thin films were synthesized by chemical bath deposition method on glass substrate .The as-deposited thin films were characterized for compositional, structural, surface morphological, optical and electrical properties. The X-ray diffraction patterns of the sample indicate that all samples are polycrystalline structure. AFM images show that the films consist of small uniform grains and are free of pinholes. (author)

Ultrashort Pulsed Laser Ablation of Magnesium Diboride: Plasma Characterization and Thin Films Deposition

Directory of Open Access Journals (Sweden)

Angela De Bonis

2015-01-01

Full Text Available A MgB2 target has been ablated by Nd:glass laser with a pulse duration of 250 fs. The plasma produced by the laser-target interaction, showing two temporal separated emissions, has been characterized by time and space resolved optical emission spectroscopy and ICCD fast imaging. The films, deposited on silicon substrates and formed by the coalescence of particles with nanometric size, have been analyzed by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. The first steps of the films growth have been studied by Transmission Electron Microscopy. The films deposition has been studied by varying the substrate temperature from 25 to 500°C and the best results have been obtained at room temperature.

Effect of oxygen partial pressure on the microstructural, optical and gas sensing characterization of nanostructured Gd doped ceria thin films deposited by pulsed laser deposition

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Nagaraju P.

2017-12-01

Full Text Available Microstructural properties of 10 mol% gadolinium doped ceria (CeO2 thin films that were deposited on quartz substrate at substrate temperature of 1023 K by using pulsed laser deposition with different oxygen partial pressures in the range of 50–200 mTorr. The influence of oxygen partial pressure on microstructural, morphological, optical and gas sensing characterization of the thin films was systematically studied. The microstructure of the thin films was investigated using X-ray diffraction, atomic force microscopy and Raman spectroscopy. Morphological studies have been carried out using scanning electron microscope. The experimental results confirmed that the films were polycrystalline in nature with cubic fluorite structure. Optical properties of the thin films were examined using UV–vis spectrophotometer. The optical band gap calculated from Tauc’s relation. Gas sensing characterization has been carried at different operating temperatures (room temperature to 523 K for acetone gas. Response and recovery times of the sensor were calculated using transient response plot.

Economical Atomic Layer Deposition

Science.gov (United States)

Wyman, Richard; Davis, Robert; Linford, Matthew

2010-10-01

Atomic Layer Deposition is a self limiting deposition process that can produce films at a user specified height. At BYU we have designed a low cost and automated atomic layer deposition system. We have used the system to deposit silicon dioxide at room temperature using silicon tetrachloride and tetramethyl orthosilicate. Basics of atomic layer deposition, the system set up, automation techniques and our system's characterization are discussed.

Deposition and characterization of multilayers on thin foil x-ray mirrors for high-throughput x-ray telescopes

DEFF Research Database (Denmark)

Hussain, Ahsen M.; Joensen, Karsten D.; Hoeghoej, P.

1996-01-01

W/Si and Co/C multilayers have been deposited on epoxy- replicated Au mirrors from the ASTRO-E telescope project, SPectrum Roentgen Gamma (SRG) flight mirrors, DURAN glass substrates and Si witness wafers. A characterization of the multilayers with both hard x-rays and soft x-rays is presented....... This clearly indicates the effectiveness of the epoxy-replication process for the production of smooth substrates for multilayer deposition to be used in future x-ray telescopes....

Mechanical Characterization of Polydopamine-Assisted Silver Deposition on Polymer Substrates

Science.gov (United States)

Cordes, Amanda Laurence

Inspired by the adhesive proteins in marine mussels, polydopamine has become a popular adhesive ad-layer for surface functionalization of a variety of substrates. Based on the chemistry of the dopamine monomer, amine and thiol functional groups are hypothesized to increase adhesion between polymer substrates and polydopamine thin films. This hypothesis was the central motivation for development of a tailorable thiol-ene system in order to study the effects of substrate chemistry on polydopamine adhesion. While polydopamine-adhered silver has been studied on a variety of substrates, no in depth mechanical characterization has been performed and to date, no research has been published on thiol-enes coated in polydopamine-adhered silver. The purpose of this study was to characterize the mechanical durability and adhesion properties of a polydopamine-adhered silver film on commercial substrates and a tailorable thiol-ene system. Polydopamine and silver coatings were deposited on a variety of polymer substrates through a simple dip-coat process. The polydopamine forms a thin uniform adhesive layer and the silver deposits in a discontinuous manner with a nanoparticle sized base layer covering the full surface and micron-sized clusters adhered sporadically on top. Mechanical tensile testing was performed to characterize the durability of the silver coating on commercial polymers. Coated nylon and HDPE showed no signs of degradation or delamination of the polydopamine-adhered silver coating up to 30% strain although both substrates showed large plastic deformation. Peel tests were performed on both commercial polymers as well as a tailorable thiol-ene system. Results support the hypothesis that polydopamine adhesion is increased with the presence of functional groups. Parts of the HDPE sample were cleanly peeled, but silver patches were left sporadically across the surface pointing to weaker adhesion between polyethylene and polydopamine. A high adhesive strength tape was

Characterization of Chemical Vapor Deposited Tetraethyl Orthosilicate based SiO2 Films for Photonic Devices

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Jhansirani KOTCHARLAKOTA

2016-05-01

Full Text Available Silicon has been the choice for photonics technology because of its cost, compatibility with mass production and availability. Silicon based photonic devices are very significant from commercial point of view and are much compatible with established technology. This paper deals with deposition and characterization of SiO2 films prepared by indigenously developed chemical vapor deposition system. Ellipsometry study of prepared films showed an increase in refractive index and film thickness with the increment in deposition temperature. The deposition temperature has a significant role for stoichiometric SiO2 films, FTIR measurement has shown the three characteristics peaks of Si-O-Si through three samples prepared at temperatures 700, 750 and 800 °C while Si-O-Si stretching peak positions were observed to be shifted to lower wavenumber in accordance to the temperature. FESEM analysis has confirmed the smooth surface without any crack or disorder while EDX analysis showed the corresponding peaks of compositional SiO2 films.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.7245

Development of Deposition and Characterization Systems for Thin Film Solar Cells

Science.gov (United States)

Cimaroli, Alexander J.

Photovoltaic (PV) devices are becoming more important due to a number of economic and environmental factors. PV research relies on the ability to quickly fabricate and characterize these devices. While there are a number of deposition methods that are available in a laboratory setting, they are not necessarily able to be scaled to provide high throughput in a commercial setting. A close-space sublimation (CSS) system was developed to provide a means of depositing thin films in a very controlled and scalable manner. Its viability was explored by using it to deposit the absorber layer in Zn3P2 and CdTe solar cell devices. Excellent control over morphology and growth conditions and a high level of repeatability was demonstrated in the study of textured Zn3P2 thin films. However, some limitations imposed by the structure of Zn3P 2-based PV devices showed that CSS may not be the best approach for depositing Zn3P2 thin films. Despite the inability to make Zn3P2 solar cell devices, high efficiency CdTe solar cells were fabricated using CSS. With the introduction of Perovskite-based solar cell devices, the viability of data collected from conventional J-V measurements was questioned due to the J-V hysteresis that Perovskite devices exhibited. New methods of solar cell characterization were developed in order to accurately and quickly assess the performance of hysteretic PV devices. Both J-V measurements and steady-state efficiency measurements are prone to errors due to hysteresis and maximum power point drift. To resolve both of these issues, a maximum power point tracking (MPPT) system was developed with two algorithms: a simple algorithm and a predictive algorithm. The predictive algorithm showed increased resistance to the effects of hysteresis because of its ability to predict the steady-state current after a bias step with a double exponential decay model fit. Some publications have attempted to quantify the degree of J-V hysteresis present in fabricated Perovskite

Corrosion resistance and characterization of metallic coatings deposited by thermal spray on carbon steel

International Nuclear Information System (INIS)

Sá Brito, V.R.S.; Bastos, I.N.; Costa, H.R.M.

2012-01-01

Highlights: ► Five combinations of metallic coatings and intermediate bonds were deposited on carbon steels. ► High strength was reached in adhesion tests. ► Epoxy sealing of coatings improves corrosion resistance. -- Abstract: Carbon steels are not resistant to corrosion and several methods are used in surface engineering to protect them from aggressive environments such as marine. The main objective of this work is the evaluation of mechanical and metallurgical properties of five metallic coatings produced by thermal spray on carbon steel. Five chemical compositions were tested in order to give a large panel of possibility. Coatings were characterized by several methods to result in a screening of their performance. At first, the assessment of microstructural morphology by optical microscopy (OM) and by scanning electron microscopy (SEM) was made. OM and SEM results showed uniformity of deposited layer, low amount of oxides and porosity. The physical properties of coatings were also evaluated by microhardness measurement, adhesion and porosity quantification. The corrosion resistance was analyzed in salt spray and electrochemical polarization tests. In the polarization test, as well as in the salt spray, all sealed conditions presented low corrosion. A new intermediate 78.3Ni20Cr1.4Si0.3Fe alloy was studied in order to reduce pores and microcracks that are frequently found in ordinary 95Ni5Al alloy. Based on the performed characterizations, the findings suggested that the FeCrCo deposition, with an epoxy sealing, is suitable to be used as an efficient coating of carbon steel in aggressive marine environments.

Hydrogeologic characterization of the Cachoeira Deposit Massif, Caetite, state of Bahia, Brazil

International Nuclear Information System (INIS)

Bottura, J.A.; Albuquerque Filho, J.L.; Ojima, L.M.

1984-01-01

The hydrogeologic applications for the characterization of rock massifs in future mining activity areas are presented. The study was performed in the Cachoeira uranium deposit (Anomaly no.13 - Lagoa Real Project) located in the south-central portion of the state of Bahia, Caetite municipality, belonging to the Brazilian Nuclear Enterprise - NUCLEBRAS. The massif occuring in the area is composed of a group or series of rocks classified generically as gneisses, displaying different geotechnical classes. In order to consubstantiate the hydrogeologic/ hydrogeotechnical characterization, pumping and infiltration tests were performed, as well as periodic water level measurements in piezometers and drill-holes. In this manner, a hydrogeotechnical classification was made possible and a quantitative evaluation of the volume of water that will be drained was elaborated, orviding necessary contributions for research diggings and exploration. (D.J.M.) [pt

Application of X-ray micro-CT for micro-structural characterization of APCVD deposited SiC coatings on graphite conduit.

Science.gov (United States)

Agrawal, A K; Sarkar, P S; Singh, B; Kashyap, Y S; Rao, P T; Sinha, A

2016-02-01

SiC coatings are commonly used as oxidation protective materials in high-temperature applications. The operational performance of the coating depends on its microstructure and uniformity. This study explores the feasibility of applying tabletop X-ray micro-CT for the micro-structural characterization of SiC coating. The coating is deposited over the internal surface of pipe structured graphite fuel tube, which is a prototype of potential components of compact high-temperature reactor (CHTR). The coating is deposited using atmospheric pressure chemical vapor deposition (APCVD) and properties such as morphology, porosity, thickness variation are evaluated. Micro-structural differences in the coating caused by substrate distance from precursor inlet in a CVD reactor are also studied. The study finds micro-CT a potential tool for characterization of SiC coating during its future course of engineering. We show that depletion of reactants at larger distances causes development of larger pores in the coating, which affects its morphology, density and thickness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

Energy Technology Data Exchange (ETDEWEB)

Sagdeo, P R; Shinde, D D; Misal, J S [Optics and Thin Film Laboratory, Autonagar, BARC-Vizag, Visakhapatnam -530012 (India); Kamble, N M; Tokas, R B; Biswas, A; Poswal, A K; Thakur, S; Bhattacharyya, D; Sahoo, N K; Sabharwal, S C, E-mail: nksahoo@barc.gov.i, E-mail: sahoonk@gmail.co [Spectroscopy Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2010-02-03

Titania-silica (TiO{sub 2}/SiO{sub 2}) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser ({lambda} = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

International Nuclear Information System (INIS)

Sagdeo, P R; Shinde, D D; Misal, J S; Kamble, N M; Tokas, R B; Biswas, A; Poswal, A K; Thakur, S; Bhattacharyya, D; Sahoo, N K; Sabharwal, S C

2010-01-01

Titania-silica (TiO 2 /SiO 2 ) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser (λ = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

Changing fluvial styles in volcaniclastic successions: A cretaceous example from the Cerro Barcino Formation, Patagonia

Science.gov (United States)

Umazano, A. Martín; Krause, J. Marcelo; Bellosi, Eduardo S.; Perez, Mariano; Visconti, Graciela; Melchor, Ricardo N.

2017-08-01

-sinuosity, fluvial system, and displays both an increase of lacustrine facies and a decrease of ash-fall deposits. The interval 3 (7.5-27 m thick) corresponds to the middle part of the CCM, and lacks channel-belt bodies. It has the highest participation of sheet-flood and ash-fall deposits. This interval entirely records a pedogenized floodplain setting. In relation to the interval 2, participation of debris-flow deposits remains constant and lacustrine facies subtly increases. The interval 4 (18-148 m thick) represents the upper part of the CCM. It comprises an alternation of channel-belt bodies and pedogenized floodplain facies, the last characterized by sheet-flood, lake, debris-flow, and volcanic ash rain deposits. The mean palaeoflow was toward E-SE, except in the two localities positioned further north where the drainage was towards NE and SSE. Proportion of channel-belt deposits ranges from 6 to 32%. It represents channelized and perennial fluvial systems with meandering and locally low-sinuosity styles. Increase in channel proportion and thicker channel bodies are in the northern part of the study area. Particularly, in Puesto Mesa-Cerro León locality this interval is the thickest and has the highest proportion of thicker channel-belt bodies. We interpret these changes in facies architecture as the response to alternated periods of high (intervals 1 and 3) and low (intervals 2 and 4) primary pyroclastic sediment supply. Moreover, there was a climatic change to wetter conditions (intervals 1 to 2-4); as well as intrabasinal tectonic activity in northern area for intervals 2 and 4 inferred from palaeocurrent data.

Electrochemical characterization of the underpotential deposition of tellurium on Au electrode

International Nuclear Information System (INIS)

Zhu, W.; Yang, J.Y.; Zhou, D.X.; Bao, S.Q.; Fan, X.A.; Duan, X.K.

2007-01-01

Electrochemical characterization of the underpotential deposition (UPD) of tellurium on Au substrate has been performed in this paper. The mechanism of Te deposition and its voltammetry dependence on the Te ion concentration were studied, and it suggests that variations in the metal ion concentration may affect the UPD process kinetics. The effect of tellurium adsorbates on UPD behavior of Te has also been investigated. The results show that the tellurium adsorbates could be irreversibly adsorbed upon the Au substrate surface under the open-circuit conditions. Subsequent removal of the Te adsorbates was also proved to be very difficult within the Au double-layer region, and a standard electrochemical cleaning procedure is necessary to remove the Te adsorbates completely. When the potential was cycled into the Au oxidation region, a substantial loss of Te adsobates was observed, which occurs simultaneously with the Au oxidation features. Scan rate dependent cyclic voltammetry experiments reveal that the peak current in the Te UPD peak is not a linear function of the scan rate, ν, but of a 2/3 power of the scan rate, ν 2/3 . It is in good consistent with a two-dimension nucleation and growth mechanism

Electrochemical characterization of silver nanorod electrodes prepared by oblique angle deposition

Energy Technology Data Exchange (ETDEWEB)

Tang, X-J [Department of Physics and Astronomy, Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 (United States); Zhang, G [Department of Biological and Agriculture Engineering, Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 (United States); Zhao, Y-P [Department of Physics and Astronomy, Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 (United States)

2006-09-14

Ag nanorod electrodes with different nanorod lengths are fabricated by a simple vacuum deposition technique, oblique angle deposition (OAD). The as-grown Ag nanorods are aligned on the substrate and have a diameter of {approx}60-70 nm, a density of {approx}200-300 x 10{sup 7} cm{sup -2}, and a tilting angle of {approx}70 deg. -80 deg. with respect to the surface normal. The electrochemical behaviours of the Ag nanorod electrode are characterized by cyclic voltammetry at various scan rates with comparison to an Ag thin-film electrode. The capacitive current is found to be proportional to the actual surface area, and the faradic redox current also increases monotonically with the surface area of the nanorod electrodes, but the increase is not as significant as that of the capacitive current due to the diffusion layer overlapping for the highly compacted nanorods. This indicates that the Ag nanorod electrode could improve the electrolytic sensor for amperometric response measurements, especially for the bimolecular measurements due to the biocompatibility of Ag. The high capacitance also suggests a promising usage of the developed nanostructures for battery and energy storage applications.

Electrochemical deposition and characterization of zinc–nickel alloys deposited by direct and reverse current

Directory of Open Access Journals (Sweden)

JELENA B. BAJAT

2005-12-01

Full Text Available Zn–Ni alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of Zn–Ni alloys during exposure to a corrosive agent (3 % NaCl solution. It was shown that the Zn–Ni alloy electrodeposited by reverse current with a full period T = 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.

Deposition and characterization of IrOx nanofoils on carbon nanotube templates by reactive magnetron sputtering

International Nuclear Information System (INIS)

Chen, Yi-Min; Cai, Jhen-Hong; Huang, Ying-Sheng; Lee, Kuei-Yi; Tsai, Dah-Shyang; Tiong, Kwong-Kau

2012-01-01

Large surface area IrO x nanofoils (IrO x NF) were deposited on multi-wall carbon nanotube (MWCNT) templates, forming IrO x /MWCNT nanocomposites, by reactive radio frequency magnetron sputtering using Ir metal target. The structural and spectroscopic properties of IrO x NF were characterized. The micrographs of field emission scanning electron microscopy showed the formation of foil-like structure for the as-deposited samples. Transmission electron microscopy analysis revealed the contiguous presence of glassy iridium oxide, iridium metal, and iridium dioxide nanocrystals in the foil. X-ray photoelectron spectroscopy analysis provided the information of the oxidation states and the stoichiometry of IrO x NF. Raman spectra revealed the amorphous-like phase of the as-deposited IrO x NF. The nanofoil structure provided ultra-high surface area for electrical charge storage which made the IrO x /MWCNT nanocomposites as an attractive candidate for the supercapacitor applications.

Characterization of Si:O:C:H films fabricated using electron emission enhanced chemical vapour deposition

Energy Technology Data Exchange (ETDEWEB)

Durrant, Steven F. [Laboratorio de Plasmas Tecnologicos, Campus Experimental de Sorocaba, Universidade Estadual Paulista-UNESP, Avenida Tres de Marco, 511, Alto da Boa Vista, 18087-180, Soracaba, SP (Brazil)], E-mail: steve@sorocaba.unesp.br; Rouxinol, Francisco P.M.; Gelamo, Rogerio V. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, 13083-970, Campinas, SP (Brazil); Trasferetti, B. Claudio [Present address: Superintendencia Regional da Policia Federal em Sao Paulo, Setor Tecnico-Cientifico, Rua Hugo d' Antola 95/10o Andar, Lapa de Baixo, 05038-090 Sao Paulo, SP (Brazil); Davanzo, C.U. [Instituto de Quimica, Universidade Estadual de Campinas, 13083-970, Campinas, SP (Brazil); Bica de Moraes, Mario A. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, 13083-970, Campinas, SP (Brazil)

2008-01-15

Silicon-based polymers and oxides may be formed when vapours of oxygen-containing organosilicone compounds are exposed to energetic electrons drawn from a hot filament by a bias potential applied to a second electrode in a controlled atmosphere in a vacuum chamber. As little deposition occurs in the absence of the bias potential, electron impact fragmentation is the key mechanism in film fabrication using electron-emission enhanced chemical vapour deposition (EEECVD). The feasibility of depositing amorphous hydrogenated carbon films also containing silicon from plasmas of tetramethylsilane or hexamethyldisiloxane has already been shown. In this work, we report the deposition of diverse films from plasmas of tetraethoxysilane (TEOS)-argon mixtures and the characterization of the materials obtained. The effects of changes in the substrate holder bias (V{sub S}) and of the proportion of TEOS in the mixture (X{sub T}) on the chemical structure of the films are examined by infrared-reflection absorption spectroscopy (IRRAS) at near-normal and oblique incidence using unpolarised and p-polarised, light, respectively. The latter is particularly useful in detecting vibrational modes not observed when using conventional near-normal incidence. Elemental analyses of the film were carried out by X-ray photoelectron spectroscopy (XPS), which was also useful in complementary structural investigations. In addition, the dependencies of the deposition rate on V{sub S} and X{sub T} are presented.

Characterization of Si:O:C:H films fabricated using electron emission enhanced chemical vapour deposition

International Nuclear Information System (INIS)

Durrant, Steven F.; Rouxinol, Francisco P.M.; Gelamo, Rogerio V.; Trasferetti, B. Claudio; Davanzo, C.U.; Bica de Moraes, Mario A.

2008-01-01

Silicon-based polymers and oxides may be formed when vapours of oxygen-containing organosilicone compounds are exposed to energetic electrons drawn from a hot filament by a bias potential applied to a second electrode in a controlled atmosphere in a vacuum chamber. As little deposition occurs in the absence of the bias potential, electron impact fragmentation is the key mechanism in film fabrication using electron-emission enhanced chemical vapour deposition (EEECVD). The feasibility of depositing amorphous hydrogenated carbon films also containing silicon from plasmas of tetramethylsilane or hexamethyldisiloxane has already been shown. In this work, we report the deposition of diverse films from plasmas of tetraethoxysilane (TEOS)-argon mixtures and the characterization of the materials obtained. The effects of changes in the substrate holder bias (V S ) and of the proportion of TEOS in the mixture (X T ) on the chemical structure of the films are examined by infrared-reflection absorption spectroscopy (IRRAS) at near-normal and oblique incidence using unpolarised and p-polarised, light, respectively. The latter is particularly useful in detecting vibrational modes not observed when using conventional near-normal incidence. Elemental analyses of the film were carried out by X-ray photoelectron spectroscopy (XPS), which was also useful in complementary structural investigations. In addition, the dependencies of the deposition rate on V S and X T are presented

Lanthanum titanium perovskite compound: Thin film deposition and high frequency dielectric characterization

International Nuclear Information System (INIS)

Le Paven, C.; Lu, Y.; Nguyen, H.V.; Benzerga, R.; Le Gendre, L.; Rioual, S.; Benzegoutta, D.; Tessier, F.; Cheviré, F.

2014-01-01

Perovskite lanthanum titanium oxide thin films were deposited on (001) MgO, (001) LaAlO 3 and Pt(111)/TiO 2 /SiO 2 /(001)Si substrates by RF magnetron sputtering, using a La 2 Ti 2 O 7 homemade target sputtered under oxygen reactive plasma. The films deposited at 800 °C display a crystalline growth different than those reported on monoclinic ferroelectric La 2 Ti 2 O 7 films. X-ray photoelectron spectroscopy analysis shows the presence of titanium as Ti 4+ ions, with no trace of Ti 3+ , and provides a La/Ti ratio of 1.02. The depositions being performed from a La 2 Ti 2 O 7 target under oxygen rich plasma, the same composition (La 2 Ti 2 O 7 ) is proposed for the deposited films, with an unusual orthorhombic cell and Cmc2 1 space group. The films have a textured growth on MgO and Pt/Si substrates, and are epitaxially grown on LaAlO 3 substrate. The dielectric characterization displays stable values of the dielectric constant and of the losses in the frequency range [0.1–20] GHz. No variation of the dielectric constant has been observed when a DC electric field up to 250 kV/cm was applied, which does not match a classical ferroelectric behavior at high frequencies and room temperature for the proposed La 2 Ti 2 O 7 orthorhombic phase. At 10 GHz and room temperature, the dielectric constant of the obtained La 2 Ti 2 O 7 films is ε ∼ 60 and the losses are low (tanδ < 0.02). - Highlights: • Lanthanum titanium oxide films were deposited by reactive magnetron sputtering. • A La 2 Ti 2 O 7 chemical composition is proposed, with an unusual orthorhombic cell. • At 10 GHz, the dielectric losses are lower than 0.02. • No variation of the dielectric constant is observed under DC electric biasing

The glaciovolcanic evolution of an andesitic edifice, South Crater, Tongariro volcano, New Zealand

Science.gov (United States)

Cole, R. P.; White, J. D. L.; Conway, C. E.; Leonard, G. S.; Townsend, D. B.; Pure, L. R.

2018-02-01

Unusual deposits, mapped and logged in detail, around the summit area of Tongariro volcano, Tongariro Volcanic Centre, New Zealand indicate that the construction and evolution of a substantial portion of this andesitic stratovolcano was beneath a significant ice cap or summit glacier. As the edifice was built under and through the overlying ice, the style of volcanism evolved in a complex history of growth. Initially, a ≥ 100 m thick, widespread hyaloclastite deposit was emplaced within a subglacial, eruption-formed meltwater lake. This was followed by several phases of effusive and explosive eruptions, producing lava flows and primary volcaniclastic deposits emplaced along channels carved into the ice by heated meltwater. The clastic deposits contain quenched bombs and structural features that indicate waterlain transport and emplacement, and soft sediment deformation. Such accumulation of water on a steep-sided edifice without evidence for a subaerial crater lake, along with lava flow features indicating confinement, suggest that a substantial summit glacier was responsible for the production and retention of water, and the architecture of these deposits. Recent studies at nearby Ruapehu volcano have provided good evidence for glaciovolcanic interactions during the last glacial period. However, until now, little was known of the physical lava-ice interactions in the Centre during the last interglacial period and the earlier part of the last glacial period (110-64 ka). These new data support a reinterpretation for the volcanic evolution of the older Tongariro edifice and the emplacement mechanisms of primary volcaniclastic deposits. They also help to constrain local ice thicknesses and extents at the times of eruption. In addition, this study contributes to a sparse global catalogue of glaciovolcanic deposits of andesitic composition, particularly of primary volcaniclastics preserved at mid-latitude stratovolcanoes. The variety of deposit types indicates a

Structural and optical characterization of self-assembled Ge nanocrystal layers grown by plasma-enhanced chemical vapor deposition

NARCIS (Netherlands)

Saeed, S.; Buters, F.; Dohnalova, K.; Wosinski, L.; Gregorkiewicz, T.

2014-01-01

We present a structural and optical study of solid-state dispersions of Ge nanocrystals prepared by plasma-enhanced chemical vapor deposition. Structural analysis shows the presence of nanocrystalline germanium inclusions embedded in an amorphous matrix of Si-rich SiO2. Optical characterization

Preparation, characterization and optical properties of Gadolinium doped ceria thin films by pulsed laser deposition technique

International Nuclear Information System (INIS)

Nagaraju, P.; Vijaya Kumar, Y.; Vishnuvardhan Reddy, C.; Ramana Reddy, M.V.; Phase, D.M; Raghavendra Reddy, V.

2013-01-01

The growth of Gadolinium doped ceria thin films with controlled surface structure for device quality applications presents a significant problem for experimental investigation. In the present study gadolinium doped cerium oxide thin films were prepared by pulsed laser deposition (PLD) and were studied for their surface structure evaluation in relation to the optimized operating conditions during the stage of film preparation. The deposition was made with gadolinium concentration of 10 mole% to ceria pellets. The films were deposited on quartz substrate in the presence of oxygen partial pressure of 1.5 x 10 -3 torr using KrF Excimer laser with laser energy 220 mJ at a substrate temperature 700℃. The effect of annealing temperature on 10 mole% GDC thin film was investigated. The film thickness was measured by using AMBIOS make XP-l stylus profiler. As prepared and annealed thin films were characterized for crystallinity, particle size and orientation by using G.I.XRD. The films were characterized using atomic force microscopy (AFM). The AFM results gave a consistent picture of the evolution of GDC film surface morphologies and microstructures in terms of surface roughness, grain distribution and mean grain size. The optical transmittance spectra was used to determine the optical constants such as optical band gap, refractive index, extinction coefficient of as prepared and annealed thin films. (author)

Role of hydrogen in Sb film deposition and characterization of Sb and GexSby films deposited by cyclic plasma enhanced chemical vapor deposition using metal-organic precursors

International Nuclear Information System (INIS)

Kim, Hyung Keun; Jung, Jin Hwan; Choi, Doo Jin

2012-01-01

To meet increasing demands for chemical vapor deposition methods for high performance phase-change memory, cyclic plasma enhanced chemical vapor deposition of Sb and Ge x Sb y phase-change films and characterization of their properties were performed. Two cycle sequences were designed to investigate the role of hydrogen gas as a reduction gas during Sb film deposition. Hydrogen gas was not introduced into the reaction chamber during the purge step in cycle sequence A and was introduced during the purge step for cycle sequence B. The role of hydrogen gas was investigated by comparing the results obtained from these two cycle sequences and was concluded to exert an effect by a combination of precursor decomposition, surface maintenance as a hydrogen termination agent, and surface etching. These roles of hydrogen gas are discussed through consideration of changes in deposition rates, the oxygen concentration on the surface of the Sb film, and observations of film surface morphology. Based on these results, Ge x Sb y phase-change films were deposited with an adequate flow rate of hydrogen gas. The Ge and Sb composition of the film was controlled with the designed cycle sequences. A strong oxygen affinity for Ge was observed during the X-ray photoelectron spectroscopy analysis of Sb 3d, Sb 4d, and Ge 3d orbitals. Based on the XPS results, the ratios of Ge to Sb were calculated to be Ge 0.32 Sb 0.68 , Ge 0.38 Sb 0.62 , Ge 0.44 Sb 0.56 , Ge 0.51 Sb 0.49 and Ge 0.67 Sb 0.33 for the G1S7, G1S3, G1S2, G1S1, and G2S1 cycles, respectively. Crystal structures of Sb, Ge, and the GeSb metastable phase were observed with various Ge x Sb y film compositions. Sb crystallinity decreased with respect to Ge crystallinity by increasing the Ge fraction. A current–voltage curve was introduced, and an electro-switching phenomenon was clearly generated at a typical voltage, V th . V th values increased in conjunction with an increased proportion of Ge. The Sb crystallinity decrease and V

Deposition and characterization of NbAIN thin films by reactive magnetron sputtering

International Nuclear Information System (INIS)

Carvalho, R.G.; Felix, L.C.; Fernandez, D.A.R.; Fontes Junior, A.S.; Oliveira, G.B.; Tentardini, E.K.

2016-01-01

The objective of this work was to study NbAlN thin films and the influence of variation in the concentration of aluminum in the crystal structure and oxidation resistance of these coatings. The thin films were deposited by reactive magnetron sputtering and characterized by Grazing Incidence X-ray Diffraction (GIXRD), Energy Dispersive Spectroscopy (EDS) and oxidation tests at high temperatures. NbAlN thin films were deposited and present at concentration of 10, 20 and 42 at% Al. The NbAlN crystalline phase obtained was the δ-NbN, however it was observed a shift of the peaks in the patterns obtained GIXRD of regions for larger angles for these samples, indicating the formation of a solid solution. The higher oxidation resistance temperature was 700° C for the sample with 42 in at% Al. From the SEM analysis it was possible to observe the surface of the film after oxidation, all films showed defects, however the amount of such defects was lower in samples with higher aluminum concentrations. (author)

Seismic Characterization of the Terrebonne Mini-basin, a Hydrate Rich Depositional System in the Gulf of Mexico

Science.gov (United States)

Dafov, L. N.; Eze, P. C.; Haines, S. S.; Graham, S. A.; McHargue, T.; Hosford Scheirer, A.

2017-12-01

Natural gas bearing hydrates are a focus of research as a potential source of energy and carbon storage because they occur globally in permafrost regions and marine sediment along every continent. This study focuses on the structural and stratigraphic architecture of the Terrebonne mini-basin, northwest Walker Ridge, Gulf of Mexico, to characterize the depositional architecture and to describe possible migration pathways for petroleum. Questions addressed include: a) continuity of sand layers b) effects of faulting and c) ponding versus fill and spill. To address these questions, seven of forty-two high resolution USGS 2D seismic lines were interpreted and then verified with WesternGeco 3D seismic data, yielding three qualitative models for the depositional environment of hydrate-bearing sand intervals. Deeper hydrate-bearing sand reservoirs were deposited as sheet-like turbidite lobes. Two shallower hydrate-bearing intervals display two possible depositional systems which form reservoirs- 1) sandy to muddy channel sealed laterally by muddy levees with associated sandy crevasse splays, and 2) ponded sandy lobes cut by channels filled with sand lags and mud. Additional observations in the 2D seismic include mass transport deposits and possible contourites. Salt movement facilitated mini-basin formation which was then ponded by sediment and followed by episodes of fill-and-spill and erosion. These seismic interpretations indicate periodic salt uplift. Overturn of salt along the northwestern edge of the basin resulted in thrust faults. The faults and erosional surfaces act as seals to reservoirs. The greatest volume of sandy reservoir potential occurs in sheet-like turbidite lobes with high lateral continuity, which facilitates updip migration of deep-sourced thermogenic gas along bedding surfaces. Channel levees serve as lateral seals to gas hydrate reservoirs, whereas faults, erosional surfaces, and shales provide vertical seals. Characterization of the Terrebonne

Investigation on characterization of Ereen coal deposit

OpenAIRE

S. Jargalmaa; B. Purevsuren; Ya. Davaajav; B. Avid; B. Bat-Ulzii; B. Ochirhuyag

2016-01-01

The Ereen coal deposit is located 360 km west from Ulaanbaatar and 95 km from Bulgan town. The coal reserve of this deposit is approximately 345.2 million tons. The Ereen coal is used directly for the Erdenet power plant for producing of electricity and heat. The utilization of this coal for gas and liquid product using gasification and pyrolysis is now being considered. The proximate and ultimate analysis show that the Ereen coal is low rank D mark hard coal, which corresponds to subbitumino...

Characterization of spray deposition and drift from a low drift nozzle for aerial application at different application altitudes

Science.gov (United States)

A complex interaction of controllable and uncontrollable factors is involved in aerial application of crop production and protection materials. Although it is difficult to completely characterize spray deposition and drift, these important factors can be estimated with appropriate sampling protocol ...

TiN films by Atomic Layer Deposition: Growth and electrical characterization down to sub-nm thickness

NARCIS (Netherlands)

Van Hao, B.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.

2012-01-01

This study reports on the growth and characterization of TiN thib films obtained by atomic layer deposition at 350-425 ◦C. We observe a growth of the continuous layers from the very beginning of the process, i.e. for a thickness of 0.65 nm, which is equivalent to 3 monolayers of TiN. The film growth

Characterization of Cr2O3 thin films obtained by chemical vapor deposition

International Nuclear Information System (INIS)

Pillis, M.F.; Galego, E.; Serna, M.M.; Correa, O.V.; Ramanathan, L.V.; Franco, A.C.

2010-01-01

The goal of this work was the synthesis and characterization of Cr 2 O 3 thin films, obtained by chemical vapor deposition, using chromium acetylacetonate as chromium precursor. The growth of the films was carried out in a conventional horizontal MOCVD equipment, under pressures varying from 2 to 10 mbar, and temperature of 600 deg C. It was observed that the growth of the films only occurs when oxygen is present in the atmosphere. Under growth pressures of 2 and 5 mbar the growth takes place but under 10 mbar of pressure the precursor is dragged and the growth does not occur. The characterization of the films was performed by using scanning electron microscopy and X-ray diffraction. The films presented a columnar structure, and thickness varying from 40 to 250 nm. The influence of some process parameters is discussed. (author)

Deposition and Characterization of TRISO Coating Layers

International Nuclear Information System (INIS)

Kim, D. K.; Choi, D. J.; Lee, H. K.; Kim, J. K.; Kim, J. H.; Chun, J. H.

2007-03-01

Zirconium carbide has been chosen and studied as an advanced material of silicon carbide. In order to collect data on the basic properties and characteristics of Zirconium carbide, studies have been conducted using various methods. As a result of chemically vapor deposed subliming zirconium tetrachloride(ZrCl4) and using methane(CH4) as a source in hydrogen atmosphere, graphite film is deposited.. Zirconium carbide was deposited on the sample where silicon carbide was deposited on a graphite substrate using Zirconium sponge as a Zirconium source. In terms of physical characteristics, the deposited Zirconium carbide showed higher strength, but slightly lower elastic modulus than silicon carbide. In order to evaluate the mechanical properties of a coating layer in pre-irradiation step, internal pressure induced method and direct strength measurement method is carried out. In the internal pressure induced method, in order to produce the requirement pressure, pressure media is used. In the direct strength measurement method, the indentation experiment that indent on a hemisphere shell with plate indenter is conducted. For this method, the finite element analysis is used and the analysis is verified by indentation experiments. To measure the strength of TRISO particle SiC coating, SiC hemisphere shell is performed through grinding and heat treatment. Through the finite element analysis, strength evaluation equation is suggested. Using suggested equation, Strength evaluation is performed and the strength value shows 1025MPa as a result of statistical analysis

Deposition and Characterization of TRISO Coating Layers

Energy Technology Data Exchange (ETDEWEB)

Kim, D. K.; Choi, D. J.; Lee, H. K.; Kim, J. K.; Kim, J. H.; Chun, J. H. [KAIST, Daejeon (Korea, Republic of)

2007-03-15

Zirconium carbide has been chosen and studied as an advanced material of silicon carbide. In order to collect data on the basic properties and characteristics of Zirconium carbide, studies have been conducted using various methods. As a result of chemically vapor deposed subliming zirconium tetrachloride(ZrCl4) and using methane(CH4) as a source in hydrogen atmosphere, graphite film is deposited.. Zirconium carbide was deposited on the sample where silicon carbide was deposited on a graphite substrate using Zirconium sponge as a Zirconium source. In terms of physical characteristics, the deposited Zirconium carbide showed higher strength, but slightly lower elastic modulus than silicon carbide. In order to evaluate the mechanical properties of a coating layer in pre-irradiation step, internal pressure induced method and direct strength measurement method is carried out. In the internal pressure induced method, in order to produce the requirement pressure, pressure media is used. In the direct strength measurement method, the indentation experiment that indent on a hemisphere shell with plate indenter is conducted. For this method, the finite element analysis is used and the analysis is verified by indentation experiments. To measure the strength of TRISO particle SiC coating, SiC hemisphere shell is performed through grinding and heat treatment. Through the finite element analysis, strength evaluation equation is suggested. Using suggested equation, Strength evaluation is performed and the strength value shows 1025MPa as a result of statistical analysis.

Fabrication and characterization of implantable and flexible nerve cuff electrodes with Pt, Ir and IrOx films deposited by RF sputtering

International Nuclear Information System (INIS)

Lee, Soo Hyun; Jung, Jung Hwan; Chae, Youn Mee; Kang, Ji Yoon; Suh, Jun-Kyo Francis

2010-01-01

This paper presents the fabrication and characterization of implantable and flexible nerve cuff electrodes for neural interfaces using the conventional BioMEMS technique. In order to fabricate a flexible nerve electrode, polyimide (PI) was chosen as the substrate material. Then, nerve electrodes were thermally re-formed in a cuff shape so as to increase the area in which the charges were transferred to the nerve. Platinum (Pt), iridium (Ir) and iridium oxide (IrO x ) films, which were to serve as conducting materials for the nerve electrodes, were deposited at different working pressures by RF magnetron sputtering. The electrochemical properties of the deposited films were characterized by electrochemical impedance spectroscopy (EIS). The charge delivery capacities of the films were recorded and calculated by cyclic voltammetry (CV). The deposited films of Pt, Ir and IrO x have strong differences in electrochemical properties, which depend on the working pressure of sputter. Each film deposited at 30 mTorr of working pressure shows the highest value of charge delivery capacity (CDC). For the IrO x films, the electrochemical properties were strongly affected by the working pressure as well as the Ar:O 2 gas ratio. The IrO x film deposited with an Ar:O 2 gas ratio of 8:1 showed the highest CDC of 59.5 mC cm −2 , which was about five times higher than that of films deposited with a 1:1 gas ratio.

Characterization of Niobium Oxide Films Deposited by High Target Utilization Sputter Sources

International Nuclear Information System (INIS)

Chow, R; Ellis, A D; Loomis, G E; Rana, S I

2007-01-01

High quality, refractory metal, oxide coatings are required in a variety of applications such as laser optics, micro-electronic insulating layers, nano-device structures, electro-optic multilayers, sensors and corrosion barriers. A common oxide deposition technique is reactive sputtering because the kinetic mechanism vaporizes almost any solid material in vacuum. Also, the sputtered molecules have higher energies than those generated from thermal evaporation, and so the condensates are smoother and denser than those from thermally-evaporated films. In the typical sputtering system, target erosion is a factor that drives machine availability. In some situations such as nano-layered capacitors, where the device's performance characteristics depends on thick layers, target life becomes a limiting factor on the maximizing device functionality. The keen interest to increase target utilization in sputtering has been addressed in a variety of ways such as target geometry, rotating magnets, and/or shaped magnet arrays. Also, a recent sputtering system has been developed that generates a high density plasma, directs the plasma beam towards the target in a uniform fashion, and erodes the target in a uniform fashion. The purpose of this paper is to characterize and compare niobia films deposited by two types of high target utilization sputtering sources, a rotating magnetron and a high density plasma source. The oxide of interest in this study is niobia because of its high refractive index. The quality of the niobia films were characterized spectroscopically in optical transmission, ellipsometrically, and chemical stoichiometry with X-ray photo-electron spectroscopy. The refractive index, extinction coefficients, Cauchy constants were derived from the ellipsometric modeling. The mechanical properties of coating density and stress are also determined

Characterization of chemically deposited low-cost 2-6 thin films solar cells : modifying effects with catalytic silicotungstic acid (STA)

Energy Technology Data Exchange (ETDEWEB)

Petuenju, E.N.; Savadogo, O. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada). Laboratoire de nouveaux materiaux pour l' energie et l' electrochimie

2008-07-01

This paper described some properties of cadmium sulphide (CdS) thin films that were chemically deposited on a silicon wafer for solar cell and optoelectronic applications. The as-deposited films were thermally annealed and characterized through structural, electrical, optical, and spectroscopic methods. The modifying effects of silicotungstic acid (STA) showed promising characteristics for various applications, including X- and gamma-ray detector devices. The films were characterized by X-rays Photoelectron Spectroscopy, Scanning Electron Microscopy, X-ray Diffraction, and Photoluminescence. Ellipsometry measurements were used to determine the thickness of the sample. The study showed that there is no significant effect of the addition of 10-4 M of STA on the thickness of the film. This might be due to the low concentration of STA. No significant difference was noted for samples deposited with and without STA. In both cases the crystallite size of the sample was estimated to be lower than 1.5 microns. The CdS/Si and CdS(STA)/Si samples were annealed at 360 degrees C for 12 hours. The samples prepared with and without STA had the same structure. CdS deposited without and STA exhibited a mixed hexagonal and cubic structure, most likely because the annealing temperature of the sample was very close to the transition temperature of the cubic structure to the hexagonal structure. 3 refs., 1 tab., 3 figs.

Characterization of Reagent Pencils for Deposition of Reagents onto Paper-Based Microfluidic Devices

Directory of Open Access Journals (Sweden)

Cheyenne H. Liu

2017-08-01

Full Text Available Reagent pencils allow for solvent-free deposition of reagents onto paper-based microfluidic devices. The pencils are portable, easy to use, extend the shelf-life of reagents, and offer a platform for customizing diagnostic devices at the point of care. In this work, reagent pencils were characterized by measuring the wear resistance of pencil cores made from polyethylene glycols (PEGs with different molecular weights and incorporating various concentrations of three different reagents using a standard pin abrasion test, as well as by measuring the efficiency of reagent delivery from the pencils to the test zones of paper-based microfluidic devices using absorption spectroscopy and digital image colorimetry. The molecular weight of the PEG, concentration of the reagent, and the molecular weight of the reagent were all found to have an inverse correlation with the wear of the pencil cores, but the amount of reagent delivered to the test zone of a device correlated most strongly with the concentration of the reagent in the pencil core. Up to 49% of the total reagent deposited on a device with a pencil was released into the test zone, compared to 58% for reagents deposited from a solution. The results suggest that reagent pencils can be prepared for a variety of reagents using PEGs with molecular weights in the range of 2000 to 6000 g/mol.

Lanthanum titanium perovskite compound: Thin film deposition and high frequency dielectric characterization

Energy Technology Data Exchange (ETDEWEB)

Le Paven, C., E-mail: claire.lepaven@univ-rennes1.fr [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Lu, Y. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Nguyen, H.V. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); CEA LETI, Minatec Campus, 38054 Grenoble (France); Benzerga, R.; Le Gendre, L. [Institut d' Electronique et de Télécommunications de Rennes (IETR, UMR-CNRS 6164), Equipe Matériaux Fonctionnels, IUT Saint Brieuc, Université de Rennes 1, 22000 Saint Brieuc (France); Rioual, S. [Laboratoire de Magnétisme de Brest (EA CNRS 4522), Université de Bretagne Occidentale, 29000 Brest (France); Benzegoutta, D. [Institut des Nanosciences de Paris (INSP, UMR CNRS 7588), Université Pierre et Marie Curie, 75005 Paris (France); Tessier, F.; Cheviré, F. [Institut des Sciences Chimiques de Rennes (ISCR, UMR-CNRS 6226), Equipe Verres et Céramiques, Université de Rennes 1, 35000 Rennes (France); and others

2014-02-28

Perovskite lanthanum titanium oxide thin films were deposited on (001) MgO, (001) LaAlO{sub 3} and Pt(111)/TiO{sub 2}/SiO{sub 2}/(001)Si substrates by RF magnetron sputtering, using a La{sub 2}Ti{sub 2}O{sub 7} homemade target sputtered under oxygen reactive plasma. The films deposited at 800 °C display a crystalline growth different than those reported on monoclinic ferroelectric La{sub 2}Ti{sub 2}O{sub 7} films. X-ray photoelectron spectroscopy analysis shows the presence of titanium as Ti{sup 4+} ions, with no trace of Ti{sup 3+}, and provides a La/Ti ratio of 1.02. The depositions being performed from a La{sub 2}Ti{sub 2}O{sub 7} target under oxygen rich plasma, the same composition (La{sub 2}Ti{sub 2}O{sub 7}) is proposed for the deposited films, with an unusual orthorhombic cell and Cmc2{sub 1} space group. The films have a textured growth on MgO and Pt/Si substrates, and are epitaxially grown on LaAlO{sub 3} substrate. The dielectric characterization displays stable values of the dielectric constant and of the losses in the frequency range [0.1–20] GHz. No variation of the dielectric constant has been observed when a DC electric field up to 250 kV/cm was applied, which does not match a classical ferroelectric behavior at high frequencies and room temperature for the proposed La{sub 2}Ti{sub 2}O{sub 7} orthorhombic phase. At 10 GHz and room temperature, the dielectric constant of the obtained La{sub 2}Ti{sub 2}O{sub 7} films is ε ∼ 60 and the losses are low (tanδ < 0.02). - Highlights: • Lanthanum titanium oxide films were deposited by reactive magnetron sputtering. • A La{sub 2}Ti{sub 2}O{sub 7} chemical composition is proposed, with an unusual orthorhombic cell. • At 10 GHz, the dielectric losses are lower than 0.02. • No variation of the dielectric constant is observed under DC electric biasing.

Deposition studies and coordinated characterization of MOCVD YBCO films on IBAD-MgO templates

International Nuclear Information System (INIS)

Aytug, T; Paranthaman, M; Heatherly, L; Zuev, Y; Zhang, Y; Kim, K; Goyal, A; Maroni, V A; Chen, Y; Selvamanickam, V

2009-01-01

A recently installed research-scale metal-organic chemical vapor deposition (MOCVD) system at Oak Ridge National Laboratory, provided by SuperPower, Inc., has been used to investigate processing variables for MOCVD YBCO precursors and trends in the resulting properties. Systematic studies of YBCO film growth on LaMnO 3 /IBAD-MgO templates were carried out by optimizing deposition temperature and oxygen flow rate. Microstructural and superconducting properties of the YBCO films were analyzed by x-ray diffraction, scanning electron microscopy and transport measurements. The identification of intermediate phases formed during the YBCO precursor transformation was investigated by coordinated reel-to-reel Raman microprobe analysis. With this combination of various characterization techniques, an improved understanding of the growth characteristics of MOCVD YBCO films was established. Finally, critical current densities greater than 2 MA cm -2 for film thicknesses of 0.8 μm were demonstrated.

Deposition studies and coordinated characterization of MOCVD YBCO films on IBAD-MgO templates

Energy Technology Data Exchange (ETDEWEB)

Aytug, T; Paranthaman, M [Oak Ridge National Laboratory, Chemical Sciences Division, Oak Ridge, TN 37831 (United States); Heatherly, L; Zuev, Y; Zhang, Y; Kim, K; Goyal, A [Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37831 (United States); Maroni, V A [Argonne National Laboratory, Chemical Sciences and Engineering Division, Argonne, IL 60439 (United States); Chen, Y; Selvamanickam, V [SuperPower, Incorporated, 450 Duane Avenue, Schenectady, NY 12304 (United States)], E-mail: aytugt@ornl.gov

2009-01-15

A recently installed research-scale metal-organic chemical vapor deposition (MOCVD) system at Oak Ridge National Laboratory, provided by SuperPower, Inc., has been used to investigate processing variables for MOCVD YBCO precursors and trends in the resulting properties. Systematic studies of YBCO film growth on LaMnO{sub 3}/IBAD-MgO templates were carried out by optimizing deposition temperature and oxygen flow rate. Microstructural and superconducting properties of the YBCO films were analyzed by x-ray diffraction, scanning electron microscopy and transport measurements. The identification of intermediate phases formed during the YBCO precursor transformation was investigated by coordinated reel-to-reel Raman microprobe analysis. With this combination of various characterization techniques, an improved understanding of the growth characteristics of MOCVD YBCO films was established. Finally, critical current densities greater than 2 MA cm{sup -2} for film thicknesses of 0.8 {mu}m were demonstrated.

Characterization of a coal tailing deposit for zero waste mine in the Brazilian coal field of Santa Catarina

International Nuclear Information System (INIS)

Amaral Filho, J.R.; Schneider, I.A.H.; Tubino, R.M.C.; Brum de, I.A.S.; Miltzarek, G.; Sampaio, C.H.

2010-01-01

Coal tailings deposits in Brazil are occupying large areas of land while also generating acid mine drainage (AMD) that includes heavy metals. This paper described an analytical study of a typical coal tailings deposit. The study objective was to separate low density, intermediate density, and high density fractions for future reuse. Particle size analysis, disymmetric studies, X-ray diffraction, and tests conducted to determine ash, total sulphur, and acid bases were conducted in order to characterize the coal tailings samples. Results of the study demonstrated a size distribution of 67 percent coarse, 14 percent fine, and 19 percent ultra-fine particles. The gravimetric concentration method was used to recover 34.2 percent of the total deposit for future energy use. Approximately 9.2 percent of the remaining deposit was a pyrite concentrate. The acid generating potential of the remaining materials was reduced by approximately 60 percent. 9 refs., 1 tab., 2 figs.

Microstructural characterization of chemical bath deposited and sputtered Zn(O,S) buffer layers

International Nuclear Information System (INIS)

Gautron, E.; Buffière, M.; Harel, S.; Assmann, L.; Arzel, L.; Brohan, L.; Kessler, J.; Barreau, N.

2013-01-01

The present work aims at investigating the microstructure of Zn(O,S) buffer layers relative to their deposition route, namely either chemical bath deposition (CBD) or RF co-sputtering process (PVD) under pure Ar. The core of the study consists of cross-sectional transmission electron microscopy (TEM) characterization of the differently grown Zn(O,S) thin films on co-evaporated Cu(In,Ga)Se 2 (CIGSe) absorbers. It shows that the morphology of Zn(O,S) layer deposited on CIGSe using CBD process is made of a thin layer of well oriented ZnS sphalerite-(111) and/or ZnS wurtzite-(0002) planes parallel to CIGSe chalcopyrite-(112) planes at the interface with CIGSe followed by misoriented nanometer-sized ZnS crystallites in an amorphous phase. As far as (PVD)Zn(O,S) is concerned, the TEM analyses reveal two different microstructures depending on the S-content in the films: for [S] / ([O] + [S]) = 0.6, the buffer layer is made of ZnO zincite and ZnS wurtzite crystallites grown nearly coherently to each other, with (0002) planes nearly parallel with CIGSe-(112) planes, while for [S] / ([O] + [S]) = 0.3, it is made of ZnO zincite type crystals with O atoms substituted by S atoms, with (0002) planes perfectly aligned with CIGSe-(112) planes. Such microstructural differences can explain why photovoltaic performances are dependent on the Zn(O,S) buffer layer deposition route. - Highlights: ► Zn(O,S) layers were grown by chemical bath (CBD) or physical vapor (PVD) deposition. ► For CBD, a 3 nm ZnS layer is followed by ZnS nano-crystallites in an amorphous phase. ► For PVD with [S] / ([O] + [S]) = 0.3, the layer has a Zn(O,S) zincite structure. ► For PVD with [S] / ([O] + [S]) = 0.6, ZnS wurtzite and ZnO zincite phases are mixed

The Stratigraphy and Lithofacies of the Paleoproterozoic Volcaniclastic Sequences in the Cape Three Points Area- Akodda section of the Southern in Ashanti Belt in the Birimian of southwest Ghana

Science.gov (United States)

Yoshimaru, S.; Kiyokawa, S.; Ito, T.; Ikehara, M.; Nyame, F. K.; Tetteh, G. M.

2015-12-01

volcaniclastic rocks in an oceanic island arc around the West African Craton. Preliminary δ13C analysis gave values of -23.7~ -36.5 ‰ for black shale occupying the middle to upper part of the whole section. The very light carbon isotope ratios suggest deposition of the black shale under highly euxinic conditions like today's Black sea.

Thermal plasma spheroidization and spray deposition of barium titanate powder and characterization of the plasma sprayable powder

Energy Technology Data Exchange (ETDEWEB)

Pakseresht, A.H., E-mail: amirh_pak@yahoo.com [Department of Ceramics, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Rahimipour, M.R. [Department of Ceramics, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Vaezi, M.R. [Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box 31787-316, Karaj (Iran, Islamic Republic of); Salehi, M. [Department of Materials Engineering, Isfahan University of Technology, P.O. Box 84156-83111, Isfahan (Iran, Islamic Republic of)

2016-04-15

In this paper, atmospheric plasma spray method was used to produce dense plasma sprayable powder and thick barium titanate film. In this regard, the commercially feedstock powders were granulated and spheroidized by the organic binder and the thermal spray process, respectively. Scanning electron microscopy was used to investigate the microstructure of the produced powders and the final deposits. X-ray diffraction was also implemented to characterize phase of the sprayed powder. The results indicated that spheroidized powder had suitable flowability as well as high density. The micro-hardness of the film produced by the sprayed powders was higher than that of the film deposited by the irregular granules. Additionally, relative permittivity of the films was increased by decreasing the defects from 160 to 293 for film deposited using spheroidized powder. The reduction in the relative permittivity of deposits, in comparison with the bulk material, was due to the existence of common defects in the thermal spray process. - Highlights: • We prepare sprayable BaTiO{sub 3} powder with no or less inside voids for plasma spray application for first time. • The sprayable powder has good flow characteristics and high density. • Powder spheroidization via plasma spray improves the hardness and dielectric properties of the deposited film.

Thermal plasma spheroidization and spray deposition of barium titanate powder and characterization of the plasma sprayable powder

International Nuclear Information System (INIS)

Pakseresht, A.H.; Rahimipour, M.R.; Vaezi, M.R.; Salehi, M.

2016-01-01

In this paper, atmospheric plasma spray method was used to produce dense plasma sprayable powder and thick barium titanate film. In this regard, the commercially feedstock powders were granulated and spheroidized by the organic binder and the thermal spray process, respectively. Scanning electron microscopy was used to investigate the microstructure of the produced powders and the final deposits. X-ray diffraction was also implemented to characterize phase of the sprayed powder. The results indicated that spheroidized powder had suitable flowability as well as high density. The micro-hardness of the film produced by the sprayed powders was higher than that of the film deposited by the irregular granules. Additionally, relative permittivity of the films was increased by decreasing the defects from 160 to 293 for film deposited using spheroidized powder. The reduction in the relative permittivity of deposits, in comparison with the bulk material, was due to the existence of common defects in the thermal spray process. - Highlights: • We prepare sprayable BaTiO_3 powder with no or less inside voids for plasma spray application for first time. • The sprayable powder has good flow characteristics and high density. • Powder spheroidization via plasma spray improves the hardness and dielectric properties of the deposited film.

Structural and electrical characterizations of BiFeO{sub 3} capacitors deposited by sol–gel dip coating technique

Energy Technology Data Exchange (ETDEWEB)

Cetinkaya, Ali Osman, E-mail: cetinkayaaliosman@gmail.com [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Center for Nuclear Radiation Detector Research and Applications, 14280 Bolu (Turkey); Kaya, Senol; Aktag, Aliekber [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Center for Nuclear Radiation Detector Research and Applications, 14280 Bolu (Turkey); Budak, Erhan [Chemistry Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Yilmaz, Ercan [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Center for Nuclear Radiation Detector Research and Applications, 14280 Bolu (Turkey)

2015-09-01

Bismuth ferrite (BiFeO{sub 3}) thin films were deposited by sol–gel dip coating (SGDC) technique on Si-P(100) and glass substrates to investigate the structural and electrical characteristics. The aluminum (Al) metal contacts were formed on the samples deposited on the Si-P(100) to fabricate metal-oxide-semiconductor (MOS) capacitors. The fabricated MOS structures were characterized electrically by capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements. The structural characterizations were performed by X-ray diffraction technique and scanning electron microscopy. The compositions of the films were investigated by energy-dispersive X-ray spectroscopy. The results exhibit that pure rhombohedral perovskite phase films were fabricated without any elemental contamination. Average grain sizes of the BiFeO{sub 3} deposited on silicon and glass wafers were found to be about 34,50 and 30,00 nm, respectively. In addition, while the thin films deposited on glass substrate exhibit porous surface, those deposited on Si-P(100) wafers exhibit dense microstructure with a homogenous surface. Moreover, the C–V and G/ω–V characteristics are sensitive to applied voltage frequency due to frequency dependent charges (N{sub ss}) and series resistance (R{sub s}). The peak values of R{sub s} have been decreased from 2,6 kΩ to 40 Ω, while N{sub ss} is varied from 6,57 × 10{sup 12} to 3,68 × 10{sup 12} eV{sup −1} cm{sup −2} with increasing in frequency. Consequently, pure phase polycrystalline BiFeO{sub 3} thin films were fabricated successfully by SGDC technique and BiFeO{sub 3} dielectric layer exhibits stable insulation characteristics. - Highlights: • Bismuth ferrite thin films were deposited onto silicon and glass substrates by sol–gel. • Structural and electrical properties of fabricated films have been investigated. • Pure rhombohedral perovskite phase films without any contamination were deposited. • Series resistance and interface

Deposition and characterization of single magnetron deposited Fe:SnO{sub x} coatings

Energy Technology Data Exchange (ETDEWEB)

Kormunda, Martin, E-mail: martin.kormunda@ujep.cz [J.E. Purkinje University, Faculty of Science, Department of Physics, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic); Fischer, Daniel; Hertwig, Andreas; Beck, Uwe [BAM Federal Institute for Materials Research and Testing, Division 6 4 Surface Technologies, Unter den Eichen 44-46, 12203 Berlin (Germany); Sebik, Matej; Pavlik, Jaroslav [J.E. Purkinje University, Faculty of Science, Department of Physics, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic); Esser, Norbert [Leibniz-Institut für Analytische Wissenschaften — ISAS e.V., Department Berlin, Schwarzschildstr. 12, 12489 Berlin (Germany)

2015-11-30

Coatings deposited by magnetron co-sputtering from a single RF magnetron with a ceramic SnO{sub 2} target with iron inset in argon plasma were studied. The mass spectra of the process identified Sn{sup +} and SnO{sup +} species as the dominant species sputtered from the target, but no SnO{sub 2}{sup +} species were detected. The dominant positive ions in argon plasma are Ar{sup +} species. The only detected negative ions were O{sup −}. Sputtered neutral tin related species were not detected. Iron related species were also not detected because their concentration is below the detection limit. The concentration of iron dopant in the tin oxide coatings was controlled by the RF bias applied on the substrate holder while the discharge pressure also has some influence. The iron concentration was in the range from 0.9 at.% up to 19 at.% increasing with the substrate bias while the sheet resistivity decreases. The stoichiometry ratio of O/(Sn + Fe) in the coatings increased from 1.7 up to 2 in dependence on the substrate bias from floating bias (− 5 V) up to − 120 V of RF self-bias, respectively. The tin in the coatings was mainly bonded in Sn{sup 4+} state and iron was mainly in Fe{sup 2+} state when other tin bonding states were detected only in a small amounts. Iron bonding states in contrary to elemental compositions of the coatings were not influenced by the RF bias applied on the substrate. The coatings showed high transparency in the visible spectral range. However, an increased metallic behavior could be detected by using a higher RF bias for the deposition. The X-ray diffraction patterns and electron microscopy pictures made on the coatings confirmed the presence of an amorphous phase. - Highlights: • RF magnetron sputtering of SnO{sub 2} target with Fe inset in argon investigated by mass spectrometry • Optical properties of Fe doped SnO{sub x} coatings characterized • Analyses of overlapped XPS peaks at a spectrum from Fe doped SnO{sub x} coatings �

Fabrication and characterization of vacuum deposited fluorescein thin films

Energy Technology Data Exchange (ETDEWEB)

Jalkanen, Pasi, E-mail: pasi.jalkanen@gmail.co [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kulju, Sampo, E-mail: sampo.j.kulju@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Arutyunov, Konstantin, E-mail: konstantin.arutyunov@jyu.f [University of Jyvaeskylae, Department of Physics, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Antila, Liisa, E-mail: liisa.j.antila@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Myllyperkioe, Pasi, E-mail: pasi.myllyperkio@jyu.f [University of Jyvaeskylae, Department of Chemistry, Nanoscience center (NSC) P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Ihalainen, Teemu, E-mail: teemu.o.ihalainen@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Kaeaeriaeinen, Tommi, E-mail: tommi.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Kaeaeriaeinen, Marja-Leena, E-mail: marja-leena.kaariainen@lut.f [Lappeenranta University of Technology, ASTRal, P.O. Box 181, FI-50101 Mikkeli (Finland); Korppi-Tommola, Jouko, E-mail: jouko.korppi-tommola@jyu.f [University of Jyvaeskylae, Department of Biology, Nanoscience center (NSC), P.O. Box 35, FI-40014 Jyvaeskylae (Finland)

2011-03-31

Simple vacuum evaporation technique for deposition of dyes on various solid surfaces has been developed. The method is compatible with conventional solvent-free nanofabrication processing enabling fabrication of nanoscale optoelectronic devices. Thin films of fluorescein were deposited on glass, fluorine-tin-oxide (FTO) coated glass with and without atomically layer deposited (ALD) nanocrystalline 20 nm thick anatase TiO{sub 2} coating. Surface topology, absorption and emission spectra of the films depend on their thickness and the material of supporting substrate. On a smooth glass surface the dye initially forms islands before merging into a uniform layer after 5 to 10 monolayers. On FTO covered glass the absorption spectra are similar to fluorescein solution in ethanol. Absorption spectra on ALD-TiO{sub 2} is red shifted compared to the film deposited on bare FTO. The corresponding emission spectra at {lambda} = 458 nm excitation show various thickness and substrate dependent features, while the emission of films deposited on TiO{sub 2} is quenched due to the effective electron transfer to the semiconductor conduction band.

Iron oxi-hydroxides characterization and associated elements (S, Se, As, Mo, V, Zr) in the redox environments favorable for uranium deposits

International Nuclear Information System (INIS)

Pons, Tony

2015-01-01

This work presents a multi-scale and a multi-technical study for the characterization of iron oxi-hydroxides in three uranium-type deposits and host rock. The choice of sites has focused on a roll front deposit: Zoovch Ovoo in a Cretaceous basin of East Gobi (Mongolia); a tectonic-lithological type: Akola/Ebba in Tim Mersoi basin (Niger) and a Proterozoic unconformity type: Kiggavik in Thelon basin (Canada). A new approach has been implemented to characterize the iron oxi-hydroxides on macroscopic samples: field infrared spectroscopy using the ASD TerraSpec spectrometer. From the original indexes calculated on the spectra, it was possible both to characterize the iron oxi-hydroxides; only hematite and goethite were identified in the different parts of oxidized uranium fronts, and visualize the alteration zonation along the redox front. In addition, the visible part of spectrum was used to quantify the color of samples through the IHS system parameters (Intensity - Hue - Saturation) and the Munsell system. The color setting of the study identified a specific hue for mineralized samples studied: a mixture of yellow and red (2.5 to 10 Yr in Munsell notation). At the crystals scale, the iron-hydroxides were characterized by μ-Raman spectroscopy. The study highlighted a difference in crystallinity of hematite crystals in different fields. From a morphological point of view, the crystals of goethite in the Zoovch Ovoo deposit, is only authigenic iron oxi-hydroxides described in this uranium front, are twinned in the form of six-pointed star, reflecting a low crystallization temperature, compared to Niger and Kiggavik deposits. This crystallization is mainly controlled by the availability of Fe(III) ions in the fluid, released by pyrite dissolution in an oxidizing environment and pH. From a chemical point of view, iron oxi-hydroxides record the fluid passage owing their uranium content. Secondly, the composition in trace elements marks the type of deposit, for example

Ultraviolet optical properties of aluminum fluoride thin films deposited by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Hennessy, John, E-mail: john.j.hennessy@jpl.nasa.gov; Jewell, April D.; Balasubramanian, Kunjithapatham; Nikzad, Shouleh [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

2016-01-15

Aluminum fluoride (AlF{sub 3}) is a low refractive index material with promising optical applications for ultraviolet (UV) wavelengths. An atomic layer deposition process using trimethylaluminum and anhydrous hydrogen fluoride has been developed for the deposition of AlF{sub 3} at substrate temperatures between 100 and 200 °C. This low temperature process has resulted in thin films with UV-optical properties that have been characterized by ellipsometric and reflection/transmission measurements at wavelengths down to 200 nm. The optical loss for 93 nm thick films deposited at 100 °C was measured to be less than 0.2% from visible wavelengths down to 200 nm, and additional microstructural characterization demonstrates that the films are amorphous with moderate tensile stress of 42–105 MPa as deposited on silicon substrates. X-ray photoelectron spectroscopy analysis shows no signature of residual aluminum oxide components making these films good candidates for a variety of applications at even shorter UV wavelengths.

Regional stratigraphy, sedimentology, and tectonic significance of Oligocene-Miocene sedimentary and volcanic rocks, northern Baja California, Mexico

Science.gov (United States)

Dorsey, Rebecca J.; Burns, Beverly

1994-01-01

Upper Oligocene (?) to middle Miocene sedimentary and volcanic rocks in northern Baja California were deposited along the western margin of North America during subduction of the Guadalupe plate and southward migration of the Rivera Triple Junction. Regional mapping and compilation of stratigraphic data reveal a sequence of three regionally traceable stratigraphic units. (1) Oligocene (?) to lower Miocene Mesa Formation: basal quartz-rich fluvial sandstone, grus, conglomerate, and accessory facies, whose detrital compositions reflect the composition of local pre-Tertiary basement rock. (2) Lower to middle Miocene Comondú Formation: laterally variable sequence of volcaniclastic conglomerate, breccia, sandstone, tuff and minor volcanic flow units. (3) Widespread mesa-capping rhyolite tuff, typically welded and crystal-rich, probably upper Miocene in age. The Mesa Formation overlies a highly irregular and deeply dissected erosional surface developed on pre-Tertiary basement rock. The shift from pre-Mesa erosion to widespread (though localized) deposition and valley-filling records the final phase of late Cretaceous to middle Tertiary regional subsidence and eastward transgression that resulted from slow cooling and thermal contraction of Cretaceous arc crust during a temporal gap in magmatic activity along the western Cordilleran margin. Nonmarine sediments of the Mesa Formation were deposited in small, steep-walled paleovalleys and basins that gradually filled and evolved to form through-going, low-energy ephemeral stream systems. The gradational upward transition from the Mesa to Comondú Formation records the early to middle Miocene onset of subduction-related arc magmatism in eastern Baja California and related westward progradation of alluvial volcaniclastic aprons shed from high-standing eruptive volcanic centers. Pre-existing streams were choked with the new influx of volcanic detritus, causing the onset of rapid sediment deposition by stream flows and dilute

Hydrothermal Fe-Si-Mn oxide deposits from the Central and South Valu Fa Ridge, Lau Basin

International Nuclear Information System (INIS)

Sun Zhilei; Zhou Huaiyang; Yang Qunhui; Sun Zhixue; Bao Shenxu; Yao Huiqiang

2011-01-01

Highlights: → The Fe-Mn crust in the HHF has seawater contribution, whereas the Fe-Si oxide in the MHF is dominated by hydrothermal fluid → The Nd isotope of diffuse flow Fe-Si-Mn deposits indicates the obvious hydrothermal origin. → The Mn/Fe ratio in hydrothermal deposit may be a good indicator of propagating activities of the Valu Fa Ridge. - Abstract: A series of samples from the Hine Hina hydrothermal field (HHF) and the Mariner hydrothermal field (MHF) in the Central and Southern Valu Fa Ridge (VFR), Lau Basin were examined to explain the source origin and formation of the hydrothermal Fe-Si-Mn oxide deposits. The mineralogy was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Moessbauer spectroscopy, and energy-dispersive spectroscopy (EDS). For the Fe-Mn oxide crusts in the HHF, varying amounts of volcanic fragments and some seawater contributions were recognized, along with higher concentrations of Mn, Al, Co, Ni, Zn, Sr, Mo, elevated ΣREE and negative Ce anomalies. In contrast, the Si-rich oxide samples of the MHF were enriched in Cu, Pb and Ba, indicative of proximity to a hydrothermal jet. Moreover, conductive cooling of hydrothermal fluid evoked the Si-rich deposit formation in the MHF. The Sr, Nd and Pb isotope data provided further constraints regarding the source and formation of the Fe-Si-Mn deposits in the VFR by showing that the samples of the HHF are a mixture of three components, namely, hydrothermal fluid, seawater and volcanic materials, whereas the samples of the MHF were dominated by hydrothermal fluids. The seawater had a minor influence on the Nd isotope data, and the Pb isotope data exhibited a close association with the substrate rock and preformed volcaniclastic layers in this area. The occurrence of relatively high Mn/Fe ratios in the hydrothermal deposits of this area may be a good indicator of the propagating activities of the VFR over geological time.

Regional framework and geology of iron oxide-apatite-rare earth element and iron oxide-copper-gold deposits of the Mesoproterozoic St. Francois Mountains Terrane, southeast Missouri

Science.gov (United States)

Day, Warren C.; Slack, John F.; Ayuso, Robert A.; Seeger, Cheryl M.

2016-01-01

This paper provides an overview on the genesis of Mesoproterozoic igneous rocks and associated iron oxide ± apatite (IOA) ± rare earth element, iron oxide-copper-gold (IOCG), and iron-rich sedimentary deposits in the St. Francois Mountains terrane of southeast Missouri, USA. The St. Francois Mountains terrane lies along the southeastern margin of Laurentia as part of the eastern granite-rhyolite province. The province formed during two major pulses of igneous activity: (1) an older early Mesoproterozoic (ca. 1.50–1.44 Ga) episode of volcanism and granite plutonism, and (2) a younger middle Mesoproterozoic (ca. 1.33–1.30 Ga) episode of bimodal gabbro and granite plutonism. The volcanic rocks are predominantly high-silica rhyolite pyroclastic flows, volcanogenic breccias, and associated volcanogenic sediments with lesser amounts of basaltic to andesitic volcanic and associated subvolcanic intrusive rocks. The iron oxide deposits are all hosted in the early Mesoproterozoic volcanic and volcaniclastic sequences. Previous studies have characterized the St. Francois Mountains terrane as a classic, A-type within-plate granitic terrane. However, our new whole-rock geochemical data indicate that the felsic volcanic rocks are effusive derivatives from multicomponent source types, having compositional similarities to A-type within-plate granites as well as to S- and I-type granites generated in an arc setting. In addition, the volcanic-hosted IOA and IOCG deposits occur within bimodal volcanic sequences, some of which have volcanic arc geochemical affinities, suggesting an extensional tectonic setting during volcanism prior to emplacement of the ore-forming systems.The Missouri iron orebodies are magmatic-related hydrothermal deposits that, when considered in aggregate, display a vertical zonation from high-temperature, magmatic ± hydrothermal IOA deposits emplaced at moderate depths (~1–2 km), to magnetite-dominant IOA veins and IOCG deposits emplaced at shallow

Lower and Middle Ordovician conodonts of Laurentian affinity from blocks of limestone in the Rosroe Formation, South Mayo Trough, western Ireland and their palaeogeographic implication

DEFF Research Database (Denmark)

Stouge, Svend; Harper, David A. T.; Sevastopulo, George D.

2016-01-01

The Middle Ordovician Rosroe Formation consists of some 1350m of coarse, mainly siliciclastic to volcaniclastic sedimentary rocks, deposited in a submarine fan environment, and is restricted to the southern limb of the South Mayo Trough, western Ireland. Discrete allochthonous blocks, reaching 5m...

Deposition and Characterization of TRISO Coating Layers

International Nuclear Information System (INIS)

Kim, Do Kyung; Kim, Min Woo; Lee, Hyeon Keun; Choi, Doo Jin; Kim, Jun Kyu; Cho, Sung Hyuk

2008-03-01

Both ZrC and SiC layers are crucial layers in TRISO coated fuel particles since they prevent diffusion of fission products and provide mechanical strength for the fuel particle. However, each layer has its own defects, so the purpose of this study is to complement such defects of these layers. In this study, we carried out thermodynamic simulations before actual experiments. With these simulation results, we deposited the ZrC layers on SiC/graphite substrates through CVD process. SiC films on graphite have different microstructures which are a hemispherical angular, domed top and faceted structure at different deposition temperature, respectively. According to the microstructures of SiC, preferred orientation, hardness and elastic modules of deposited ZrC layer were changed. TRISO particles. The fracture the SiC coating layer occurred by the tensile stress due to the traditional pressure vessel failure criteria. It is important to find fracture stress of SiC coating layer by the internal pressurization test method. The finite-element analysis was carried out to obtain the empirical equation of strength evaluation. By using this empirical equation, the mechanical properties of several types of SiC coating film with different microstructure and thicknesses will discussed

Deposition and Characterization of TRISO Coating Layers

Energy Technology Data Exchange (ETDEWEB)

Kim, Do Kyung; Kim, Min Woo; Lee, Hyeon Keun [KAIST, Daejeon (Korea, Republic of); Choi, Doo Jin; Kim, Jun Kyu; Cho, Sung Hyuk [Younsei University, Seoul (Korea, Republic of)

2008-03-15

Both ZrC and SiC layers are crucial layers in TRISO coated fuel particles since they prevent diffusion of fission products and provide mechanical strength for the fuel particle. However, each layer has its own defects, so the purpose of this study is to complement such defects of these layers. In this study, we carried out thermodynamic simulations before actual experiments. With these simulation results, we deposited the ZrC layers on SiC/graphite substrates through CVD process. SiC films on graphite have different microstructures which are a hemispherical angular, domed top and faceted structure at different deposition temperature, respectively. According to the microstructures of SiC, preferred orientation, hardness and elastic modules of deposited ZrC layer were changed. TRISO particles. The fracture the SiC coating layer occurred by the tensile stress due to the traditional pressure vessel failure criteria. It is important to find fracture stress of SiC coating layer by the internal pressurization test method. The finite-element analysis was carried out to obtain the empirical equation of strength evaluation. By using this empirical equation, the mechanical properties of several types of SiC coating film with different microstructure and thicknesses will discussed.

Geological factors of deposit formation

International Nuclear Information System (INIS)

Grushevoj, G.V.

1980-01-01

Geologic factors of hydrogenic uranium deposit formation are considered. Structural, formation and lithological-facies factors of deposit formation, connected with zones of stratal oxidation, are characterized. Peculiarities of deposit localization, connected with orogenic structures of Mesozoic and lenozoic age, are described. It is noted that deposits of anagenous group are widely spread in Paleozoic formations, infiltration uranium deposits are localized mainly in Cenozoic sediments, while uranium mineralization both anagenous and infiltration groups are widely developed in Mesozoic sediments. Anagenous deposits were formed in non-oxygen situation, their age varies from 200 to 55 mln years. Infiltration deposit formation is determined by asymmetric oxidation zonation, their age varies from 10 - 40 mln years to dozens of thousand years [ru

Room temperature synthesis and characterization of CdO nanowires by chemical bath deposition (CBD) method

International Nuclear Information System (INIS)

Dhawale, D.S.; More, A.M.; Latthe, S.S.; Rajpure, K.Y.; Lokhande, C.D.

2008-01-01

A chemical synthesis process for the fabrication of CdO nanowires is described. In the present work, transparent and conductive CdO films were synthesized on the glass substrate using chemical bath deposition (CBD) at room temperature. These films were annealed in air at 623 K and characterized for the structural, morphological, optical and electrical properties were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), optical and electrical resistivity. The XRD analysis showed that the as-deposited amorphous can be converted in to polycrystalline after annealing. Annealed CdO nanowires are 60-65 nm in diameter and length ranges typically from 2.5 to 3 μm. The optical properties revealed the presence of direct and indirect band gaps with energies 2.42 and 2.04 eV, respectively. Electrical resistivity measurement showed semiconducting behavior and thermoemf measurement showed n-type electrical conductivity

Structural characterization of AlN films synthesized by pulsed laser deposition

International Nuclear Information System (INIS)

Szekeres, A.; Fogarassy, Zs.; Petrik, P.; Vlaikova, E.; Cziraki, A.; Socol, G.; Ristoscu, C.; Grigorescu, S.; Mihailescu, I.N.

2011-01-01

We obtained AlN thin films by pulsed laser deposition (PLD) from a polycrystalline AlN target using a pulsed KrF* excimer laser source (248 nm, 25 ns, intensity of ∼4 x 10 8 W/cm 2 , repetition rate 3 Hz, 10 J/cm 2 laser fluence). The target-Si substrate distance was 5 cm. Films were grown either in vacuum (10 -4 Pa residual pressure) or in nitrogen at a dynamic pressure of 0.1 and 10 Pa, using a total of 20,000 subsequent pulses. The films structure was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and spectral ellipsometry (SE). Our TEM and XRD studies showed a strong dependence of the film structure on the nitrogen content in the ambient gas. The films deposited in vacuum exhibited a high quality polycrystalline structure with a hexagonal phase. The crystallite growth proceeds along the c-axis, perpendicular to the substrate surface, resulting in a columnar and strongly textured structure. The films grown at low nitrogen pressure (0.1 Pa) were amorphous as seen by TEM and XRD, but SE data analysis revealed ∼1.7 vol.% crystallites embedded in the amorphous AlN matrix. Increasing the nitrogen pressure to 10 Pa promotes the formation of cubic (≤10 nm) crystallites as seen by TEM but their density was still low to be detected by XRD. SE data analysis confirmed the results obtained from the TEM and XRD observations.

Chemical bath deposition of Hg doped CdSe thin films and their characterization

International Nuclear Information System (INIS)

Bhuse, V.M.

2005-01-01

The deliberate addition of Hg in CdSe thin film have been carried out using a simple, modified, chemical bath deposition technique with the objective to study the effect of Hg doping on properties of CdSe thin films. Synthesis was initiated at 278 K temperature using complexed cadmium sulphate, mercuric nitrate and sodium selenosulphate in an aqueous ammonical medium at pH 10. Films were characterized by XRD, SEM, optical absorption, electrical and thermoelectric techniques. The 'as deposited' films were uniform, well adherent, nearly stoichiometric and polycrystalline in a single cubic phase (zinc blende). Crystallite size determined from XRD and SEM was found to increase slightly with addition of Hg. The optical band gap of CdSe remains constant upto 0.05 mol% Hg doping, while it decreases monotonically with further increase in mercury content. Dark dc electrical resistivity and conduction activation energy of CdSe were found to decrease initially upto 0.05 mol% of Hg, thereafter increased for higher values of Hg but remains less than those of CdSe. All the films showed n-type of conductivity. A CdSe film containing 0.05 mol% of Hg showed higher absorption coefficient, and conductivity

Characterization of Wet and Dry Deposition in the Downwind of Industrial Sources in a Dry Tropical Area

Directory of Open Access Journals (Sweden)

Raj K. Singh

2001-01-01

Full Text Available An atmospheric deposition study was conducted in the downwind of Shaktinagar Thermal Power Plant (STPP, Renusagar Thermal Power Plant (RTPP, and Anpara Thermal Power Plant (ATPP, at Singrauli region, Uttar Pradesh (UP, India to characterize dry and wet deposition in relation to different pollution loading. During the study period, dry and wet depositions and levels of gaseous pollutants (SO2 and NO2 were estimated across the sites. Dry deposition was collected on a monthly basis and wet deposition on an event basis. Depositions were analyzed for pH, nitrate (NO3�, ammonium (NH4+, and sulphate (SO42� contents. Dry deposition rate both collected as clearfall and throughfall varied between 0.15 to 2.28 and 0.33 to 3.48 g m�2 day�1, respectively, at control and maximally polluted sites. The pH of dry deposition varied from 5.81 to 6.89 during winter and 6.09 to 7.02 during summer across the sites. During the rainy season, the mean pH of clear wet deposition varied from 6.56 to 7.04 and throughfall varied from 6.81 to 7.22. The concentrations of NO2 and SO2 pollutants were highest during the winter season. Mean SO2 concentrations varied from 18 to 75 �g m�3 at control and differently polluted sites during the winter season. The variation in NO2 concentrations did not show a pattern similar to that of SO2. The highest NO2 concentration during the winter season was 50 �g m�3, observed near RTPP. NO2 concentration did not show much variation among different sites, suggesting that the sources of NO2 emission are evenly distributed along the sites. The concentrations of NH4+, NO3�, and SO42� ions in dry deposition were found to be higher in summer as compared to the winter season. In dry deposition (clearfall the concentrations of NH4+, NO3�, and SO42� varied from 0.13 to 1.0, 0.81 to 1.95, and 0.82 to 3.27 mg l�1, respectively, during winter. In wet deposition (clearfall, the above varied from 0.14 to 0.74, 0.81 to 1.82, and 0

Characterization of wet and dry deposition in the downwind of industrial sources in a dry tropical area.

Science.gov (United States)

Singh, R K; Agrawal, M

2001-12-19

An atmospheric deposition study was conducted in the downwind of Shaktinagar Thermal Power Plant (STPP), Renusagar Thermal Power Plant (RTPP), and Anpara Thermal Power Plant (ATPP), at Singrauli region, Uttar Pradesh (UP), India to characterize dry and wet deposition in relation to different pollution loading. During the study period, dry and wet depositions and levels of gaseous pollutants (SO2 and NO2) were estimated across the sites. Dry deposition was collected on a monthly basis and wet deposition on an event basis. Depositions were analyzed for pH, nitrate (NO3-), ammonium (NH4+), and sulphate (SO4(2-)) contents. Dry deposition rate both collected as clearfall and throughfall varied between 0.15 to 2.28 and 0.33 to 3.48 g m(-2) day(-1), respectively, at control and maximally polluted sites. The pH of dry deposition varied from 5.81 to 6.89 during winter and 6.09 to 7.02 during summer across the sites. During the rainy season, the mean pH of clear wet deposition varied from 6.56 to 7.04 and throughfall varied from 6.81 to 7.22. The concentrations of NO2 and SO2 pollutants were highest during the winter season. Mean SO2 concentrations varied from 18 to 75 g m(-3) at control and differently polluted sites during the winter season. The variation in NO2 concentrations did not show a pattern similar to that of SO2. The highest NO2 concentration during the winter season was 50 g m(-3), observed near RTPP. NO2 concentration did not show much variation among different sites, suggesting that the sources of NO2 emission are evenly distributed along the sites. The concentrations of NH4+, NO3-, and SO4(2-) ions in dry deposition were found to be higher in summer as compared to the winter season. In dry deposition (clearfall) the concentrations of NH4+, NO3-, and SO4(2-) varied from 0.13 to 1.0, 0.81 to 1.95, and 0.82 to 3.27 mg l(-1), respectively, during winter. In wet deposition (clearfall), the above varied from 0.14 to 0.74, 0.81 to 1.82, and 0.67 to 2.70 mg l(-1

Geometrical Characterization of Sediment Deposits at the Confluence of Mountain Streams

Directory of Open Access Journals (Sweden)

Laura Maria Stancanelli

2018-03-01

Full Text Available Debris flow injections from tributaries into a main mountain stream generate deposits of sediments which, in turn, result in obstruction and eventual damming of the river section. This contribution presents the results of a series of flume experiments on the dynamics of these deposits, with reference to three different types of blockage: no blockage, partial blockage, and full blockage. Results show that the shape of the deposit is mainly controlled by the ratio between the debris flow discharge and the main river discharge. The experimental dataset is used to develop a deposit resilience stability index based on the shape of the deposit contour retrieved from photos taken from above. The proposed index is based on the invariant elliptic Fourier coefficients and the dimensionless transverse obstruction parameter. The elliptic Fourier coefficients give information on the symmetry of the deposit contour. High symmetry indicates more stable and resilient deposits. The proposed index is calibrated on the basis of the flume experiments and tested with field data. The results are quite promising and suggest that the index can be appropriate for a fast hazard assessment of multiple debris flow deposits at a regional scale.

Deposition and characterization of CuInSe2 films for solar cells using an optimized chemical route

International Nuclear Information System (INIS)

Berruet, M.; Schreiner, W.H.; Cere, S.; Vazquez, M.

2011-01-01

Research highlights: → CuInSe 2 has been deposited on glass by optimizing some parameters in the SILAR method. → Renewing the precursors after 40 cycles improves the composition of the deposit. → Photoelectrochemical tests and Mott-Schottky analysis confirm p-type conduction. → The quality of the material shows potential for application in solar cell devices. - Abstract: CuInSe 2 (CISe) thin films have been deposited on glass using successive ionic layer adsorption and reaction (SILAR). The as-deposited films are treated at 400 deg. C in argon atmosphere and etched in KCN solution to remove detrimental secondary phases. The preparation and temperature of the precursor solutions, the duration of the reaction cycles and the duration of the annealing stage have been optimized. The films have been characterized employing grazing incident X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive scanning spectroscopy. Relevant semiconductor parameters have been calculated. Photoelectrochemical tests confirm p-type conduction. The films are crystalline and the stoichiometry can be improved by renewing the precursor solution after completing half of the cycles, annealing for 90 min and later etching in KCN. The quality of the material seems to be promising for application in solar cell devices.

Deposition and Characterization of CVD-Grown Ge-Sb Thin Film Device for Phase-Change Memory Application

Directory of Open Access Journals (Sweden)

C. C. Huang

2012-01-01

Full Text Available Germanium antimony (Ge-Sb thin films with tuneable compositions have been fabricated on SiO2/Si, borosilicate glass, and quartz glass substrates by chemical vapour deposition (CVD. Deposition takes place at atmospheric pressure using metal chloride precursors at reaction temperatures between 750 and 875°C. The compositions and structures of these thin films have been characterized by micro-Raman, scanning electron microscope (SEM with energy dispersive X-ray analysis (EDX and X-ray diffraction (XRD techniques. A prototype Ge-Sb thin film phase-change memory device has been fabricated and reversible threshold and phase-change switching demonstrated electrically, with a threshold voltage of 2.2–2.5 V. These CVD-grown Ge-Sb films show promise for applications such as phase-change memory and optical, electronic, and plasmonic switching.

Palynological characterization of Givetian-Frasnian deposits in the reference Borehole section 1-Balneologicheskaya (Southern Timan)

Science.gov (United States)

Tel'Nova, O. P.

2008-04-01

A succession of seven palynological assemblages characterizing the Yuzhnyi Timan, Taman, Ust-Yarega, Domanik, and Vetlosyan formations of the southern Timan is established in the Givetian-Frasnian deposits recovered by Borehole 1-Balneologicheskaya and studied in detail. Five individual zones, which are distinguished within stratigraphic range of the optivus-krestovnicovii miospore zone, can be of basic importance for a high-resolution stratigraphic subdivision of the sedimentation stage under consideration. Phytostratigraphic boundary corresponding to the Frasnian Stage base in the East European platform is substantiated in palynological aspect.

Optical properties and surface characterization of pulsed laser-deposited Cu2ZnSnS4 by spectroscopic ellipsometry

International Nuclear Information System (INIS)

Crovetto, Andrea; Cazzaniga, Andrea; Ettlinger, Rebecca B.; Schou, Jørgen; Hansen, Ole

2015-01-01

Cu 2 ZnSnS 4 films prepared by pulsed laser deposition at different temperatures are characterized by spectroscopic ellipsometry. The focus is on confirming results from direct measurement techniques, by finding appropriate models of the surface overlayer for data fitting, and extracting the dielectric function of the films. It is found that the surface overlayer changes with film thickness and deposition temperature. Adopting different ellipsometry measurements and modeling strategies for each film, dielectric functions are extracted and compared. As the deposition temperature is increased, the dielectric functions exhibit additional critical points related to optical transitions in the material other than absorption across the fundamental band gap. In the case of a thin film < 200 nm thick, surface features observed by scanning electron microscopy and atomic force microscopy are accurately reproduced by ellipsometry data fitting. - Highlights: • Inhomogeneous Cu 2 ZnSnS 4 films are prepared by pulsed laser deposition. • The film surface includes secondary phases and topographic structures. • We model a film surface layer that fits ellipsometry data. • Ellipsometry data fits confirm results from direct measurement techniques. • We obtain the dielectric function of inhomogeneous Cu 2 ZnSnS 4 films

Characterization and in vitro biocompatibility study of Ti–Si–N nanocomposite coatings developed by using physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Trivedi, Pramanshu; Gupta, Pallavi [Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 India (India); Srivastava, Swati [Department of Biotechnology, Indian Institute of Technology Roorkee (India); Jayaganthan, R., E-mail: rjayafmt@iitr.ernet.in [Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 India (India); Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee (India); Chandra, Ramesh [Nanoscience Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee (India); Roy, Partha [Department of Biotechnology, Indian Institute of Technology Roorkee (India)

2014-02-28

Amongst the Ti alloys used as orthopedic implant materials, Ti6Al4V is one of the widely used alloys. Magnetron sputtering was used to deposit nanocomposite coating of Ti–Si–N on the Ti6Al4V substrate at different power and then the coating structure and surface properties were characterized through contact angle measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). In vitro biocompatibility of the coatings was assessed by using mouse bone marrow mesenchymal stem cells (mBMMSC). Antibacterial studies were performed using Escherichia coli (E. coli) microorganisms. The osteogenic differentiation was also carried out in order to get gene expressions. The AFM results confirmed that the coatings deposited at 120 W was smoother as compared to other coatings developed at different power, along with optimum contact angle, also these coatings showed good antibacterial results. The fluorescent and viability results of 120 W sample confirmed their good biocompatibility as compared to the coatings deposited 20, 40, 60, and 100 W power. Hence, the coating deposited at 120 W exhibit desirable microstructural characteristics beneficial for surface modification of orthopedic implants.

Characterization and in vitro biocompatibility study of Ti–Si–N nanocomposite coatings developed by using physical vapor deposition

International Nuclear Information System (INIS)

Trivedi, Pramanshu; Gupta, Pallavi; Srivastava, Swati; Jayaganthan, R.; Chandra, Ramesh; Roy, Partha

2014-01-01

Amongst the Ti alloys used as orthopedic implant materials, Ti6Al4V is one of the widely used alloys. Magnetron sputtering was used to deposit nanocomposite coating of Ti–Si–N on the Ti6Al4V substrate at different power and then the coating structure and surface properties were characterized through contact angle measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). In vitro biocompatibility of the coatings was assessed by using mouse bone marrow mesenchymal stem cells (mBMMSC). Antibacterial studies were performed using Escherichia coli (E. coli) microorganisms. The osteogenic differentiation was also carried out in order to get gene expressions. The AFM results confirmed that the coatings deposited at 120 W was smoother as compared to other coatings developed at different power, along with optimum contact angle, also these coatings showed good antibacterial results. The fluorescent and viability results of 120 W sample confirmed their good biocompatibility as compared to the coatings deposited 20, 40, 60, and 100 W power. Hence, the coating deposited at 120 W exhibit desirable microstructural characteristics beneficial for surface modification of orthopedic implants

Characterization and in vitro biocompatibility study of Ti-Si-N nanocomposite coatings developed by using physical vapor deposition

Science.gov (United States)

Trivedi, Pramanshu; gupta, Pallavi; Srivastava, Swati; Jayaganthan, R.; Chandra, Ramesh; Roy, Partha

2014-02-01

Amongst the Ti alloys used as orthopedic implant materials, Ti6Al4V is one of the widely used alloys. Magnetron sputtering was used to deposit nanocomposite coating of Ti-Si-N on the Ti6Al4V substrate at different power and then the coating structure and surface properties were characterized through contact angle measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). In vitro biocompatibility of the coatings was assessed by using mouse bone marrow mesenchymal stem cells (mBMMSC). Antibacterial studies were performed using Escherichia coli (E. coli) microorganisms. The osteogenic differentiation was also carried out in order to get gene expressions. The AFM results confirmed that the coatings deposited at 120 W was smoother as compared to other coatings developed at different power, along with optimum contact angle, also these coatings showed good antibacterial results. The fluorescent and viability results of 120 W sample confirmed their good biocompatibility as compared to the coatings deposited 20, 40, 60, and 100 W power. Hence, the coating deposited at 120 W exhibit desirable microstructural characteristics beneficial for surface modification of orthopedic implants.

Pulsed laser ablation and deposition of niobium carbide

International Nuclear Information System (INIS)

Sansone, M.; De Bonis, A.; Santagata, A.; Rau, J.V.; Galasso, A.; Teghil, R.

2016-01-01

Highlights: • We have deposited in vacuum niobium carbide films by fs and ns PLD. • We have compared PLD performed by ultra-short and short laser pulses. • The films deposited by fs PLD of NbC are formed by nanoparticles. • The structure of the films produced by fs PLD at 500 °C corresponds to NbC. - Abstract: NbC crystalline films have been deposited in vacuum by ultra-short pulsed laser deposition technique. The films have been characterized by transmission and scanning electron microscopies and by X-ray diffraction. To clarify the ablation–deposition mechanism, the plasma produced by the ablation process has been characterized by optical emission spectroscopy and fast imaging. A comparison of the results with those obtained by ns pulsed deposition of the same target has been carried out.

Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation; Sintesis y caracterizacion de peliculas delgadas de carbono amorfo nitrurado, depositadas por ablacion laser

Energy Technology Data Exchange (ETDEWEB)

Rebollo P, B

2001-07-01

The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp{sup 2} and sp{sup 3} bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

Spectral time-domain induced polarization and magnetic surveying – an efficient tool for characterization of solid waste deposits in developing countries

DEFF Research Database (Denmark)

Wemegah, David Dotse; Fiandaca, Gianluca; Auken, Esben

Time-domain induced polarization (IP) and magnetic data were acquired to map and characterize the decommissioned, un-engineered, municipal solid waste deposit site of the Kwame Nkrumah University of Science and Technology (KNUST), located in the Kumasi Metropolis of Ghana. Thirteen induced...... polarization profiles 500-800 m long and twenty-six magnetic profiles 600-800 m long were acquired, and two drillings were carried out in order to help in the interpretation of the geophysical data. The study was carried out with the aim of determining the risk posed by the waste deposit to the quality...... for interpreting the polarization data. The chargeability, resistivity, and the normalized chargeability distributions, together with the magnetic results, aided in a full characterization of the site geology, the waste and the associated pollution plume. In particular, clear contrasts in resistivity...

Ancillary effects of selected acid deposition control policies

Energy Technology Data Exchange (ETDEWEB)

Moe, R.J.; Lyke, A.J.; Nesse, R.J.

1986-08-01

NAPAP is examining a number of potential ways to reduce the precursors (sulfur dioxide and nitrogen oxides) to acid deposition. However, the policies to reduce acid deposition will have other physical, biological and economic effects unrelated to acid deposition. For example, control policies that reduce sulfur dioxide emissions may also increase visibility. The effects of an acid deposition policy that are unrelated to acid deposition are referred to as ''ancillary'' effects. This reserch identifies and characterizes the principle physical and economic ancillary effects associated with acid deposition control and mitigation policies. In this study the ancillary benefits associated with four specific acid deposition policy options were investigated. The four policy options investigated are: (1) flue gas desulfurization, (2) coal blending or switching, (3) reductions in automobile emissions of NO/sub x/, and (4) lake liming. Potential ancillary benefits of each option were identified and characterized. Particular attention was paid to the literature on economic valuation of potential ancillary effects.

Evaluation of the mineralogical characterization of several smectite clay deposits of the state of Paraiba, Brazil using statistical analysis of variance

International Nuclear Information System (INIS)

Gama, A.J.A.; Menezes, R.R.; Neves, G.A.; Brito, A.L.F. de

2015-01-01

Currently over 80% of industrialized bentonite clay produced in Brazil in sodium form for use in various industrial applications come from the deposits in Boa Vista - PB. Recently they were discovered new bentonite deposits situated in the municipalities of Cubati - PB, Drawn Stone - PB, Sossego - PB, and last in olive groves - PB, requiring systematic studies to develop all its industrial potential. Therefore, this study aimed to evaluate chemical characterization several deposits of smectite clays from various regions of the state of Paraíba through the analysis of statistical variance. Chemical analysis form determined by fluorescence x-ray (EDX). Then analyzes were carried out of variance statistics and Tukey test using the statistical soft MINITAB® 17.0. The results showed that the chemical composition of bentonite clay of new deposits showed different amounts of silica, aluminum, magnesium and calcium in relation clays in Boa Vista, and clays imported. (author)

Biomaterial thin film deposition and characterization by means of MAPLE technique

International Nuclear Information System (INIS)

Bloisi, F.; Vicari, L.; Papa, R.; Califano, V.; Pedrazzani, R.; Bontempi, E.; Depero, L.E.

2007-01-01

Polyethylene glycol (PEG) is a polymer with technologically important applications, especially as a biomaterial. Several biomedical applications (such as tissue engineering, spatial patterning of cells, anti-biofouling and biocompatible coatings) require the application of high quality PEG thin films. In order to have a good adhesion to substrate chemically modified polymer molecules have been used, but for some 'in vivo' applications it is essential to deposit a film with the same chemical and structural properties of bulk PEG. Pulsed laser deposition (PLD) technique is generally able to produce high quality thin films but it is inadequate for polymer/organic molecules. MAPLE (Matrix Assisted Pulsed Laser Evaporation) is a recently developed PLD based thin film deposition technique, particularly well suited for organic/polymer thin film deposition. Up to now MAPLE depositions have been carried out mainly by means of modified PLD systems, using excimer lasers operating in UV, but the use of less energetic radiations can minimize the photochemical decomposition of the polymer molecules. We have used a deposition system explicitly designed for MAPLE technique connected to a Q-switched Ng:YAG pulsed laser which can be operated at different wavelength ranging from IR to UV in order to optimise the deposition parameters. The capability of MAPLE technique to deposit PEG has been confirmed and preliminary results show that visible (532 nm wavelength) radiation gives better results with respect to UV (355 nm) radiation. Despite usually UV wavelengths have been used and even if more systematic tests must be performed, it is important to underline that the choice of laser wavelength plays an important role in the application of MAPLE thin film deposition technique

Fabrication and characterization of a cell electrostimulator device combining physical vapor deposition and laser ablation

Science.gov (United States)

Aragón, Angel L.; Pérez, Eliseo; Pazos, Antonio; Bao-Varela, Carmen; Nieto, Daniel

2017-08-01

In this work we present the process of fabrication and optimization of a prototype of a cell electrostimulator device for medical application combining physical vapor deposition and laser ablation. The fabrication of the first prototype begins with a deposition of a thin layer of 200 nm of aluminium on a borosilicate glass substrate using physical vapor deposition (PVD). In the second stage the geometry design of the electrostimulator is made in a CAD-like software available in a Nd:YVO4 Rofin Power line 20E, operating at the fundamental wavelength of 1064 nm and 20 ns pulse width. Choosing the proper laser parameters the negative of the electrostimulator desing is ablated. After that the glass is assembled between two polycarbonate sheets and a thick sheet of polydimethylsiloxane (PDMS). The PDMS sheet has a round hole in where cells are placed. There is also included a thin soda-lime silicate glass (100 μm) between the electrostimulator and the PMDS to prevent the cells for being in contact with the electric circuit. In order to control the electrical signal applied to the electrostimulator is used a digital I/O device from National Instruments (USB-6501) which provides 5 V at the output monitored by a software programmed in LabVIEW. Finally, the optical and electrical characterization of the cell electrostimulator device is presented.

Optical characterization of directly deposited graphene on a dielectric substrate

DEFF Research Database (Denmark)

Kaplas, Tommi; Karvonen, Lasse; Ahmadi, Sepehr

2016-01-01

By using scanning multiphoton microscopy we compare the nonlinear optical properties of the directly deposited and transferred to the dielectric substrate graphene. The direct deposition of graphene on oxidized silicon wafer was done by utilizing sacrificial copper catalyst film. We demonstrate...

Microstructural and mechanical characterization of laser deposited advanced materials

Science.gov (United States)

Sistla, Harihar Rakshit

Additive manufacturing in the form of laser deposition is a unique way to manufacture near net shape metallic components from advanced materials. Rapid solidification facilitates the extension of solid solubility, compositional flexibility and decrease in micro-segregation in the melt among other advantages. The current work investigates the employment of laser deposition to fabricate the following: 1. Functionally gradient materials: This allows grading dissimilar materials compositionally to tailor specific properties of both these materials into a single component. Specific compositions of the candidate materials (SS 316, Inconel 625 and Ti64) were blended and deposited to study the brittle intermetallics reported in these systems. 2. High entropy alloys: These are multi- component alloys with equiatomic compositions of 5 or more elements. The ratio of Al to Ni was decreased to observe the transition of solid solution from a BCC to an FCC crystal structure in the AlFeCoCrNi system. 3. Structurally amorphous alloys: Zr-based metallic glasses have been reported to have high glass forming ability. These alloys have been laser deposited so as to rapidly cool them from the melt into an amorphous state. Microstructural analysis and X-ray diffraction were used to study the phase formation, and hardness was measured to estimate the mechanical properties.

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

International Nuclear Information System (INIS)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-01-01

Graphical abstract: - Abstract: We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

Science.gov (United States)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-12-01

We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES.

Deposition and characterization of CuInSe{sub 2} films for solar cells using an optimized chemical route

Energy Technology Data Exchange (ETDEWEB)

Berruet, M. [Division Corrosion, INTEMA, CONICET, Facultad de Ingenieria, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Schreiner, W.H. [Laboratorio de Superficies e Interfases, Departamento de Fisica, Universidade Federal do Parana, 81531-990 Curitiba, PR (Brazil); Cere, S. [Division Corrosion, INTEMA, CONICET, Facultad de Ingenieria, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Vazquez, M., E-mail: mvazquez@fi.mdp.edu.ar [Division Corrosion, INTEMA, CONICET, Facultad de Ingenieria, Universidad Nacional de Mar del Plata, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina)

2011-02-10

Research highlights: > CuInSe{sub 2} has been deposited on glass by optimizing some parameters in the SILAR method. > Renewing the precursors after 40 cycles improves the composition of the deposit. > Photoelectrochemical tests and Mott-Schottky analysis confirm p-type conduction. > The quality of the material shows potential for application in solar cell devices. - Abstract: CuInSe{sub 2} (CISe) thin films have been deposited on glass using successive ionic layer adsorption and reaction (SILAR). The as-deposited films are treated at 400 deg. C in argon atmosphere and etched in KCN solution to remove detrimental secondary phases. The preparation and temperature of the precursor solutions, the duration of the reaction cycles and the duration of the annealing stage have been optimized. The films have been characterized employing grazing incident X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive scanning spectroscopy. Relevant semiconductor parameters have been calculated. Photoelectrochemical tests confirm p-type conduction. The films are crystalline and the stoichiometry can be improved by renewing the precursor solution after completing half of the cycles, annealing for 90 min and later etching in KCN. The quality of the material seems to be promising for application in solar cell devices.

Preparation and characterization of ALD deposited ZnO thin films studied for gas sensors

Energy Technology Data Exchange (ETDEWEB)

Boyadjiev, S.I., E-mail: boiajiev@gmail.com [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Georgieva, V. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Yordanov, R. [Department of Microelectronics, Technical University of Sofia, 8 Kliment Ohridski Blvd., 1756 Sofia (Bulgaria); Raicheva, Z. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Szilágyi, I.M. [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Budapest University of Technology and Economics, Department of Inorganic and Analytical Chemistry, Szent Gellért tér 4, Budapest, H-1111 (Hungary)

2016-11-30

Highlights: • For the first time the gas sensing towards NO{sub 2} of very thin ALD ZnO films is studied. • The very thin ALD ZnO films showed excellent sensitivity to NO{sub 2} at room temperature. • These very thin film ZnO-based QCM sensors very well register even low concentrations. • The sensors have fully reversible sorption and are able to be recovered in short time. • Described fast and cost-effective ALD deposition of ZnO thin films for QCM gas sensor. - Abstract: Applying atomic layer deposition (ALD), very thin zinc oxide (ZnO) films were deposited on quartz resonators, and their gas sensing properties were studied using the quartz crystal microbalance (QCM) method. The gas sensing of the ZnO films to NO{sub 2} was tested in the concentration interval between 10 and 5000 ppm. On the basis of registered frequency change of the QCM, for each concentration the sorbed mass was calculated. Further characterization of the films was carried out by various techniques, i.e. by SEM-EDS, XRD, ellipsometry, and FTIR spectroscopy. Although being very thin, the films were gas sensitive to NO{sub 2} already at room temperature and could register very well as low concentrations as 100 ppm, while the sorption was fully reversible. Our results for very thin ALD ZnO films show that the described fast, simple and cost-effective technology could be implemented for producing gas sensors working at room temperature and being capable to detect in real time low concentrations of NO{sub 2}.

Electrochemical and morphological characterization of gold nanoparticles deposited on boron-doped diamond electrode

Energy Technology Data Exchange (ETDEWEB)

Limat, Meriadec; El Roustom, Bahaa [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland); Jotterand, Henri [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Physics of the Complex Matter, CH-1015 Lausanne (Switzerland); Foti, Gyoergy [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland)], E-mail: gyorgy.foti@epfl.ch; Comninellis, Christos [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne (Switzerland)

2009-03-30

A novel two-step method was employed to synthesize gold nanoparticles dispersed on boron-doped diamond (BDD) electrode. It consisted of sputter deposition at ambient temperature of maximum 15 equivalent monolayers of gold, followed by a heat treatment in air at 600 deg. C. Gold nanoparticles with an average diameter between 7 and 30 nm could be prepared by this method on polycrystalline BDD film electrode. The obtained Au/BDD composite electrode appeared stable under conditions of electrochemical characterization performed using ferri-/ferrocyanide and benzoquinone/hydroquinone redox couples in acidic medium. The electrochemical behavior of Au/BDD was compared to that of bulk Au and BDD electrodes. Finally, the Au/BDD composite electrode was regarded as an array of Au microelectrodes dispersed on BDD substrate.

Electrochemical and morphological characterization of gold nanoparticles deposited on boron-doped diamond electrode

International Nuclear Information System (INIS)

Limat, Meriadec; El Roustom, Bahaa; Jotterand, Henri; Foti, Gyoergy; Comninellis, Christos

2009-01-01

A novel two-step method was employed to synthesize gold nanoparticles dispersed on boron-doped diamond (BDD) electrode. It consisted of sputter deposition at ambient temperature of maximum 15 equivalent monolayers of gold, followed by a heat treatment in air at 600 deg. C. Gold nanoparticles with an average diameter between 7 and 30 nm could be prepared by this method on polycrystalline BDD film electrode. The obtained Au/BDD composite electrode appeared stable under conditions of electrochemical characterization performed using ferri-/ferrocyanide and benzoquinone/hydroquinone redox couples in acidic medium. The electrochemical behavior of Au/BDD was compared to that of bulk Au and BDD electrodes. Finally, the Au/BDD composite electrode was regarded as an array of Au microelectrodes dispersed on BDD substrate

Preparation and characterization of Ge2Sb2Te5 phase change films on elastic substrates by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Lu, Hongbing; Thelander, Erik; Benke, Julia; Rauschenbach, Bernd [Leibniz Institute of Surface Modification, 04318 Leipzig (Germany)

2012-07-01

Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) thin films have attracted a great deal of interest as an active layer for data storage media due to its high switching rate and extremely good reversibility. Here we demonstrate the preparation of high-quality GST films on elastic polyimide substrates by pulsed laser deposition (PLD). The composition and chemical state of the films were investigated by energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS), respectively. The effect of annealing temperature on the crystalline nature of the films was also studied. As-deposited films were found to be amorphous. Crystalline phases with face-centered cubic and hexagonal structures appeared at 180 and 300 degrees, respectively. Importantly, no phase separation could be seen in the annealed films. Furthermore, reflectivity measurements were performed to characterize the as-deposited and annealed films, showing a high reflectivity contrast (up to 23%) between full crystalline and amorphous films. Our results indicate that PLD deposited GST film on polyimide substrate is a promising candidate for use in future flexible memory devices.

Morpho-Structural Characterization of WC20Co Deposited Layers

Science.gov (United States)

Tugui, C. A.; Vizureanu, P.

2017-06-01

Hydroelectric power plants use the power of water to produce electricity. In this paper we propose a solution that will increase the efficiency of turbine operation by implementing new innovative technologies to increase the working characteristics by depositing hard thin films of tungsten carbide. For this purpose hard tough deposits with WC20Co and Jet Plasma Jet on X3CrNiMo13-4 stainless steel were used for the realization of the Francis turbine with vertical shaft.

Characterization of 13 and 30 mum thick hydrogenated amorphous silicon diodes deposited over CMOS integrated circuits for particle detection application

CERN Document Server

Despeisse, M; Commichau, S C; Dissertori, G; Garrigos, A; Jarron, P; Miazza, C; Moraes, D; Shah, A; Wyrsch, N; Viertel, Gert M; 10.1016/j.nima.2003.11.022

2004-01-01

We present the experimental results obtained with a novel monolithic silicon pixel detector which consists in depositing a n-i-p hydrogenated amorphous silicon (a-Si:H) diode straight above the readout ASIC (this technology is called Thin Film on ASIC, TFA). The characterization has been performed on 13 and 30mum thick a-Si:H films deposited on top of an ASIC containing a linear array of high- speed low-noise transimpedance amplifiers designed in a 0.25mum CMOS technology. Experimental results presented have been obtained with a 600nm pulsed laser. The results of charge collection efficiency and charge collection speed of these structures are discussed.

Effects of deposition time in chemically deposited ZnS films in acidic solution

Energy Technology Data Exchange (ETDEWEB)

Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

2015-08-31

We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

Characterization of Dredged Oyster Shell Deposits at Mobile Bay, Alabama Using Geophysical Methods

Directory of Open Access Journals (Sweden)

Stanley C. Nwokebuihe

2016-12-01

Full Text Available The need for disposing materials dredged from ship channels is a common problem in bays and lagoons. This study is aimed at investigating the suitability of scour features produced by dredging oyster shell deposits in Mobile Bay, Alabama, to dispose excavated channel material. A study area approximately 740 by 280 m lying about 5 km east of Gaillard Island was surveyed using underwater electrical resistivity tomography (UWERT and continuous electrical resistivity profiling (CERP tools. The geophysical survey was conducted with the intent to map scour features created by oyster shell dredging activities in the bay between 1947 and 1982. The geoelectrical surveys show that oyster beds are characterized by high resistivity values greater than 1.1 ohm.m while infilled dredge cuts show lower resistivity, generally from 0.6 to 1.1 ohm.m. The difference in resistivity mainly reflects the lithology and the consolidation of the shallow sediments: consolidated silty clay and sandy sediments rich in oyster shell deposits (with less clay content overlying unconsolidated clayey materials infilling the scours. Results show that most of the infilled dredge cuts are mostly distributed in the north-south direction. Considering that the scours are generally up to 6 m deep across the survey location, it is estimated that about 0.8 million cubic meters of oyster shells and overlying strata were dredged from the survey location.

Improvements to the characterization of organic nitrogen chemistry and deposition in CMAQ

Science.gov (United States)

Excess atmospheric nitrogen deposition can cause significant harmful effects to ecosystems. Organic nitrogen deposition can be an important contributor to the total nitrogen budget, contributing 10-30%, however there are large uncertainties in the chemistry and deposition of thes...

Characterization of ultra-fast deposited polycrystalline graphite by a CO{sub 2} laser-assisted combustion-flame method

Energy Technology Data Exchange (ETDEWEB)

McKindra, Travis, E-mail: mckindra@mst.edu [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Patil, Sandeep; O' Keefe, Matthew J. [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Han Yaoxuan; Ling Hao; Lu Yongfeng [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States)

2009-02-15

High deposition rate, 750 {mu}m/min, crystalline graphite was deposited on WC substrates by a CO{sub 2} laser-assisted combustion-flame method at laser powers between 300 and 800 W. The structures, which were identified as pillars, were characterized by various methods. The pillars were cylindrical in shape and grew to a size of approximately 3 mm in length and in a few minutes. The laser power did not affect the overall length of the pillar, but caused changes in the physical shape. X-ray and electron diffraction results revealed the pillars to be crystalline graphite regardless of the laser power. Investigation of the pillars by scanning electron microscopy showed two distinct microstructural areas: an inner core of dense material surrounded by an outer shell of lamellar-like material. The core/shell microstructure was unaffected by the level of CO{sub 2} laser power.

Characterization of hydroxyapatite coating by pulse laser deposition technique on stainless steel 316 L by varying laser energy

International Nuclear Information System (INIS)

Khandelwal, Himanshu; Singh, Gurbhinder; Agrawal, Khelendra; Prakash, Satya; Agarwal, R.D.

2013-01-01

Highlights: ► Hydroxyapatite coating was successfully deposited on stainless steel substrate by pulse laser deposition at different energy levels (i.e. 300 mJ and 500 mJ, respectively). ► Variation in laser energy affects the surface characteristic of hydroxyapatite coating (particle size, surface roughness, uniformity, Ca/P ratio). ► Laser energy between 300 mJ and 500 mJ is the optimal choice for obtaining ideal Ca/P ratio. - Abstract: Hydroxyapatite is an attractive biomaterial mainly used in bone and tooth implants because it closely resembles human tooth and bone mineral and has proven to be biologically compatible with these tissues. In spite of this advantage of hydroxyapatite it has also certain limitation like inferior mechanical properties which do not make it suitable for long term load bearing applications; hence a lot of research is going on in the development of hydroxyapatite coating over various metallic implants. These metallic implants have good biocompatibility and mechanical properties. The aim of the present work is to deposit hydroxyapatite coating over stainless steel grade 316 L by pulse laser deposition technique by varying laser energy. To know the effect of this variation, the coatings were than characterized in detail by X-ray diffraction, finite emission-scanning electron microscope, atomic force microscope and energy dispersive X-ray spectroscopy.

The influences of target properties and deposition times on pulsed laser deposited hydroxyapatite films

International Nuclear Information System (INIS)

Bao Quanhe; Chen Chuanzhong; Wang Diangang; Liu Junming

2008-01-01

Hydroxyapatite films were produced by pulsed laser deposition from three kinds of hydroxyapatite targets and with different deposition times. A JXA-8800R electron probe microanalyzer (EPMA) with a Link ISIS300 energy spectrum analyzer was used to give the secondary electron image (SE) and determine the element composition of the films. The phases of thin film were analyzed by a D/max-γc X-ray diffractometer (XRD). The Fourier-transform infrared spectroscopy (FT-IR) was used to characterize the hydroxyl, phosphate and other functional groups. The results show that deposited films were amorphous which mainly composed of droplet-like particles and vibration of PO 4 3- groups. With the target sintering temperature deposition times increasing, the density of droplets is decreased. While with deposition times increasing, the density of droplets is increased. With the target sintering temperature and deposition time increasing, the ratio of Ca/P is increasing and higher than that of theoretical value of HA

Contrasting styles of deep-marine pyroclastic eruptions revealed from Axial Seamount push core records

Science.gov (United States)

Portner, Ryan A.; Clague, David A.; Helo, Christoph; Dreyer, Brian M.; Paduan, Jennifer B.

2015-08-01

A comprehensive understanding of explosive basaltic eruption processes in the deep-sea relies upon detailed analysis and comparison of the variety of volcaniclastic lithologies on the seafloor, which has been challenged by insufficient sample recovery. A dedicated ROV-based sampling approach using long push cores offers an unparalleled opportunity to fully characterize the diversity of unconsolidated volcaniclastic lithofacies on a recently active seamount. Lithofacies from Axial Seamount record two styles of pyroclastic eruptions, strombolian and phreatomagmatic, at 1.5 km water depth. Strombolian eruptions are represented by abundant fluidal and highly vesicular (up to 50%) vitriclasts within limu o Pele lapilli tuff and tuffaceous mud lithofacies. Lapilli-ash grain size, normal grading, good sorting, rip-up clasts and homogeneous glass geochemistry characterize individual limu o Pele lapilli tuff beds, and imply proximal deposition from a turbidity flow associated with a single eruption (i.e. event bed). Limu o Pele lapilli tuff beds are interbedded with poorly sorted, chemically heterogeneous and bioturbated tuffaceous mud units that preserve reworking and biologic habitation of more distal pyroclastic fallout and dilute turbidity flows. The phreatomagmatic eruption style is preserved by hydrothermal mineral-bearing muddy tuff that exhibits characteristics distinct from lapilli ash and tuffaceous mud lithofacies. Hydrothermal muddy tuff lithofacies are well-sorted and fine-grained with notable components of non-fluidal basaltic ash (∼45%), fluidal ash (∼30%) and accessory lithics (∼25%). Heterogeneous geochemistry of ash shards implies that juvenile components are minimal. The abundance, mineralogy and texture of lithic components (Fe-Mg clays, pyrite, epidote, actinolite, altered glass, basalt/diabase, hydrothermal breccia and agglutinate), and very fine-grain size of basaltic ash, are consistent with phreatomagmatic eruption deposits. A lack of

Evaluation of methods for characterizations of deposits; Utvaerdering av metoder foer avlagringsmaetningar

Energy Technology Data Exchange (ETDEWEB)

Hoegberg, J.; Bjoerkman, P. [Vattenfall Utveckling AB, Aelvkarleby (Sweden)

2001-11-01

In boilers there are problems with deposits on parts exposed to the flue gas, in particular on heat exchanging parts and to an increasing extent with the changeover to the use of biofuels and wood waste fuels. In order to solve the problems deposits are examined by using a deposit probe and taking deposit samples from the interior of the boiler. In this report an evaluation of methods of analysis is performed based on experiences in both literature and laboratory work. The evaluation forms the basis of an instruction for deposit measurements in 'Vaermeforsks Maethandbok'. The procedure for use of deposit probes is treated as well as the importance of careful and well planned sample preparation before analysis. In the literature a large number of methods used for analysis of deposits from flue ashes and similar applications are found. The methods include chemical analyses of solids and liquids, analysis of crystal structures, thermal properties and the solid mechanics of the materials. Several methods, for example SEM-EDX, XRF, ICP, IC and methods for determining the mechanical and thermal properties are suited for a survey examination of a deposit, while more specialised methods with higher resolution can add information but require a clear framing of a question and in practice are suited for only separate samples. Examples from the latter category are AES, ESCA and TOF-SIMS.

Polymer deposition morphology by electrospray deposition - Modifications through distance variation

International Nuclear Information System (INIS)

Altmann, K.; Schulze, R.-D.; Friedrich, J.

2014-01-01

Electrospray deposition (ESD) of highly diluted polymers was examined with regard to the deposited surface structure. Only the flight distance (flight time) onto the resulting deposited surface was varied from 20 to 200 mm. An apparatus without any additional heating or gas flows was used. Polyacrylic acid (PAA) and polyallylamine (PAAm) in methanol were deposited on Si wafers. The polymer layers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, derivatization reactions and Fourier transform infrared spectroscopy using a grazing incidence unit. SEM images illustrated the changing structures of PAA and PAAm. For PAA the deposited structure changed from a smooth film (20 mm) to a film with individual droplets on the coated surface (100 mm and 200 mm), while for PAAm individual droplets can be seen at all distances. The ESD process with cascades of splitting droplets slows down for PAA after distances greater than 40 mm. In contrast, the ESD process for PAAm is nearly stopped within the first flight distance of 20 mm. Residual solvent analysis showed that most of the solvent evaporated within the first 20 mm capillary-sample distance. - Highlights: • We deposited polyacrylic acid and polyallylamine by electrospray ionization (ESI). • The morphology in dependence of flight distance (20 mm to 200 mm) was analyzed. • The amount of residual solvent after deposition was determined. • ESI-process slows down for polyacrylic acid after 40 mm flight distance. • ESI-Process is complete for polyallylamine within the first 20 mm

Synthesis Characterization and Decomposition Studies of tris[N-N-dibenzyidithocarbaso)Indium (III) Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

Science.gov (United States)

Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.

2005-01-01

This paper presents the results of the synthesis characterization and decomposition studies of tris[N-N-dibenzyidithocarbaso)Indium (III) with chemical spray deposition of polycrystalline CuInS2 on Copper Films.

Cu-Ag Besshi type volcanogenic massive sulfide mineralization in the Late Cretaceous volcano- sedimentary sequence: the case of Garmabe Paein deposit, southeast of Shahrood

Directory of Open Access Journals (Sweden)

Majid Tashi

2017-07-01

Full Text Available Introduction Iran hosts numerous types of Volcanogenic massive sulfide (VMS deposits that occur within different tectonic assemblages and have formed at discrete time periods (Mousivand et al. 2008. The Sabzevar zone hosts several VMS deposits including the Nudeh Cu-Ag deposit (Maghfouri, 2012 and some deposits in the Kharturan area (Tashi et al., 2014, and the Kharturan area locates in the Sabzevar subzone of the Central East Iranian Microcontinent. The Sabzevar subzone mainly involves Mesozoic and Cenozoic rock unites. The Late Cretaceous ophiolite mellanges and volcano-sedimentary sequences have high extension in the Subzone. Based on Rossetti (Rossetti et al. 2010, the Cretaceous rock units were formed in a back-arc setting due to subduction of the Neo-Tethyan oceanic crust beneath the Iranian plate. The exposed rock units of the Kharturan area from bottom to top are dominated by Early Cretaceous, orbitolina-bearing massive limestone, dacitic-andesitic volcanics and related volcaniclastic rocks٫ chert and radiolarite and Late Cretaceous globotrunkana- bearing limestone, paleocene polygenic conglomerate consisting of the Cretaceous volcanics and limestone pebbles (equal to the Kerman conglomerate, and Pliocene weakly-cemented polygenic conglomerate horizon. The Garmabe Paein copper-silver deposit and the Asbkeshan deposit and a few occurrences, are located at 290 km southeast of Shahrood and they have occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone. The aim of this study is to discuss the genesis of the Garmabe Paein deposit based on geological, textural and structural, mineralogical and geochemical evidence. Materials and methods A field study and sampling was performed during the year 2013. During the field observations, 94 rock samples were collected from the study area, and 45 thin sections were prepared and studied using a polarizing microscope. Also, 5 samples for the XRD method, 21 samples for

Electrostatic Deposition of Large-Surface Graphene

Directory of Open Access Journals (Sweden)

Charles Trudeau

2018-01-01

Full Text Available This work describes a method for electrostatic deposition of graphene over a large area using controlled electrostatic exfoliation from a Highly Ordered Pyrolytic Graphite (HOPG block. Deposition over 130 × 130 µm2 with 96% coverage is achieved, which contrasts with sporadic micro-scale depositions of graphene with little control from previous works on electrostatic deposition. The deposition results are studied by Raman micro-spectroscopy and hyperspectral analysis using large fields of view to allow for the characterization of the whole deposition area. Results confirm that laser pre-patterning of the HOPG block prior to cleaving generates anchor points favoring a more homogeneous and defect-free HOPG surface, yielding larger and more uniform graphene depositions. We also demonstrate that a second patterning of the HOPG block just before exfoliation can yield features with precisely controlled geometries.

Deposition and characterization of plasma sprayed Ni-5A1/ magnesia stabilized zirconia based functionally graded thermal barrier coating

International Nuclear Information System (INIS)

Baig, M N; Khalid, F A

2014-01-01

Thermal barrier coatings (TBCs) are employed to protect hot section components in industrial and aerospace gas turbine engines. Conventional TBCs frequently fail due to high residual stresses and difference between coefficient of thermal expansion (CTE) of the substrate and coatings. Functionally graded thermal barrier coatings (FG-TBCs) with gradual variation in composition have been proposed to minimize the problem. In this work, a five layered functionally graded thermal barrier coating system was deposited by atmospheric plasma spray (APS) technique on Nimonic 90 substrates using Ni-5Al as bond coat (BC) and magnesia stabilized zirconia as top coat (TC). The coatings were characterized by SEM, EDS, XRD and optical profilometer. Microhardness and coefficient of thermal expansion of the five layers deposited as individual coatings were also measured. The deposited coating system was oxidized at 800°C. SEM analysis showed that five layers were successfully deposited by APS to produce a FG-TBC. The results also showed that roughness (Ra) of the individual layers decreased with an increase in TC content in the coatings. It was found that microhardness and CTE values gradually changed from bond coat to cermet layers to top coat. The oxidized coated sample revealed parabolic behavior and changes in the surface morphology and composition of coating

Electrical characterization of defects introduced in n-Si during electron beam deposition of Pt

Energy Technology Data Exchange (ETDEWEB)

Auret, F.D.; Coelho, S.M.M.; Nel, J.M.; Meyer, W.E. [Physics Department, University of Pretoria, Pretoria (South Africa)

2012-10-15

We have used deep level transient spectroscopy (DLTS) and high resolution DLTS to characterize the defects introduced in epitaxially grown n-type, P-doped, Si during electron beam deposition (EBD) of Pt for Schottky contact formation. The identity of some of these defects could be established by comparing their properties to those of well-known defects introduced by high energy electron irradiation of the same material. The most prominent EBD-induced defects thus identified were the E-center (VP center), the A-center (VO center), interstitial carbon (C{sub i}), and the interstitial carbon-substitutional carbon (C{sub i}C{sub s}) pair. EBD also introduced some defects that were not observed after high energy electron irradiation. DLTS depth profiling revealed that the main defects, VO and VP, could be detected up to 0.5 {mu}m below the metal-Si interface. Shielding the sample from particles originating in the region of the electron beam significantly reduced defect introduction and resulted in Schottky contacts with improved rectification properties. Finally, we have found that exposing the sample to EBD conditions, without actually depositing metal, introduced a different set of electron traps, not introduced by the EBD process. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Electroless deposition, post annealing and characterization of nickel ...

Indian Academy of Sciences (India)

Wintec

Currently at: Department of Physics, Columbia University, New York, USA. MS received 9 ... The electroless deposition is a promising method to prepare durable metal films on both .... graphic data available in literature. The XRD patterns were ...

Characterization of the yttria-stabilized zirconia thin film electrophoretic deposited on La0.8Sr0.2MnO3 substrate

International Nuclear Information System (INIS)

Yang, Koho; Shen, Jung-Hsiung; Yang, Kai-Yun; Hung, I-Ming; Fung, Kuan-Zong; Wang, Moo-Chin

2007-01-01

The yttria-stabilized zirconia (YSZ) thin films electrophoretic deposited on the La 0.8 Sr 0.2 MnO 3 (LSM) substrate have been characterized by using zeta potential analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The La 2 Zr 2 O 7 (LZ) formed at the interface between the YSZ thin film and LSM substrate, after sintered at 1400 o C for 52 h, are identified by XRD. The zeta potential of the YSZ particles in pure ethanol-acetone is about 7.8 mV, but when the I 2 concentration is greater than 0.6 g/1, the zeta potential attains a constant value, 46 mV. The relation between deposit weight of the YSZ films and the applied voltage shows a non-linear behavior. Thickness of the YSZ thin film deposited on the LSM substrate by electrophoretic deposition is controlled by a diffusion process. A larger LZ with the thickness of 200 nm is formed at the interface between the YSZ film and the LSM substrate

Characterization of previously unidentified lunar pyroclastic deposits using Lunar Reconnaissance Orbiter Camera (LROC) data

Science.gov (United States)

Gustafson, J. Olaf; Bell, James F.; Gaddis, Lisa R.R.; Hawke, B. Ray Ray; Giguere, Thomas A.

2012-01-01

We used a Lunar Reconnaissance Orbiter Camera (LROC) global monochrome Wide-angle Camera (WAC) mosaic to conduct a survey of the Moon to search for previously unidentified pyroclastic deposits. Promising locations were examined in detail using LROC multispectral WAC mosaics, high-resolution LROC Narrow Angle Camera (NAC) images, and Clementine multispectral (ultraviolet-visible or UVVIS) data. Out of 47 potential deposits chosen for closer examination, 12 were selected as probable newly identified pyroclastic deposits. Potential pyroclastic deposits were generally found in settings similar to previously identified deposits, including areas within or near mare deposits adjacent to highlands, within floor-fractured craters, and along fissures in mare deposits. However, a significant new finding is the discovery of localized pyroclastic deposits within floor-fractured craters Anderson E and F on the lunar farside, isolated from other known similar deposits. Our search confirms that most major regional and localized low-albedo pyroclastic deposits have been identified on the Moon down to ~100 m/pix resolution, and that additional newly identified deposits are likely to be either isolated small deposits or additional portions of discontinuous, patchy deposits.

Characterization and Quantification of Deposits Buildup and Removal in Biomass Suspension-Fired Boilers

DEFF Research Database (Denmark)

Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming

2010-01-01

Utilization of biomass as wood or straw in large suspension­fired boilers is an efficient method to reduce the use of fossil fuels consumption and to reduce the net CO2 formation. However, the presence of chlorine and alkali metals in biomass (straw) generate ash with a low melting point and induce...... large problems of ash deposit formation on the superheater tubes. Full scale studies on biomass ash deposition and removal had been done on biomass grate boilers, while only limited data is available from biomass suspension­firing. The aim of this study was to investigate deposit mass uptake, heat...... uptake reduction, fly ash and deposit characteristics, and deposit removal by using an advanced online deposit probe in a suspension­fired boiler using wood and straw pellets as fuel. The influence of fuel type and probe exposure time on the ash deposition rate, the heat uptake, the fly ash and deposit...

Deposition and characterization of ZnO thin films by modified pulsed-spray pyrolysis

International Nuclear Information System (INIS)

Thilakan, Periyasamy; Radheep, D Mohan; Saravanakumar, K; Sasikala, G

2009-01-01

Zinc oxide (ZnO) thin films were deposited using modified pulsed-spray pyrolysis on glass substrates. Depositions were carried out using N 2 as the carrier gas and analysed with respect to the rate of deposition. X-ray analysis revealed the presence of mixed crystallization with a nanocrystalline structure of about 6.9 nm dispersed in the amorphous matrix. A negative trend between the bandgap and resistivity was observed with the decrease in the deposition rate. A lowest bandgap of 3.1 eV with a resistivity value of 1.6 × 10 −2 Ω cm was achieved at a lowest deposition rate of 1.3 nm min −1 . Hot-probe measurement revealed the p-type conductivity for the film deposited at a lowest deposition rate of 1.3 nm min −1 . Details about the influence of pulsed-spray deposition for the achievement of this negative trend between bandgap and resistivity will be discussed in this paper

Structural characterization of ultrathin Cr-doped ITO layers deposited by double-target pulsed laser ablation

International Nuclear Information System (INIS)

Cesaria, Maura; Caricato, Anna Paola; Leggieri, Gilberto; Luches, Armando; Martino, Maurizio; Maruccio, Giuseppe; Catalano, Massimo; Manera, Maria Grazia; Rella, Roberto; Taurino, Antonietta

2011-01-01

In this paper we report on the growth and structural characterization of very thin (20 nm) Cr-doped ITO films, deposited at room temperature by double-target pulsed laser ablation on amorphous silica substrates. The role of Cr atoms in the ITO matrix is carefully investigated with increasing doping content by transmission electron microscopy (TEM). Selected-area electron diffraction, conventional bright field and dark field as well as high-resolution TEM analyses, and energy dispersive x-ray spectroscopy demonstrate that (i) crystallization features occur despite the low growth temperature and small thickness, (ii) no chromium or chromium oxide secondary phases are detectable, regardless of the film doping levels, (iii) the films crystallize as crystalline flakes forming large-angle grain boundaries; (iv) the observed flakes consist of crystalline planes with local bending of the crystal lattice. Thickness and compositional information about the films are obtained by Rutherford back-scattering spectrometry. Results are discussed by considering the combined effects of growth temperature, smaller ionic radius of the Cr cation compared with the trivalent In ion, doping level, film thickness, the double-target doping technique and peculiarities of the pulsed laser deposition method.

Structural characterization of ultrathin Cr-doped ITO layers deposited by double-target pulsed laser ablation

Science.gov (United States)

Cesaria, Maura; Caricato, Anna Paola; Leggieri, Gilberto; Luches, Armando; Martino, Maurizio; Maruccio, Giuseppe; Catalano, Massimo; Grazia Manera, Maria; Rella, Roberto; Taurino, Antonietta

2011-09-01

In this paper we report on the growth and structural characterization of very thin (20 nm) Cr-doped ITO films, deposited at room temperature by double-target pulsed laser ablation on amorphous silica substrates. The role of Cr atoms in the ITO matrix is carefully investigated with increasing doping content by transmission electron microscopy (TEM). Selected-area electron diffraction, conventional bright field and dark field as well as high-resolution TEM analyses, and energy dispersive x-ray spectroscopy demonstrate that (i) crystallization features occur despite the low growth temperature and small thickness, (ii) no chromium or chromium oxide secondary phases are detectable, regardless of the film doping levels, (iii) the films crystallize as crystalline flakes forming large-angle grain boundaries; (iv) the observed flakes consist of crystalline planes with local bending of the crystal lattice. Thickness and compositional information about the films are obtained by Rutherford back-scattering spectrometry. Results are discussed by considering the combined effects of growth temperature, smaller ionic radius of the Cr cation compared with the trivalent In ion, doping level, film thickness, the double-target doping technique and peculiarities of the pulsed laser deposition method.

Structural characterization of ultrathin Cr-doped ITO layers deposited by double-target pulsed laser ablation

Energy Technology Data Exchange (ETDEWEB)

Cesaria, Maura; Caricato, Anna Paola; Leggieri, Gilberto; Luches, Armando; Martino, Maurizio; Maruccio, Giuseppe [Physics Department, University of Salento, Via Arnesano, 73100 Lecce (Italy); Catalano, Massimo; Manera, Maria Grazia; Rella, Roberto; Taurino, Antonietta, E-mail: antonietta.taurino@le.imm.cnr.it [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, 73100 Lecce (Italy)

2011-09-14

In this paper we report on the growth and structural characterization of very thin (20 nm) Cr-doped ITO films, deposited at room temperature by double-target pulsed laser ablation on amorphous silica substrates. The role of Cr atoms in the ITO matrix is carefully investigated with increasing doping content by transmission electron microscopy (TEM). Selected-area electron diffraction, conventional bright field and dark field as well as high-resolution TEM analyses, and energy dispersive x-ray spectroscopy demonstrate that (i) crystallization features occur despite the low growth temperature and small thickness, (ii) no chromium or chromium oxide secondary phases are detectable, regardless of the film doping levels, (iii) the films crystallize as crystalline flakes forming large-angle grain boundaries; (iv) the observed flakes consist of crystalline planes with local bending of the crystal lattice. Thickness and compositional information about the films are obtained by Rutherford back-scattering spectrometry. Results are discussed by considering the combined effects of growth temperature, smaller ionic radius of the Cr cation compared with the trivalent In ion, doping level, film thickness, the double-target doping technique and peculiarities of the pulsed laser deposition method.

Gasoline from Kumkol deposit petroleum

International Nuclear Information System (INIS)

Nadirov, A.N.; Zhizhin, N.I.; Musaeva, Z.G.

1997-01-01

Samples of gasoline from petroleum of Kumkol deposit are investigated by chromatographic analysis. It is found, that gasoline is characterizing by increased content of iso-paraffin hydrocarbons. (author)

Characterization of 13 and 30 μm thick hydrogenated amorphous silicon diodes deposited over CMOS integrated circuits for particle detection application

International Nuclear Information System (INIS)

Despeisse, M.; Anelli, G.; Commichau, S.; Dissertori, G.; Garrigos, A.; Jarron, P.; Miazza, C.; Moraes, D.; Shah, A.; Wyrsch, N.; Viertel, G.

2004-01-01

We present the experimental results obtained with a novel monolithic silicon pixel detector which consists in depositing a n-i-p hydrogenated amorphous silicon (a-Si:H) diode straight above the readout ASIC (this technology is called Thin Film on ASIC, TFA). The characterization has been performed on 13 and 30 μm thick a-Si:H films deposited on top of an ASIC containing a linear array of high-speed low-noise transimpedance amplifiers designed in a 0.25 μm CMOS technology. Experimental results presented have been obtained with a 600 nm pulsed laser. The results of charge collection efficiency and charge collection speed of these structures are discussed

SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

Science.gov (United States)

Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

2016-05-01

The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

Geochemical characterization of rare earth elements from fluorite deposits of Tangua district - RJ

International Nuclear Information System (INIS)

Coelho, C.E.S.; Dardenne, M.A.

1987-01-01

The Tangua fluorite vein-type deposits are related to an alkaline complex of the same name, and situated in the District of Itaborai, in the State of Rio de Janeiro. The plutonic body of nepheline syenites (Tangua Massif) intrudes basement gneisses, with dykes and sills of trachitic and phonolitic nature of hundreds of meters in length and centimeters to tens of meters in thickness. The fluorite veins are emplaced both in gneisses and alkaline rocks (plutonic body and dykes) in NE-ENE structures created or reactivated during the opening of the South Atlantic Ocean. The geochemical study of rare earth elements reveals that these mineralizations show very low contents in these elements, and a relatively high fractionation spectres. In the deposit environment, four mineralization phases were differenciated, with the first one being considered as the initial solution; the second one characterized by a new europium rich-solution; the third one, representing the evolution of this new solution, but in a reducing environment, with precipitation of pyrite; and the last one, representing a new batch of the initial solution. As a consequence of the REE's and fluid inclusions studies, we are able to suggest an origen by weathering of the country rocks due to superficial meteorics solutions along faults and fractures, that when heated in deep environments, promote lixiviation of silica and fluorine and precipitate the fluorites when their ascending movement comes to an end. (author) [pt

Deposition barium titanate (BaTiO3) doped lanthanum with chemical solution deposition

International Nuclear Information System (INIS)

Iriani, Y.; Nurhadi, N.; Jamaludin, A.

2016-01-01

Deposition of Barium Titanate (BaTiO 3 ) thin films used Chemical Solution Deposition (CSD) method and prepared with spin coater. BaTiO 3 is doped with lanthanum, 1%, 2%, and 3%. The thermal process use annealing temperature 900°C and holding time for 3 hours. The result of characterization with x-ray diffraction (XRD) equipment show that the addition of La 3+ doped on Barium Titanate caused the change of angle diffraction.The result of refine with GSAS software shows that lanthanum have been included in the structure of BaTiO 3 . Increasing mol dopant La 3+ cause lattice parameter and crystal volume become smaller. Characterization result using Scanning Electron Microscopy (SEM) equipment show that grain size (grain size) become smaller with increasing mole dopant (x) La 3+ . The result of characterization using Sawyer Tower methods show that all the samples (Barium Titanante and Barium Titanate doped lanthanum) are ferroelectric material. Increasing of mole dopant La 3+ cause smaller coercive field and remanent polarization increases. (paper)

Characterization of the acidic cold seep emplaced jarositic Golden Deposit, NWT, Canada, as an analogue for jarosite deposition on Mars

Science.gov (United States)

Battler, Melissa M.; Osinski, Gordon R.; Lim, Darlene S. S.; Davila, Alfonso F.; Michel, Frederick A.; Craig, Michael A.; Izawa, Matthew R. M.; Leoni, Lisa; Slater, Gregory F.; Fairén, Alberto G.; Preston, Louisa J.; Banerjee, Neil R.

2013-06-01

Surficial deposits of the OH-bearing iron sulfate mineral jarosite have been observed in several places on Mars, such as Meridiani Planum and Mawrth Vallis. The specific depositional conditions and mechanisms are not known, but by comparing martian sites to analogous locations on Earth, the conditions of formation and, thus, the martian depositional paleoenvironments may be postulated. Located in a cold semi-arid desert ˜100 km east of Norman Wells, Northwest Territories, Canada, the Golden Deposit (GD) is visible from the air as a brilliant golden-yellow patch of unvegetated soil, approximately 140 m × 50 m. The GD is underlain by permafrost and consists of yellow sediment, which is precipitating from seeps of acidic, iron-bearing groundwater. On the surface, the GD appears as a patchwork of raised polygons, with acidic waters flowing from seeps in troughs between polygonal islands. Although UV-Vis-NIR spectral analysis detects only jarosite, mineralogy, as determined by X-ray diffraction and inductively coupled plasma emission spectrometry, is predominantly natrojarosite and jarosite, with hydronium jarosite, goethite, quartz, clays, and small amounts of hematite. Water pH varies significantly over short distances depending on proximity to acid seeps, from 2.3 directly above seeps, to 5.7 several m downstream from seeps within the deposit, and up to 6.5 in ponds proximal to the deposit. Visual observations of microbial filament communities and phospholipid fatty acid analyses confirm that the GD is capable of supporting life for at least part of the year. Jarosite-bearing sediments extend beneath vegetation up to 70 m out from the deposit and are mixed with plant debris and minerals presumably weathered from bedrock and glacial till. This site is of particular interest because mineralogy (natrojarosite, jarosite, hematite, and goethite) and environmental conditions (permafrost and arid conditions) at the time of deposition are conceivably analogous to jarosite

Origin of the Squantum 'Tillite', Massachusetts, USA: Modern Analogs and Implications for Neoproterozoic Climate Models

Science.gov (United States)

Carto, S. L.; Eyles, N.

2009-05-01

A central challenge to the 'Snowball Earth' hypothesis is whether the sedimentary rocks deposited during the Neoproterozoic (c. 750-570 Ma) are glacial tillites that accumulated under global ice sheets during this era. This uncertainty stems from the fact that diamictites are not uniquely glacial in origin, as the slumping and mixing of sediment downslope can also produce diamictites. A key deposit in this debate is the Squantum 'tillite' (ca. 595-570 Ma) preserved in the Boston Basin in Massachusetts, USA, which originated as an arc- related basin within the Avalon island arc terrane during the Neoproterozoic. Detailed field examinations of the Squantum by the author suggest that it owes its origin to the downslope transport of large volumes of unstable volcanic and sedimentary debris from steep basin margin slopes. No evidence of a glacial environment was identified. Thin-section analysis of this deposit has revealed a significant volcanic influence on sedimentation in the form of hitherto unrecognized volcanic lapilli tuff horizons and turbidites consisting of reworked ash in strata associated with Squantum diamictite. These results point to deposition related to tectonic activity and basin development rather than severe global glacial conditions. In light of these results, the Squantum diamictite was compared to the volcaniclastic mass flows deposits exposed along the active Lesser Antilles Arc in the Caribbean. Many of these flows are transported into the adjacent Grenada back-arc Basin by debris flows and turbidity currents resulting in the deposition of volcaniclastic conglomerates, diamictites and thin ash turbidites. Gross stratigraphic and sedimentological similarities of the mass flow facies in the Caribbean can be identified with the Squantum deposits, suggesting that appropriate depositional analogs for the Squantum can be found along the Lesser Antilles Arc. The significance of these results is that they emphasize the importance of detailed field

Characterization of electrochemically deposited films from aqueous and ionic liquid cobalt precursors toward hydrogen evolution reactions

Energy Technology Data Exchange (ETDEWEB)

Dushatinski, Thomas; Huff, Clay; Abdel-Fattah, Tarek M., E-mail: fattah@cnu.edu

2016-11-01

Highlights: • Co films deposition via aqueous and ionic liquid Precursors. • Hydrogen evolution produced from reactive surfaces. • Co deposited films characterized by SEM, AFM, EDX and XRD techniques. - Abstract: Electrodepositions of cobalt films were achieved using an aqueous or an ethylene glycol based non-aqueous solution containing choline chloride (vitamin B4) with cobalt chloride hexahydrate precursor toward hydrogen evolution reactions from sodium borohydride (NaBH{sub 4}) as solid hydrogen feedstock (SHF). The resulting cobalt films had reflectivity at 550 nm of 2.2% for aqueously deposited films (ACoF) and 1.3% for non-aqueously deposited films (NCoF). Surface morphology studied by scanning electron microscopy showed a positive correlation between particle size and thickness. The film thicknesses were tunable between >100 μm and <300 μm for each film. The roughness (Ra) value measurements by Dektak surface profiling showed that the NCoF (Ra = 165 nm) was smoother than the ACoF (Ra = 418 nm). The NCoFs and ACoFs contained only α phase (FCC) crystallites. The NCoFs were crystalline while the ACoFs were largely amorphous from X-ray diffraction analysis. The NCoF had an average Vickers hardness value of 84 MPa as compared to 176 MPa for ACoF. The aqueous precursor has a single absorption maximum at 510 nm and the non-aqueous precursor had three absorption maxima at 630, 670, and 695 nm. The hydrogen evolution reactions over a 1 cm{sup 2} catalytic surface with aqueous NaBH{sub 4} solutions generated rate constants (K) = equal to 4.9 × 10{sup −3} min{sup −1}, 4.6 × 10{sup −3} min{sup −1}, and 3.3 × 10{sup −3} min{sup −1} for ACoF, NCoF, and copper substrate respectively.

Ash Deposit Formation and Deposit Properties. A Comprehensive Summary of Research Conducted at Sandia's Combustion Research Facility

Energy Technology Data Exchange (ETDEWEB)

Larry L. Baxter

2000-08-01

This report summarizes experimental and theoretical work performed at Sandia's Combustion Research Facility over the past eight years on the fate of inorganic material during coal combustion. This work has been done under four broad categories: coal characterization, fly ash formation, ash deposition, and deposit property development. The objective was to provide sufficient understanding of these four areas to be able to predict coal behavior in current and advanced conversion systems. This work has led to new characterization techniques for fuels that provide, for the first time, systematic and species specific information regarding the inorganic material. The transformations of inorganic material during combustion can be described in terms of the net effects of the transformations of these individual species. Deposit formation mechanisms provide a framework for predicting deposition rates for abroad range of particle sizes. Predictions based on these rates many times are quite accurate although there are important exceptions. A rigorous framework for evaluating deposit has been established. Substantial data have been obtained with which to exercise this framework, but this portion of the work is less mature than is any other. Accurate prediction of deposit properties as functions of fuel properties, boiler design, and boiler operating conditions represents the single most critical area where additional research is needed.

Identification and characterization of tsunami deposits off southeast ...

Indian Academy of Sciences (India)

6Institute of Environmental Geosciences, Department of Earth and Environmental Sciences, Pukyong National. University ... challenging topic to be developed in studies on tsunami hazard assessment. Two core ... A tsunami is one of the most terrifying natural hazards .... identify tsunami deposits in a beach environment.

Submarine Landslides and Mass-Transport Deposition in the Nankai fore-arc

Science.gov (United States)

Strasser, M.; Henry, P.; Kanamatsu, T.; Moe, K.; Moore, G. F.; IODP Expedition 333 Scientists

2011-12-01

Multiple lines of evidence exist for a range of sediment mass movement processes within the shallow megasplay fault zone (MSFZ) area and the adjacent slope basin in the outer fore-arc of the Nankai subduction zone, Japan. Diagnostic features observed in 3-D reflection seismic data and in cores from Integrated Ocean Drilling Program (IODP) Expedition 316 document a complex mass movement history spanning at least ˜2.87 million years. Various modes and scales of sediment remobilization can be related to the different morphotectonic settings in which they occurred and allow integration of knowledge on the spatial and temporal distribution of submarine landslides into a holistic reconstruction of the tectonostratigraphic evolution. New data from the most-recent Nankai IODP Expedition 333, which drilled and cored a Pleistocene-to-Holocene succession of the slope-basin seaward of the MSFZ, provides unprecedented details on submarine landslide processes occurring over the last Million year. The slope-basin represents the depocentre for downslope sediment transport and is characterized in 3-D reflection seismic data by several mass-transport deposits (MTDs), including an up to 180 m thick MTD. Here we present D/V Chikyu shipboard results and first post cruise results from Site C0018, including litho- bio- magneto- tephra- and stable isotope-stratigraphy, X-ray computed tomography analysis and physical properties data. Six MTDs were identified from visual core description and X-ray CT-scans. The thickest MTD is also the oldest (emplaced between 0.85 and 1.05 Ma) and it coincides with a lithological transition between a sandy turbidite sequence below, and ash-bearing hemipelagites comprising several MTDs above. Deformation styles within the MTD are heterogeneous: intervals of disturbed sediments are interbedded within intervals inferred to retain original, coherent bedding. In three occurrences the base of the MTD is defined by a shear zone within fine-grained sediments

Stratigraphic implications of uranium deposits

International Nuclear Information System (INIS)

Langford, F.F.

1980-01-01

One of the most consistent characteristics of economic uranium deposits is their restricted stratigraphic distribution. Uraninite deposited with direct igneous affiliation contains thorium, whereas chemical precipitates in sedimentary rocks are characterized by thorium-free primary uranium minerals with vanadium and selenium. In marine sediments, these minerals form low-grade disseminations; but in terrestrial sediments, chiefly fluvial sandstones, the concentration of uranium varies widely, with the high-grade portions constituting ore. Pitchblende vein deposits not only exhibit the same chemical characteristics as the Colorado-type sandstone deposits, but they have a stratigraphically consistent position at unconformities covered by fluvial sandstones. If deposits in such diverse situations have critical features in common, they are likely to have had many features of their origin in common. Thus, vein deposits in Saskatchewan and Australia may have analogues in areas that contain Colorado-type sandstone deposits. In New Mexico, the presence of continental sandstones with peneconformable uranium deposits should also indicate good prospecting ground for unconformity-type vein deposits. All unconformities within the periods of continental deposition ranging from Permian to Cretaceous should have uranium potential. Some situations, such as the onlap of the Abo Formation onto Precambrian basement in the Zuni Mountains, may be directly comparable to Saskatchewan deposition. However, uranium occurrences in the upper part of the Entrada Sandstone suggest that unconformities underlain by sedimentary rocks may also be exploration targets

Characterized the pattern of the material deposition in the HL-2A tokamak

Energy Technology Data Exchange (ETDEWEB)

Cai, Laizhong, E-mail: cailz@swip.ac.cn [Southwestern Institute of Physics, P.O.Box 432, Chengdu, Sichuan 610041 (China); Wang, Jianbao; Wu, Ting; Zeng, Xiaoxiao [Southwestern Institute of Physics, P.O.Box 432, Chengdu, Sichuan 610041 (China); Hai, Ran; Ding, Hongbin [Dalian University of Technology, Dalian, Liaoning 116024 (China)

2017-03-15

Since the divertor geometry of a tokamak has a strong impact on the material erosion and deposition on the wall and HL-2A has a unique divertor configuration, it is necessary to investigate the material deposition pattern in HL-2A although a few results on other tokamaks have already been published. In this paper, tiles retrieved from the vessel are analyzed ex-situ by SIMS, SEM and laser-induced breakdown spectroscopy (LIBS). And deposition behind the lower divertor is in-situ measured by a quartz crystal microbalance (QMB). The deposition in HL-2A displays a complex pattern and clear localization characteristic. The thickness of the deposition layer varies in the range of 0-4μm. And in-situ diagnostic of QMB indicates that the average thickness of the deposition layer per pulse is over ten nanometers. In addition, the results imply that Si, Fe and D have different behaviors during the material deposition in HL-2A.

Structural and Magnetic Properties of Mn doped ZnO Thin Film Deposited by Pulsed Laser Deposition

KAUST Repository

Baras, Abdulaziz

2011-07-01

Diluted magnetic oxide (DMO) research is a growing field of interdisciplinary study like spintronic devices and medical imaging. A definite agreement among researchers concerning the origin of ferromagnetism in DMO has yet to be reached. This thesis presents a study on the structural and magnetic properties of DMO thin films. It attempts to contribute to the understanding of ferromagnetism (FM) origin in DMO. Pure ZnO and Mn doped ZnO thin films have been deposited by pulsed laser deposition (PLD) using different deposition conditions. This was conducted in order to correlate the change between structural and magnetic properties. Structural properties of the films were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The superconducting quantum interference device (SQUID) was used to investigate the magnetic properties of these films. The structural characterizations showed that the quality of pure ZnO and Mn doped ZnO films increased as oxygen pressure (PO) increased during deposition. All samples were insulators. In Mn doped films, Mn concentration decreased as PO increased. The Mn doped ZnO samples were deposited at 600˚C and oxygen pressure from 50-500mTorr. All Mn doped films displayed room temperature ferromagnetism (RTFM). However, at 5 K a superparamagnetic (SPM) behavior was observed in these samples. This result was accounted for by the supposition that there were secondary phase(s) causing the superparamagnetic behavior. Our findings hope to strengthen existing research on DMO origins and suggest that secondary phases are the core components that suppress the ferromagnetism. Although RTFM and SPM at low temperature has been observed in other systems (e.g., Co doped ZnO), we are the first to report this behavior in Mn doped ZnO. Future research might extend the characterization and exploration of ferromagnetism in this system.

Pulsed laser deposition and characterization of cellulase thin films

Science.gov (United States)

Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

2013-08-01

Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

Electrical characterization of low temperature deposited oxide films ...

Indian Academy of Sciences (India)

Unknown

electronics on the same substrate (Water and Chu 2002). Plasma enhanced chemical vapour deposition (PECVD) .... sion in depletion region is due to the presence of inter- face traps. The total capacitance in inversion ... The conductance technique is used to deter- mine the interface state density throughout the depletion.

The fabrication and characterization of an ex situ plated lead film electrode prepared with the use of a reversibly deposited mediator metal

International Nuclear Information System (INIS)

Tyszczuk, Katarzyna

2011-01-01

Research highlights: → The lead film electrode prepared with use of the mediator metal was elaborated. → The lead-based sensors were characterized by optical and voltammetric methods. → The adsorptive system of folic acid was employed to investigate a new electrode. → The application of the mediator metal improved properties of a lead film electrode. - Abstract: In this paper an ex situ plated lead film electrode prepared with use of the mediator metal (Zn) was elaborated. The electrochemical method for lead film formation is based on a co-deposition of a metal of interest (Pb) with a reversibly deposited mediator metal (Zn) and then on an oxidation of zinc and further deposition of lead by the appropriate potential. This serves to increase the density of islands of lead atoms, promoting lead film growth. The lead-based sensors were characterized by optical method (atomic force microscopy (AFM)) and as well as cyclic, linear sweep and square wave voltammetry. The adsorptive system of folic acid was employed to investigate the electrochemical characteristics a novel type of lead film electrode. Well-formed stripping peaks and a linear dependence of the stripping current on the folic acid concentration were observed on the lead film electrode prepared with use of the mediator metal while comparative measurements attempted with the lead film electrode prepared without use of the mediator metal were unsuccessful.

Optoelectronic Characterization of Ta-Doped ZnO Thin Films by Pulsed Laser Deposition.

Science.gov (United States)

Koo, Horng-Show; Peng, Jo-Chi; Chen, Mi; Chin, Hung-I; Chen, Jaw-Yeh; Wu, Maw-Kuen

2015-11-01

Transparent conductive oxide of Ta-doped ZnO (TZO) film with doping amount of 3.0 wt% have been deposited on glass substrates (Corning Eagle XG) at substrate temperatures of 100 to 500 degrees C by the pulsed laser deposition (PLD) technique. The effect of substrate temperature on the structural, optical and electronic characteristics of Ta-doped ZnO (TZO) films with 3.0 wt% dopant of tantalum oxide (Ta2O5) was measured and demonstrated in terms of X-ray diffraction (XRD), ultraviolet-visible spectrometer (UV-Vis), four-probe and Hall-effect measurements. X-ray diffraction pattern shows that TZO films grow in hexagonal crystal structure of wurtzite phase with a preferred orientation of the crystallites along (002) direction and exhibits better physical characteristics of optical transmittance, electrical conductivity, carrier concentration and mobility for the application of window layer in the optoelectronic devices of solar cells, OLEDs and LEDs. The lowest electrical resistivity (ρ) and the highest carrier concentration of the as-deposited film deposited at 300 degrees C are measured as 2.6 x 10(-3) Ω-cm and 3.87 x 10(-20) cm(-3), respectively. The highest optical transmittance of the as-deposited film deposited at 500 degrees C is shown to be 93%, compared with another films deposited below 300 degrees C. It is found that electrical and optical properties of the as-deposited TZO film are greatly dependent on substrate temperature during laser ablation deposition.

Immunoglobulin derived depositions in the nervous system: novel mass spectrometry application for protein characterization in formalin-fixed tissues.

Science.gov (United States)

Rodriguez, Fausto J; Gamez, Jeffrey D; Vrana, Julie A; Theis, Jason D; Giannini, Caterina; Scheithauer, Bernd W; Parisi, Joseph E; Lucchinetti, Claudia F; Pendlebury, William W; Bergen, H Robert; Dogan, Ahmet

2008-10-01

Proteinaceous deposits are occasionally encountered in surgically obtained biopsies of the nervous system. Some of these are amyloidomas, although the precise nature of other cases remains uncertain. We studied 13 cases of proteinaceous aggregates in clinical specimens of the nervous system. Proteins contained within laser microdissected areas of interest were identified from tryptic peptide sequences by liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS). Immunohistochemical studies for immunoglobulin heavy and light chains and amyloidogenic proteins were performed in all cases. Histologically, the cases were classified into three groups: 'proteinaceous deposit not otherwise specified' (PDNOS) (n=6), amyloidoma (n=5), or 'intracellular crystals' (n=2). LC-MS/MS demonstrated the presence of lambda, but not kappa, light chain as well as serum amyloid P in all amyloidomas. lambda-Light-chain immunostaining was noted in amyloid (n=5), although demonstrable monotypic lymphoplasmacytic cells were seen in only one case. Conversely, in PDNOS kappa, but not lambda, was evident in five cases, both light chains being present in a single case. In three cases of PDNOS, a low-grade B-cell lymphoma consistent with marginal zone lymphoma was present in the brain specimen (n=2) or spleen (n=1). Lastly, in the 'intracellular crystals' group, the crystals were present within CD68+ macrophages in one case wherein kappa-light chain was found by LC-MS/MS only; the pathology was consistent with crystal-storing histiocytosis. In the second case, the crystals contained immunoglobulin G within CD138+ plasma cells. Our results show that proteinaceous deposits in the nervous system contain immunoglobulin components and LC-MS/MS accurately identifies the content of these deposits in clinical biopsy specimens. LC-MS/MS represents a novel application for characterization of these deposits and is of diagnostic utility in addition to standard immunohistochemical analyses.

Effects of deposition period on the chemical bath deposited Cu4SnS4 thin films

International Nuclear Information System (INIS)

Kassim, Anuar; Wee Tee, Tan; Soon Min, Ho.; Nagalingam, Saravanan

2010-01-01

Cu 4 SnS 4 thin films were prepared by simple chemical bath deposition technique. The influence of deposition period on the structural, morphological and optical properties of films was studied. The films were characterized using X-ray diffraction, atomic force microscopy and UV-Vis Spectrophotometer. X-ray diffraction patterns indicated that the films were polycrystalline with prominent peak attributed to (221) plane of orthorhombic crystal structure. The films prepared at 80 min showed significant increased in the intensity of all diffractions. According to AFM images, these films indicated that the surface of substrate was covered completely. The obtained films also produced higher absorption characteristics when compared to the films prepared at other deposition periods based on optical absorption studies. The band gap values of films deposited at different deposition periods were in the range of 1.6-2.1 eV. Deposition for 80 min was found to be the optimum condition to produce good quality thin films under the current conditions. (author).

Low-pressure c-BN deposition - is a CVD process possible?

International Nuclear Information System (INIS)

Haubner, R.; Tang, X.

2001-01-01

Since the low-pressure diamond deposition was discovered in 1982 there is a high interest to find a similar process for the c-BN synthesis. A review about the c-BN deposition process as well as its characterization is given. Experiments with a simple chemical vapor deposition(CVD) reactor using tris(dimethylamino)borane as precursor were carried out. In a cold-wall reactor substrates were heated up by high-frequency. Argon was used as protecting and carrying the precursor, it was saturated with tris(dimethylamino)borane (precursor) according to its vapor pressure and transports the pressure to the hot substrate, where deposition occurs. WC-Co hardmetal plates containing 6 wt. % Co, Mo and Si were used as substrates. Various BN layers were deposited and characterized. X-ray diffraction, IR-spectroscopy and SIMS indicate that BN-coatings containing c-BN were deposited. However a final verification of c-BN crystallites by TEM investigations was not possible till now. (nevyjel)

Characterization of DC magnetron plasma in Ar/Kr/N2 mixture during deposition of (Cr,Al)N coating

International Nuclear Information System (INIS)

Bobzin, K; Bagcivan, N; Theiß, S; Brugnara, R; Bibinov, N; Awakowicz, P

2017-01-01

Reactive sputter deposition of (Cr,Al)N coatings in DC magnetron plasmas containing Ar/Kr/N 2 mixtures is characterized by applying a combination of voltage–current measurement, optical emission spectroscopy (OES) and numerical simulation. Theoretical and experimental methods supplement each other and their combination permits us to obtain the most reliable information about the processes by physical vapor deposition. Gas temperature ( T g ) and plasma parameters, namely electron density n e and electron temperature T e are determined by spatial resolved measurements of molecular nitrogen photoemission. Steady-state densities of Cr and Al atoms are measured using OES. The sputtering of Cr and Al atoms is simulated using the TRIDYN code, measured electric current and applied voltage. Transport of sputtered atoms through the plasma volume is simulated by adopting a Monte-Carlo code. In order to quantify the ‘poisoning’ of the target surface with nitrogen, simulated steady state densities of Al and Cr atoms at different states of poisoning and at different distances from the target are compared with the measured densities. In addition, simulated fluxes of Cr and Al atoms to the substrate are compared with the measured deposition rates of the (Cr,Al)N coating. (paper)

Electrodéposition et la caractérisation de nanofilms palladium sur Au (111) pour le stockage d'hydrogène Electro-deposition and characterization of palladium nanofilms on Au (111) for hydrogen storage

OpenAIRE

Wang , Liang

2012-01-01

This thesis focused on electro-deposition, characterization andhydrogen strorage of ultrathin palladium film over Au(111). Theelectrochemical characterization of the nanofilms in sulphuric mediumshows well-defined features evolving with the deposit thickness. Wecould assign each peak to a specific reaction, in agreement with thegrowth mechanisms revealed by in situ SXRD measurements. Thepseudomorphic growth of the 1st layer firstly undergoes an adsorptionstep, followed by nucleation and growt...

Characterization of Fe-based alloy coating deposited by supersonic plasma spraying

International Nuclear Information System (INIS)

Piao, Zhong-yu; Xu, Bin-shi; Wang, Hai-dou; Wen, Dong-hui

2013-01-01

Highlights: • Fe-based coating exhibited few oxides, high density and bond strength. • Amorphous/nanocrystalline phases were found in the coating. • Formation mechanism of excellent coating was investigated. -- Abstract: The objective of the present study is to characterize the Fe-based alloy coating deposited by the supersonic plasma spraying process. The condition of the melting particles was in situ monitored. The microstructure of the coating was examined by scanning electron microscope and high resolution transmission electron microscope. The phase composition was examined by X-ray diffraction. The microhardness and porosity were also measured, respectively. Results show the prepared coatings have excellent properties, such as few oxides, high microhardness and a low porosity amount. At the same time, a mass of amorphous/nanocrystalline phases was found in the coating. The mechanism of the formation of amorphous/nanocrystalline phases was investigated. The appropriate material composition of spraying material and flash set process of plasma spraying are the key factors. Moreover, the mechanism for oxidation resistance is also investigated, where the separation between melting metal and oxygen by the formation of SiO 2 films is the key factor

Characterization of hafnium oxide resistive memory layers deposited on copper by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Briggs, B.D.; Bishop, S.M. [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States); Leedy, K.D. [Air Force Research Laboratory, 2241 Avionics Circle, Wright Patterson Air Force Base, Dayton, OH 45433 (United States); Cady, N.C., E-mail: ncady@albany.edu [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States)

2014-07-01

Hafnium oxide-based resistive memory devices have been fabricated on copper bottom electrodes. The HfO{sub x} active layers in these devices were deposited by atomic layer deposition (ALD) at 250 °C with tetrakis(dimethylamido)hafnium(IV) as the metal precursor and an O{sub 2} plasma as the reactant. Depth profiles of the HfO{sub x} by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a copper concentration on the order of five atomic percent throughout the HfO{sub x} film. In addition to the Cu doped HfO{sub x}, a thin layer (20 nm) of Cu{sub x}O is present at the surface. This surface layer is believed to have formed during the ALD process, and greatly complicates the analysis of the switching mechanism. The resistive memory structures fabricated from the ALD HfO{sub x} exhibited non-polar resistive switching, independent of the top metal electrode (Ni, Pt, Al, Au). Resistive switching current voltage (I–V) curves were analyzed using Schottky emission and ionic hopping models to gain insight into the physical mechanisms underpinning the device behavior. During the forming process it was determined that, at voltages in excess of 2.5 V, an ionic hopping model is in good agreement with the I–V data. The extracted ion hopping distance ∼ 4 Å was within the range of interatomic spacing of HfO{sub 2} during the forming process consistent with ionic motion of Cu{sup 2+} ions. Lastly the on state I–V data was dominated at larger voltages by Schottky emission with an estimated barrier height of ∼ 0.5 eV and a refractive index of 2.59. The consequence of the Schottky emission analysis indicates the on state resistance to be a product of a Pt/Cu{sub 2}O/Cu filament(s)/Cu{sub 2}O/Cu structure. - Highlights: • HfO{sub 2} was grown via atomic layer deposition at 250 and 100 °C on Cu substrates. • A Cu{sub 2}O surface layer and Cu doping were observed in post-deposition of HfO{sub 2}. • Resistive memory devices were fabricated and

Pulsed laser deposition and characterization of multilayer metal-carbon thin films

Energy Technology Data Exchange (ETDEWEB)

Siraj, K., E-mail: khurram.uet@gmail.com [Advance Physics Laboratory, Department of Physics, University of Engineering and Technology, Lahore (Pakistan); Khaleeq-ur-Rahman, M.; Rafique, M.S.; Munawar, M.Z. [Advance Physics Laboratory, Department of Physics, University of Engineering and Technology, Lahore (Pakistan); Naseem, S.; Riaz, S. [Center for Solid State Physics, University of Punjab, Lahore (Pakistan)

2011-05-15

Cobalt-DLC multilayer films were deposited with increasing content of cobalt, keeping carbon content constant by pulsed laser deposition technique. A cobalt free carbon film was also deposited for comparison. Excimer laser was employed to ablate the materials onto silicon substrate, kept at 250 deg. C, while post-deposition annealing at 400 deg. C was also performed in situ. The formation of cobalt grains within the carbon matrix in Co-DLC films can be seen through scanning electron and atomic force micrographs while no grains on the surface of the cobalt-free DLC film were observed. Raman spectra of all the films show D- and G-bands, which is a confirmation that the films are DLC in nature. According to Vibrating sample magnetometer (VSM) measurements, the DLC films with cobalt revealed ferromagnetic behaviour whereas the cobalt free DLC film exhibited diamagnetic behaviour. The pure DLC film also shows ferromagnetic nature when diamagnetic background is subtracted. Spectroscopic Ellipsometry (SE) analysis showed that the optical band gaps, refractive indices and extinction coefficients of Co-DLC films can be effectively tuned with increasing content of cobalt.

Pulsed laser deposition and characterization of multilayer metal-carbon thin films

International Nuclear Information System (INIS)

Siraj, K.; Khaleeq-ur-Rahman, M.; Rafique, M.S.; Munawar, M.Z.; Naseem, S.; Riaz, S.

2011-01-01

Cobalt-DLC multilayer films were deposited with increasing content of cobalt, keeping carbon content constant by pulsed laser deposition technique. A cobalt free carbon film was also deposited for comparison. Excimer laser was employed to ablate the materials onto silicon substrate, kept at 250 deg. C, while post-deposition annealing at 400 deg. C was also performed in situ. The formation of cobalt grains within the carbon matrix in Co-DLC films can be seen through scanning electron and atomic force micrographs while no grains on the surface of the cobalt-free DLC film were observed. Raman spectra of all the films show D- and G-bands, which is a confirmation that the films are DLC in nature. According to Vibrating sample magnetometer (VSM) measurements, the DLC films with cobalt revealed ferromagnetic behaviour whereas the cobalt free DLC film exhibited diamagnetic behaviour. The pure DLC film also shows ferromagnetic nature when diamagnetic background is subtracted. Spectroscopic Ellipsometry (SE) analysis showed that the optical band gaps, refractive indices and extinction coefficients of Co-DLC films can be effectively tuned with increasing content of cobalt.

Deposition and characterization of thin films of materials with application in cathodes for lithium rechargeable micro batteries

International Nuclear Information System (INIS)

Lopez I, J.

2007-01-01

In this thesis work is reported the deposition and characterization of thin films of materials of the type LiMO 2 , with M=Co and Ni, which have application in cathodes for micro-batteries of lithium ions. In the last years some investigators have reported that the electrochemical operation of the lithium ions batteries it can improve recovering the cathode, in bundle form, with some metal oxides as the Al 2 O 3 ; for that the study of the formation of thin films in bilayer form LiMO 2 /AI 2 O 3 is of interest in the development of lithium ions micro batteries. The thin films were deposited using the laser ablation technique studying the effect of some deposit parameters in the properties of the one formed material, as: laser fluence, substrate temperature and working atmosphere, with the purpose of optimizing it. In the case of the LiCoO 2 it was found that to use an inert atmosphere of argon allows to obtain the material with the correct composition. Additionally, with the use of a temperature in the substrate of 150 C is possible to obtain to the material with certain crystallinity grade that to the subjected being to a post-deposit thermal treatment at 300 C for three hours, it gives as result a totally crystalline material. In the case of the thin films of LiNiO 2 , it was necessary to synthesize the oxide starting from a reaction of solid state among nickel oxide (NiO) and lithium oxide (Li 2 O) obtaining stoichiometric LiNiO 2 . For the formation of the thin films of LiNiO 2 it was used an argon atmosphere and the laser fluence was varied, the deposits were carried out to two different substrates temperatures, atmosphere and 160 C. In both cases the material it was recovered with an alumina layer, found that this layer didn't modify the structural properties of the base oxide (LiCoO 2 and LiNiO 2 ). (Author)

Whole body amyloid deposition imaging by 123I-SAP scintigraphy

NARCIS (Netherlands)

van Rheenen, Ronald; Glaudemans, Andor; Hazenberg, Bouke

2011-01-01

Amyloidosis is the name of a group of diseases characterized by extracellular deposition of amyloid fibrils. Deposition of amyloid can be localized or systemic. The 123I-SAP-scan can be used to image extent and distribution of amyloid deposition in patients with systemic AA, AL and ATTR amyloidosis.

Deposits formed by ascending vein water (3 type)

International Nuclear Information System (INIS)

Komarova, G.V.

1980-01-01

Deposits formed by ascending vein waters (3 type), are considered using uranium-bitumen deposit in red-coloured continental sediments of Permo-Triassic as an example. Geological-structural and hydrogeological conditions of mineralization localization and conditions of deposit formation are discussed. Mineralogic-geochemical features and morphology of ore bodies are characterized. Attention is paid to the problem of epigenetic zone in ore-containing rocks and stages of its formation [ru

Silicification of quartz arenites overlain by volcaniclastic deposits: an alternative to silcrete formation

Czech Academy of Sciences Publication Activity Database

Malý, Karel; Cajz, Vladimír; Adamovič, Jiří; Zachariáš, J.

2006-01-01

Roč. 57, č. 6 (2006), s. 461-472 ISSN 1335-0552 R&D Projects: GA AV ČR IAA3013302 Institutional research plan: CEZ:AV0Z30130516 Keywords : quartzite * silcrete * dealkalization * Ohře Rift * silicification * dense tuff * quartz overgrowths Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.364, year: 2006 http://www.geologicacarpathica.sk/src/main.php

Piezoelectric characterization of Pb(Zr,Ti)O3 thin films deposited on metal foil substrates by dip coating

Science.gov (United States)

Hida, Hirotaka; Hamamura, Tomohiro; Nishi, Takahito; Tan, Goon; Umegaki, Toshihito; Kanno, Isaku

2017-10-01

We fabricated the piezoelectric bimorphs composed of Pb(Zr,Ti)O3 (PZT) thin films on metal foil substrates. To efficiently inexpensively manufacture piezoelectric bimorphs with high flexibility, 1.2-µm-thick PZT thin films were directly deposited on both surfaces of 10- and 20-µm-thick bare stainless-steel (SS) foil substrates by dip coating with a sol-gel solution. We confirmed that the PZT thin films deposited on the SS foil substrates at 500 °C or above have polycrystalline perovskite structures and the measured relative dielectric constant and dielectric loss were 323-420 and 0.12-0.17, respectively. The PZT bimorphs were demonstrated by comparing the displacements of the cantilever specimens driven by single- and double-side PZT thin films on the SS foil substrates under the same applied voltage. We characterized the piezoelectric properties of the PZT bimorphs and the calculated their piezoelectric coefficient |e 31,f| to be 0.3-0.7 C/m2.

Cover sequences at the northern margin of the Antongil Craton, NE Madagascar

Science.gov (United States)

Bauer, W.; Walsh, G.J.; De Waele, B.; Thomas, Ronald J.; Horstwood, M.S.A.; Bracciali, L.; Schofield, D.I.; Wollenberg, U.; Lidke, D.J.; Rasaona, I.T.; Rabarimanana, M.H.

2011-01-01

The island of Madagascar is a collage of Precambrian, generally high-grade metamorphic basement domains, that are locally overlain by unmetamorphosed sedimentary rocks and poorly understood low-grade metasediments. In the Antalaha area of NE Madagascar, two distinct cover sequences rest on high-grade metamorphic and igneous basement rocks of the Archaean Antongil craton and the Neoproterozoic Bemarivo belt. The older of these two cover sequences, the Andrarona Group, consists of low-grade metasedimentary rocks. The younger sequence, the newly defined Ampohafana Formation, consists of unmetamorphosed sedimentary rocks. The Andrarona Group rests on Neoarchaean granites and monzogranites of the Antongil craton and consists of a basal metagreywacke, thick quartzites and an upper sequence of sericite-chlorite meta-mudstones, meta-sandstones and a volcaniclastic meta-sandstone. The depositional age of the volcaniclastic meta-sandstone is constrained in age by U–Pb laser-ablation ICP-MS analyses of euhedral zircons to 1875 ± 8 Ma (2σ). Detrital zircons of Archaean and Palaeoproterozoic age represent an input from the Antongil craton and a newly defined Palaeoproterozoic igneous unit, the Masindray tonalite, which underlies the Andrarona Group, and yielded a U–Pb zircon age of 2355 ± 11 Ma (2σ), thus constraining the maximum age of deposition of the basal part of the Andrarona Group. The Andrarona Group shows a low-grade metamorphic overprint in the area near Antalaha; illite crystallinity values scatter around 0.17°Δ2Θ CuKα, which is within the epizone. The Ampohafana Formation consists of undeformed, polymict conglomerate, cross-bedded sandstone, and red mudstone. An illite crystallinity value of >0.25°Δ2Θ CuKα obtained from the rocks is typical of the diagenetic zone. Occurrences of rhyodacite pebbles in the Ampohafana Formation and the intrusion of a basaltic dyke suggest a deposition in a WSW-ENE-trending graben system during the opening of the Indian

Volcanogenic Turonian and epiclastics of senonian in the Timok magmatic complex between Bor and the Tupižnica mountain, eastern Serbia

Directory of Open Access Journals (Sweden)

Đorđević Miodrag

2005-01-01

Full Text Available In the light of the findings presented in this paper, among the volcanic products of the Upper Cretaceous, referred to as "the first volcanic phase" (Drovenik, 1961, two lithostratigraphic units can be singled out within the Timok Magmatic Complex (TMC: - The lower one, consisting of volcanogenic, subaerial, dominantly hornblende andésite volcaniclastic, formed on land, and less abundant volcanic and sub-volcanic-hypoabyssal rocks. It is the main source of sulfide mine­ralization in Bor. It was formed before the Upper Turonian and consists of hornblende andésite and occasionally low biotite. Minor constituents are biotite-hornblende dacite and some andésite and dacite materials con­taining augite in addition to hornblende and biotite. - The upper one, from the Upper Turonian period when the volcanic activity of the region had ended, is marine deposited and epiclastic. Intercalated with Senonian marls, it is composed of land deposited Turonian volcanogenic material of all generations. Fresh material mostly consisting of hornblende andésite volcanoclastics prevails in it. Fresh epiclastics include ore mineral epiclasts. Epiclastics composed of epiclasts of hydro thermally altered rocks were observed which also include ore epiclasts. The ore epiclasts originate from copper ore. The boundary between the volcanogenic Turonian and the epiclastic deposits is a well-recognized unconformity. Table 1 in the text summarizes the main characteristics of the Turonian volcanogenic rocks, primarily those of volcaniclastics, as well as those of epiclastic deposits.

Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

Science.gov (United States)

Bahlburg, H.; Breitkreuz, C.

The geodynamic evolution of the Paleozoic continental margin of Gondwana in the region of the southern Central Andes is characterized by the westward progression of orogenic basin formation through time. The Ordovician basin in the northwest Argentinian Cordillera Oriental and Puna originated as an Early Ordovician back-arc basin. The contemporaneous magmatic arc of an east-dipping subduction zone was presumably located in northern Chile. In the back-arc basin, a ca. 3500 meter, fining-up volcaniclastic apron connected to the arc formed during the Arenigian. Increased subsidence in the late Arenigian allowed for the accomodation of large volumes of volcaniclastic turbidites during the Middle Ordovician. Subsidence and sedimentation were caused by the onset of collision between the para-autochthonous Arequipa Massif Terrane (AMT) and the South American margin at the Arenigian-Llanvirnian transition. This led to eastward thrusting of the arc complex over its back-arc basin and, consequently, to its transformation into a marine foreland basin. As a result of thrusting in the west, a flexural bulge formed in the east, leading to uplift and emergence of the Cordillera Oriental shelf during the Guandacol Event at the Arenigian-Llanvirnian transition. The basin fill was folded during the terminal collision of the AMT during the Oclóyic Orogeny (Ashgillian). The folded strata were intruded post-tectonically by the presumably Silurian granitoids of the "Faja Eruptiva de la Puna Oriental." The orogeny led to the formation of the positive area of the Arco Puneño. West of the Arco Puneño, a further marine basin developed during the Early Devonian, the eastern shelf of which occupied the area of the Cordillera Occidental, Depresión Preandina, and Precordillera. The corresponding deep marine turbidite basin was located in the region of the Cordillera de la Costa. Deposition continued until the basin fill was folded in the early Late Carboniferous Toco Orogeny. The basin

Characterization of noble metals deposits and oxides in conditions of BWR reactors

International Nuclear Information System (INIS)

Arganis J, C.R.; Aguilar T, J.A.; Contreras R, A.

2008-01-01

The oxides deposited on steel 304l under normal chemistry conditions (NWC) and hydrogen chemistry (HWC) with presence of Zn, being that the first ones present hexagonal oxides of Hematite and the second bipyramidal crystals possibly Magnetite with traces of Zn. Deposits of Pt on the oxidized surfaces under NWC conditions were obtained, being glasses from 2 to 4 μm and Pt-Rh deposits were obtained on the oxidized surfaces in presence of Zn, by its size its were not possible to observe them by scanning electron microscopy. The kinetics of the surfaces of Hematite and of the deposits of Pt it was measured by means of the Tafel extrapolation technique, being proven the catalytic effect of the Pt, even in sizes of 11 μm. (Author)

Water evaporation in silica colloidal deposits.

Science.gov (United States)

Peixinho, Jorge; Lefèvre, Grégory; Coudert, François-Xavier; Hurisse, Olivier

2013-10-15

The results of an experimental study on the evaporation and boiling of water confined in the pores of deposits made of mono-dispersed silica colloidal micro-spheres are reported. The deposits are studied using scanning electron microscopy, adsorption of nitrogen, and adsorption of water through attenuated total reflection-infrared spectroscopy. The evaporation is characterized using differential scanning calorimetry and thermal gravimetric analysis. Optical microscopy is used to observe the patterns on the deposits after evaporation. When heating at a constant rate and above boiling temperature, the release of water out of the deposits is a two step process. The first step is due to the evaporation and boiling of the surrounding and bulk water and the second is due to the desorption of water from the pores. Additional experiments on the evaporation of water from membranes having cylindrical pores and of heptane from silica deposits suggest that the second step is due to the morphology of the deposits. Copyright © 2013 Elsevier Inc. All rights reserved.

Electrochemical deposition and characterization of platinum on carbon paper and Ni foam

CSIR Research Space (South Africa)

Louw, E

2013-04-01

Full Text Available There are various methods used to prepare fuel cell (FC) catalysts. The electrochemical deposition method is well known for the fabrication of nanostructured catalysts for energy materials. Electrochemical atomic layer deposition (ECALD) method...

Categorizing vitric lithofacies on seamounts: implications for recognizing deep-marine pyroclastic deposits

Science.gov (United States)

Portner, R. A.; Clague, D. A.

2011-12-01

lithofacies has a structureless to 'swirled' habit and interdigitating bedding contacts where it is host to matrix-supported subround vitric lapilli with low-vesicularity. These rare globules have mud-filled embayments, bubbles and quench-cracks, jig-saw fit texture, and fluidal morphologies suggesting a pepperitic origin. Laterally, bottom current reworked lithofacies grade into fine-to medium-grained ash lithofacies proximal to volcanic-constructional landforms. These landforms have broad morphologies with subdued slopes and are interpreted as source vents. Lithofacies generated from these vents invariably contain an abundance of low-vesicular limu-o-Pele'- or highly-vesicular round lapilli. Units are coarse-tail reverse to normal graded and crudely planar laminated or structureless. Locally, basal contacts are erosive. This facies is interpreted as fall-out from particle lofting or high-density gravity flows generated by explosive eruptions. By combining high-resolution bathymetric mapping and sampling with post-cruise geochemical and petrographic examination, we outline a previously unrecognized diversity to seamount-capping vitriclastic deposits. This approach will be useful for studies focused on deciphering explosive origins of deep-marine volcaniclastic deposits.

Geochemical characterization of the Jurassic Amran deposits from Sharab area (SW Yemen): Origin of organic matter, paleoenvironmental and paleoclimate conditions during deposition

Science.gov (United States)

Hakimi, Mohammed Hail; Abdullah, Wan Hasiah; Makeen, Yousif M.; Saeed, Shadi A.; Al-Hakame, Hitham; Al-Moliki, Tareq; Al-Sharabi, Kholah Qaid; Hatem, Baleid Ali

2017-05-01

Calcareous shales and black limestones of the Jurassic Amran Group, located in the Sharab area (SW Yemen), were analysed based on organic and inorganic geochemical methods. The results of this study were used to reconstruct the paleoenvironmental and paleoclimatic conditions during Jurassic time and their relevance to organic matter enrichment during deposition of the Amran calcareous shale and black limestone deposits. The analysed Amran samples have present-day TOC and Stotal content values in the range of 0.25-0.91 wt % and 0.59-4.96 wt %, respectively. The relationship between Stotal and TOC contents indicates that the Jurassic Amran deposits were deposited in a marine environment as supported by biomarker environmental indicators. Biomarker distributions also reflect that the analysed Amran deposits received high contributions of marine organic matter (e.g., algal and microbial) with minor amount of land plant source inputs. Low oxygen (reducing) conditions during deposition of the Jurassic Amran deposits are indicated from low Pr/Ph values and relatively high elemental ratios of V/Ni and V/(V + Ni). Enrichment in the pyrite grains and very high DOPT and high Fe/Al ratios further suggest reducing bottom waters. This paleo-redox (i.e., reducing) conditions contributed to preservation of organic matter during deposition of the Jurassic Amran deposits. Semi-arid to warm climatic conditions are also evidenced during deposition of the Amran sediments and consequently increased biological productivity within the photic zone of the water column during deposition. Therefore, the increased bio-productivity in combination with good preservation of organic matter identified as the major mechanisms that gave rise to organic matter enrichment. This contradicts with the low organic matter content of the present-day TOC values of less than 1%. The biomarker maturity data indicate that the analysed Amran samples are of high thermal maturity; therefore, the low present-day TOC

Characterization and methanol electrooxidation studies of Pt(111)/Os surfaces prepared by spontaneous deposition.

Science.gov (United States)

Johnston, Christina M; Strbac, Svetlana; Lewera, Adam; Sibert, Eric; Wieckowski, Andrzej

2006-09-12

Catalytic activity of the Pt(111)/Os surface toward methanol electrooxidation was optimized by exploring a wide range of Os coverage. Various methods of surface analyses were used, including electroanalytical, STM, and XPS methods. The Pt(111) surface was decorated with nanosized Os islands by spontaneous deposition, and the Os coverage was controlled by changing the exposure time to the Os-containing electrolyte. The structure of Os deposits on Pt(111) was characterized and quantified by in situ STM and stripping voltammetry. We found that the optimal Os surface coverage of Pt(111) for methanol electrooxidation was 0.7 +/- 0.1 ML, close to 1.0 +/- 0.1 Os packing density. Apparently, the high osmium coverage Pt(111)/Os surface provides more of the necessary oxygen-containing species (e.g., Os-OH) for effective methanol electrooxidation than the Pt(111)/Os surfaces with lower Os coverage (vs e.g., Ru-OH). Supporting evidence for this conjecture comes from the CO electrooxidation data, which show that the onset potential for CO stripping is lowered from 0.53 to 0.45 V when the Os coverage is increased from 0.2 to 0.7 ML. However, the activity of Pt(111)/Os for methanol electrooxidation decreases when the Os coverage is higher than 0.7 +/- 0.1 ML, indicating that Pt sites uncovered by Os are necessary for sustaining significant methanol oxidation rates. Furthermore, osmium is inactive for methanol electrooxidation when the platinum substrate is absent: Os deposits on Au(111), a bulk Os ingot, and thick films of electrodeposited Os on Pt(111), all compare poorly to Pt(111)/Os. We conclude that a bifunctional mechanism applies to the methanol electrooxidation similarly to Pt(111)/Ru, although with fewer available Pt sites. Finally, the potential window for methanol electrooxidation on Pt(111)/Os was observed to shift positively versus Pt(111)/Ru. Because of the difference in the Os and Ru oxophilicity under electrochemical conditions, the Os deposit provides fewer

Characterization and dissolution studies of Bruce Unit 3 steam generator secondary side deposits

International Nuclear Information System (INIS)

Semmler, J.

1998-01-01

The physical and chemical properties of secondary side steam generator deposits in the form of powder and flake obtained from Bruce Nuclear Generating Station A (BNGS A) Unit 3 were studied. The chemical phases present in both types of deposits, collected prior to the 1994 chemical cleaning during the pre-clean water lancing campaign, were magnetite (Fe 3 O 4 ), metallic copper (Cu), hematite (Fe 2 O 3 ) and cuprous oxide (Cu 2 O). The major difference between the chemical composition of the powder and the flake was the presence of zinc silicate (Zn 2 SiO 4 ) and several unidentified silicate phases containing Ca, Al, Mn, and Mg in the flake. The flake deposit had high hardness values, high electrical resistivity, low porosity and a lower dissolution rate in the EPRI-SGOG (Electric Power Research Institute-Steam Generator Owner's Group) chemical cleaning solvents compared to the powder deposit. Differences in the deposit properties after chemical cleaning of the Unit 3 steam generators and after laboratory cleaning were noted. The presence of silicates in the deposit inhibit magnetite dissolution

Characterization of thin TiO2 films prepared by plasma enhanced chemical vapour deposition for optical and photocatalytic applications

International Nuclear Information System (INIS)

Sobczyk-Guzenda, A.; Gazicki-Lipman, M.; Szymanowski, H.; Kowalski, J.; Wojciechowski, P.; Halamus, T.; Tracz, A.

2009-01-01

Thin titanium oxide films were deposited using a radio frequency (RF) plasma enhanced chemical vapour deposition method. Their optical properties and thickness were determined by means of ultraviolet-visible absorption spectrophotometry. Films of the optical parameters very close to those of titanium dioxide have been obtained at the high RF power input. Their optical quality is high enough to allow for their use in a construction of stack interference optical filters. At the same time, these materials exhibit strong photocatalytic effects. The results of structural analysis, carried out by Raman Shift Spectroscopy, show that the coatings posses amorphous structure. However, Raman spectra of the same films subjected to thermal annealing at 450 o C disclose an appearance of a crystalline form, namely that of anatase. Surface morphology of the films has also been characterized by Atomic Force Microscopy revealing granular, broccoli-like topography of the films.

Diagenetic controls on porosity variations within an aeolian sandstone reservoir, borehole Kudu 9A-3

International Nuclear Information System (INIS)

Marot, J.E.B.

1990-01-01

Three boreholes, Kudu 9A-1, 9A-2 and 9A-3, were drilled approximately 125 km west of the Orange River mouth to test a gas-bearing structure of Barremian age. The reservoir interval comprises an upper unit of interbedded shallow marine sandstones, limestones and volcaniclastic mass flow deposits, and a lower non-marine unit of interbedded aeolian sandstones, basaltic lavas and volcaniclastic deposits. Despite the overall good poroperm characteristics of the aeolian sandstone and its apparent mineralogical homogeneity, as implied by a gamma ray trace, the core analysis results show an extreme variation in porosity and permeability values. In order to assist in reservoir quality prediction and to assess the regional prospectivity of the sandstone, it was necessary to explain these variations. The resuls of the study indicate that compositionally and texturally the sandstones are extremely homogeneous. It is concluded that the marked variation in the poroperm characteristics of the aeolian sandstones is a result of a relatively complex diagenesis. A fluctuating water table resulted in the formation of a pattern of calcite, anhydrite and quartz cements within an aeolian dune sandstone. 7 refs., 1 fig

Deposition and characterization of Pt nanocluster films by means of gas aggregation cluster source

Energy Technology Data Exchange (ETDEWEB)

Kylián, Ondřej, E-mail: ondrej.kylian@gmail.com; Prokeš, Jan; Polonskyi, Oleksandr; Čechvala, Juraj; Kousal, Jaroslav; Pešička, Josef; Hanuš, Jan; Biederman, Hynek

2014-11-28

In this study we report on the deposition of Pt nanocluster films prepared by gas aggregation source that was operated with argon as working gas. The aim of this study was optimization of deposition process as well as determination of properties of deposited nanocluster films and their temporal stability. It was found that the production of Pt nanoclusters reached maximum value for pressure of 100 Pa and increases monotonously with magnetron current. The deposition rate at optimized deposition conditions was 0.7 nm of the Pt nanocluster film per second. Deposited films were porous and composed of 4 nm Pt nanoclusters. The nanoclusters were metallic and no sights of their oxidation were observed after 1 year on open air as witnessed by X-ray photoelectron spectroscopy. Regarding the electrical properties, a dramatic decrease of the resistivity was observed with increasing amount of deposited nanoclusters. This decrease saturated for the films approximately 50 nm thick. Such behavior indicates transition between different mechanisms of electrical conductivity: charge hopping for thin discontinuous films and current conduction through conducting path formed when higher amount of nanoclusters is deposited. Different mechanisms of electrical conduction for thin and thick layers of Pt were confirmed by subsequent investigation of temperature dependence of resistivity. In addition, no changes in resistivity were observed after one year on open air that confirms stability of produced Pt nanocluster films. - Highlights: • Pt nanocluster films were deposited by gas aggregation nanocluster source. • Conditions leading to effective deposition of Pt nanocluster films were found. • Deposited nanocluster films have good temporal stability. • Electrical properties of Pt films were found to depend on their thickness.

Characterization and Analysis of Ultrathin CIGS Films and Solar Cells Deposited by 3-Stage Process

Directory of Open Access Journals (Sweden)

Grace Rajan

2018-01-01

Full Text Available In view of the large-scale utilization of Cu(In,GaSe2 (CIGS solar cells for photovoltaic application, it is of interest not only to enhance the conversion efficiency but also to reduce the thickness of the CIGS absorber layer in order to reduce the cost and improve the solar cell manufacturing throughput. In situ and real-time spectroscopic ellipsometry (RTSE has been used conjointly with ex situ characterizations to understand the properties of ultrathin CIGS films. This enables monitoring the growth process, analyzing the optical properties of the CIGS films during deposition, and extracting composition, film thickness, grain size, and surface roughness which can be corroborated with ex situ measurements. The fabricated devices were characterized using current voltage and quantum efficiency measurements and modeled using a 1-dimensional solar cell device simulator. An analysis of the diode parameters indicates that the efficiency of the thinnest cells was restricted not only by limited light absorption, as expected, but also by a low fill factor and open-circuit voltage, explained by an increased series resistance, reverse saturation current, and diode quality factor, associated with an increased trap density.

Mechanical properties of simulated Mars materials: gypsum-rich sandstones and lapilli tuff

Science.gov (United States)

Morrow, Carolyn; Lockner, David; Okubo, Chris

2013-01-01

Observations by the Mars Exploration Rover (MER) Opportunity, and other recent studies on diagenesis in the extensive equatorial layered deposits on Mars, suggest that the likely lithologies of these deposits are gypsum-rich sandstones and tuffaceous sediments (for example, Murchie and others, 2009; Squyres and others, 2012; Zimbelman and Scheidt, 2012). Of particular interest is how the diagenesis history of these sediments (degree of cementation and composition) influences the strength and brittle behavior of the material. For instance, fractures are more common in lower porosity materials under strain, whereas deformation bands, characterized by distributed strain throughout a broader discontinuity in a material, are common in higher porosity sedimentary materials. Such discontinuities can either enhance or restrict fluid flow; hence, failure mode plays an important role in determining the mechanics of fluid migration through sediments (Antonellini and Aydin, 1994; 1995; Taylor and Pollard, 2000; Ogilvie and Glover, 2001). As part of a larger study to characterize processes of fault-controlled fluid flow in volcaniclastic and gypsum-rich sediments on Mars, we have completed a series of laboratory experiments to focus on how gypsum clast content and degree of authigenic cementation affects the strength behavior of simulated Mars rocks. Both axial deformation and hydrostatic pressure tests were done at room temperature under dry conditions.

Hereditary iron and copper deposition

DEFF Research Database (Denmark)

Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

2007-01-01

Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about......, they may be inadequate in patients diagnosed so late that extensive body deposits of metal have been developed. The main research needs in this field are to further clarify molecular mechanisms of disease progression and to develop new chelators that are more effective and less toxic than those presently...

Temporal constraints on the tectonic evolution of Sierra De Famatina, northwestern Argentina, using the fission-track method to date tuffs interbedded in synorogenic clastic sedimentary strata

Energy Technology Data Exchange (ETDEWEB)

Tabbutt, K.D. (Dartmouth College, Hanover, NH (USA))

1990-07-01

Fission-track dates from seven volcaniclastic units allow time constraints to be placed on synorogenic clastic strata exposed along the flanks of Sierra de Famatina, northwest Argentina. Four formations are exposed along the western margin of Sierra de Famatina. The El Abra conglomerate is composed of clasts eroded from the basement exposed just to the west of Cadena de Paiman. The El Buey Formation contains sediments probably derived from the Precordillera fold and thrust belt to the west. Fission-track dates give a maximum age of 6 Ma for the deposition of both of these formations. The El Durazno Formation, deposited between 6 and 4 Ma, contains proximal volcaniclastic and other clastic rocks derived from the core of Sierra de Famatina. The Santa Florentina conglomerate was derived from the rising Sierra de Famatina and deposited in the past 4 m.y. Sierra de Famatima probably became a positive topographic feature approximately 6 Ma. Prior to that time this region was receiving fine-grained sediments from a distal fold and thrust belt and conglomerates from local basement uplifts. Minor extrusive events (Mogote Formation) coincide both spatially and temporally with deformation along the major reverse faults that control the uplift of Sierra de Famatina. Minimum mean uplift rates calculated for Sierra de Famatina are 0.8 {plus minus} 0.1 mm/yr over a 6.8 m.y. interval.

Investigation of growth and characterization of nanostructured CuIn5S8 thin films produced by glancing angle deposition

International Nuclear Information System (INIS)

Sinaoui, A.; Chaffar-Akkari, F.; Gallas, B.; Demaille, D.; Kanzari, M.

2015-01-01

Ternary chalcogenide of copper and indium (CuIn 5 S 8 ) thin films were grown by thermal evaporation method using GLancing Angle Deposition (GLAD) technique. The samples were prepared under different incident angles (α = 0°, 40°, 60° and 85° measured from the normal to the substrate surface) with a substrate rotation of 2 rpm. X-ray diffraction, scanning electron microscopy, and ultraviolet–visible-infrared spectra are employed to characterize the microstructure and optical properties of the CuIn 5 S 8 thin films deposited by this technique. Under the GLAD conditions, we demonstrate that with substrate rotation, the columns were grown vertically due to the shadowing symmetry. The optical constants of the deposited films were determined from the analysis of transmission and reflection data. The results show that the refractive index and the thickness were decreased as α rises from 0° to 85° while the porosity and the Urbach energy were increased with increasing of the incident angle. The minimum refractive index is found to be 2.03 for the helical CuIn 5 S 8 film deposited at an angle of 85° and the Urbach energy was found to increase from 0.29 to 0.5 eV as α rises from 0° to 85°. Such changes of the optical behaviors are correlated with changes of the microstructure, especially a porous architecture which is favored for high incident angle. These properties exhibit potential for use in applications such as photonic crystals, graded index optical filters, and birefrigent omnidirectional reflectors. - Highlights: • GLancing angle deposition technique was employed to prepare CuIn 5 S 8 thin films. • CuIn 5 S 8 films exhibit a spinel structure with a preferred orientation along 311. • With substrate rotation, the columns were grown vertically due to shadowing symmetry. • The refractive index decreases with increasing glancing angle deposition. • Variations of the optical behaviors were correlated to the highly porous structure

Characterization of laser metal deposited 316L stainless steel

CSIR Research Space (South Africa)

Bayode, A

2016-06-01

Full Text Available investigates the effects of laser power on the structural integrity, microstructure and microhardness of laser deposited 316L stainless steel. The result showed that the laser power has much influence on the evolving microstructure and microhardness...

Thermal Vapor Deposition and Characterization of Polymer-Ceramic Nanoparticle Thin Films and Capacitors

Science.gov (United States)

Iwagoshi, Joel A.

Research on alternative energies has become an area of increased interest due to economic and environmental concerns. Green energy sources, such as ocean, wind, and solar power, are subject to predictable and unpredictable generation intermittencies which cause instability in the electrical grid. This problem could be solved through the use of short term energy storage devices. Capacitors made from composite polymer:nanoparticle thin films have been shown to be an economically viable option. Through thermal vapor deposition, we fabricated dielectric thin films composed of the polymer polyvinylidine fluoride (PVDF) and the ceramic nanoparticle titanium dioxide (TiO2). Fully understanding the deposition process required an investigation of electrode and dielectric film deposition. Film composition can be controlled by the mass ratio of PVDF:TiO2 prior to deposition. An analysis of the relationship between the ratio of PVDF:TiO2 before and after deposition will improve our understanding of this novel deposition method. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy were used to analyze film atomic concentrations. The results indicate a broad distribution of deposited TiO2 concentrations with the highest deposited amount at an initial mass concentration of 17% TiO2. The nanoparticle dispersion throughout the film is analyzed through atomic force microscopy and energy dispersive x-ray spectroscopy. Images from these two techniques confirm uniform TiO2 dispersion with cluster size less than 300 nm. These results, combined with spectroscopic analysis, verify control over the deposition process. Capacitors were fabricated using gold parallel plates with PVDF:TiO 2 dielectrics. These capacitors were analyzed using the atomic force microscope and a capacohmeter. Atomic force microscope images confirm that our gold films are acceptably smooth. Preliminary capacohmeter measurements indicate capacitance values of 6 nF and break down voltages of 2.4 V

Mineralogy and geochemistry of two metamorphosed sedimentary manganese deposits, Sierra Nevada, California, USA

Science.gov (United States)

Flohr, M.J.K.; Huebner, J.S.

1992-01-01

Laminated to massive rhodochrosite, hausmannite, and Mn-silicates from the Smith prospect and Manga-Chrome mine, Sierra Nevada, California were deposited as ocean floor sediments associated with chert and shale. The principal lithologies at Smith are chert, argillite, rhodochrosite-, hausmannite- and chlorite-rich layers, and relatively uncommon layers of jacobsite. The Manga-Chrome mine also contains layers rich in manganoan calcite and caryopilite. Tephroite, rhodonite, spessartine, and accessory alleghanyite and sonolite formed during metamorphism. Volcaniclastic components are present at Manga-Chrome as metavolcanic clasts and as Mn-poor, red, garnet- and hematite-rich layers. There is no evidence, such as relict lithologies, that Mn was introduced into Mn-poor lithologies such as chert, limestone or mudstone. Replacement of Mn-poor phases by Mn-rich phases is observed only in the groundmass of volcanic clasts that appear to have fallen into soft Mn-rich mud. Manganiferous samples from the Smith prospect and Manga-Chrome mine have high Mn Fe and low concentrations of Ni, Cu, Zn, Co, U, Th and the rare-earth elements that are similar to concentrations reported from other ancient Mn deposits found in chert-greenstone complexes and from manganiferous sediments and crusts that are forming near modern sea floor vents. The Sierra Nevada deposits formed as precipitates of Mn-rich sediments on the sea floor, probably from mixtures of circulating hydrothermal fluids and seawater. The composition of a metabasalt from the Smith prospect is consistent with those of island-arc tholeiites. Metavolcanic clasts from the Manga-Chrome mine are compositionally distinct from the Smith metabasalt and have alkaline to calc-alkaline affinities. A back-arc basin is considered to be the most likely paleoenvironment for the formation of the Mn-rich lenses at the Manga-Chrome mine and, by association, the Smith prospect. Layers of rhodochrosite, hausmannite and chert preserve the

AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

Energy Technology Data Exchange (ETDEWEB)

Andrade, Jose Elisandro de; Machado, Rogerio; Macedo, Marcelo Andrade; Cunha, Frederico Guilherme Carvalho [Clinica de Medicina Nuclear e Radiologia de Maceio (MedRadiUS), Radiology and Imaging Diagnosis at Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil)

2012-07-01

In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 deg C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin film were analyzed by Atomic Force Microscopy (AFM) in the non-contact mode. Silver thin films were also analyzed using X-ray diffraction (XRD) at room temperature. The AFM results showed the formation of silver crystallites on the surface of DGEBA at very low coverage whereas XRD indicated that most of them had their main axis aligned to the normal of the surface. An increase in the coverage led to an increase in the grain size as indicated by AFM. However, XRD results indicated that the crystallite size remained almost constant while the appearance of peaks corresponding to other crystalline orientations suggests the coalescence of the original crystallites and an increase in size of the more dense planes, namely [111]. (author)

AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

Energy Technology Data Exchange (ETDEWEB)

Andrade, Jose Elisandro de; Machado, Rogerio; Macedo, Marcelo Andrade [Universidade Federal de Sergipe (UFSE), Aracaju, SE (Brazil). Programa de Pos-graduacao em Fisica; Cunha, Frederico Guilherme Carvalho [Universidade Federal de Sergipe (UFSE), Aracaju, SE (Brazil). Programa de Pos-graduacao em Ciencia e Engenharia de Materiais

2012-07-01

In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 Degree-Sign C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin film were analyzed by Atomic Force Microscopy (AFM) in the non-contact mode. Silver thin films were also analyzed using X-ray diffraction (XRD) at room temperature. The AFM results showed the formation of silver crystallites on the surface of DGEBA at very low coverage whereas XRD indicated that most of them had their main axis aligned to the normal of the surface. An increase in the coverage led to an increase in the grain size as indicated by AFM. However, XRD results indicated that the crystallite size remained almost constant while the appearance of peaks corresponding to other crystalline orientations suggests the coalescence of the original crystallites and an increase in size of the more dense planes, namely [111]. (author)

Electrochemical Characterization of Nanoporous Nickel Oxide Thin Films Spray-Deposited onto Indium-Doped Tin Oxide for Solar Conversion Scopes

Directory of Open Access Journals (Sweden)

Muhammad Awais

2015-01-01

Full Text Available Nonstoichiometric nickel oxide (NiOx has been deposited as thin film utilizing indium-doped tin oxide as transparent and electrically conductive substrate. Spray deposition of a suspension of NiOx nanoparticles in alcoholic medium allowed the preparation of uniform NiOx coatings. Sintering of the coatings was conducted at temperatures below 500°C for few minutes. This scalable procedure allowed the attainment of NiOx films with mesoporous morphology and reticulated structure. The electrochemical characterization showed that NiOx electrodes possess large surface area (about 1000 times larger than their geometrical area. Due to the openness of the NiOx morphology, the underlying conductive substrate can be contacted by the electrolyte and undergo redox processes within the potential range in which NiOx is electroactive. This requires careful control of the conditions of polarization in order to prevent the simultaneous occurrence of reduction/oxidation processes in both components of the multilayered electrode. The combination of the open structure with optical transparency and elevated electroactivity in organic electrolytes motivated us to analyze the potential of the spray-deposited NiOx films as semiconducting cathodes of dye-sensitized solar cells of p-type when erythrosine B was the sensitizer.

AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

Directory of Open Access Journals (Sweden)

José Elisandro de Andrade

2013-01-01

Full Text Available In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA epoxy resin cured at 150 °C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin film were analyzed by Atomic Force Microscopy (AFM in the non-contact mode. Silver thin films were also analyzed using X-ray diffraction (XRD at room temperature. The AFM results showed the formation of silver crystallites on the surface of DGEBA at very low coverage whereas XRD indicated that most of them had their main axis aligned to the normal of the surface. An increase in the coverage led to an increase in the grain size as indicated by AFM. However, XRD results indicated that the crystallite size remained almost constant while the appearance of peaks corresponding to other crystalline orientations suggests the coalescence of the original crystallites and an increase in size of the more dense planes, namely [111].

Characterization of Pd catalyst-electrodes deposited on YSZ: Influence of the preparation technique and the presence of a ceria interlayer

Energy Technology Data Exchange (ETDEWEB)

Jimenez-Borja, Carmen, E-mail: Carmen.JBorja@uclm.es [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad de Castilla-La Mancha. Avenida Camilo Jose Cela 12, 13071 Ciudad Real (Spain); Matei, Florina [Department of Petroleum Processing Engineering and Environmental Protection, Petroleum - Gas University of Ploiesti (Romania); Dorado, Fernando; Valverde, Jose Luis [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad de Castilla-La Mancha. Avenida Camilo Jose Cela 12, 13071 Ciudad Real (Spain)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Impregnation of palladium over YSZ led to more dispersed films. Black-Right-Pointing-Pointer XPS spectra indicated electron deficient Pd{sup 2+} species on the surface of palladium films. Black-Right-Pointing-Pointer Impregnated palladium films were more active than those prepared by paste deposition Black-Right-Pointing-Pointer The addition of a CeO{sub 2} interlayer enhanced the catalytic rate for the impregnated samples. - Abstract: Palladium catalyst-electrodes supported on Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) prepared either by paste deposition or wet impregnation technique were characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found a strong dependence of the catalytic film preparation technique as well as of the presence of a ceria interlayer between the palladium film and the solid electrolyte on the catalytic activity towards methane oxidation. Impregnated palladium films were found to be more active than films prepared by paste deposition. Besides, the addition of ceria allowed stabilizing the palladium active phase for methane oxidation.

Characterization of in-swath spray deposition for CP-11TT flat-fan nozzles used in low volume aerial application of crop production and protection materials

Science.gov (United States)

For aerial application of crop production and protection materials, a complex interaction of controllable and uncontrollable factors is involved. It is difficult to completely characterize spray drift and deposition, but estimates can be made with appropriate sampling protocol and analysis. With c...

Deposition and characterization of sputtered hexaboride coatings

International Nuclear Information System (INIS)

Waldhauser, W.

1996-06-01

Hexaborides of the rare-earth elements ReB 6 are potential materials for cathode applications since they combine properties such as low work function, good electrical conductivity, high melting point as well as low volatility at high temperatures. Due to their high hardness and colorations ranging from blue to purple these compounds are also considered for applications to coatings for decoration of consumer products. At present, either rods of sintered LaB 6 or single LaB 6 crystals are indirectly heated to induce emission. In this workboride coatings were deposited onto various substrates employing non-reactive magnetron sputtering from LaB 6 , CeB 6 , SmB 6 and YB 6 targets. Coatings deposited were examined using scanning electron microscopy, X-ray diffraction, electron probe microanalysis. Vickers microhardness, colorimeter and spectroscopic ellipsometry measurements. Electron emission characteristics of the coatings were studied by the thermionic emission and the contact potential method. After optimization of the sputtering parameters fine-columnar or partially amorphous films with atomic ratios of boron to metal in the order of 5 to 7.5 were obtained. The tendency to form the corresponding hexaboride phase decreases from LaB 6 , CeB 6 and SmB 6 to YB 6 . The work function was measured to be in the range of 2.6 to 3.3 eV. Vickers microhardness values lie between 1500 and 2000 HVO.01. LaB 6 coatings showed the most pronounced visual color impression corresponding to dark violet. The results obtained indicate that sputtered hexaboride films are well suited for decorative and thermionic applications. (author)

Characterization of thin film deposits on tungsten filaments in catalytic chemical vapor deposition using 1,1-dimethylsilacyclobutane

Energy Technology Data Exchange (ETDEWEB)

Shi, Yujun, E-mail: shiy@ucalgary.ca; Tong, Ling; Mulmi, Suresh [Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

2016-09-15

Metal filament plays a key role in the technique of catalytic chemical vapor deposition (Cat-CVD) as it serves as a catalyst in dissociating the source gas to form reactive species. These reactive species initiate the gas-phase reaction chemistry and final thin film and nanostructure formation. At the same time, they also react with the metal itself, leading to the formation of metal alloys and other deposits. The deposits on the tungsten filaments when exposed to 1,1-dimethylsilacyclobutane (DMSCB), a single-source precursor for silicon carbide thin films, in the process of Cat-CVD were studied in this work. It has been demonstrated that a rich variety of deposits, including tungsten carbides (W{sub 2}C and WC), tungsten silicide (W{sub 5}Si{sub 3}), silicon carbide, amorphous carbon, and graphite, form on the W filament surfaces. The structural and morphological changes in the tungsten filaments depend strongly on the DMSCB pressure and filament temperature. At 1000 and 2000 °C, the formation of WC and W{sub 2}C dominates. In addition, a thin amorphous carbon layer has been found at 1500 °C with the 0.12 and 0.24 Torr of DMSCB and a lower temperature of 1200 °C with the 0.48 Torr of DMSCB. An increase in the DMSCB sample pressure gives rise to higher Si and C contents. As a result, the formation of SiC and W{sub 5}Si{sub 3} has been observed with the two high-pressure DMSCB samples (i.e., 0.24 and 0.48 Torr). The rich decomposition chemistry of DMSCB on the W surfaces is responsible for the extensive changes in the structure of the W filament, providing support for the close relationship between the gas-phase decomposition chemistry and the nature of alloy formation on the metal surface. The understanding of the structural changes obtained from this work will help guide the development of efficient methods to solve the filament aging problem in Cat-CVD and also to achieve a controllable deposition process.

Improvements to the characterization of organic nitrogen chemistry and deposition in CMAQ (CMAS Presentation)

Science.gov (United States)

Excess atmospheric nitrogen deposition can cause significant harmful effects to ecosystems. Organic nitrogen deposition can be an important contributor to the total nitrogen budget, contributing 10-30%, however there are large uncertainties in the chemistry and deposition of thes...

Characterization of chemical vapour deposited diamond films: correlation between hydrogen incorporation and film morphology and quality

International Nuclear Information System (INIS)

Tang, C J; Neves, A J; Carmo, M C

2005-01-01

In order to tailor diamond synthesized through chemical vapour deposition (CVD) for different applications, many diamond films of different colours and variable quality were deposited by a 5 kW microwave plasma CVD reactor under different growth conditions. The morphology, quality and hydrogen incorporation of these films were characterized using scanning electron microscopy (SEM), Raman and Fourier-transform infrared (FTIR) spectroscopy, respectively. From this study, a general trend between hydrogen incorporation and film colour, morphology and quality was found. That is, as the films sorted by colour gradually become darker, ranging from white through grey to black, high magnification SEM images illustrate that the smoothness of the well defined crystalline facet gradually decreases and second nucleation starts to appear on it, indicating gradual degradation of the crystalline quality. Correspondingly, Raman spectra evidence that the diamond Raman peak at 1332 cm -1 becomes broader and the non-diamond carbon band around 1500 cm -1 starts to appear and becomes stronger, confirming increase of the non-diamond component and decrease of the phase purity of the film, while FTIR spectra show that the CH stretching band and the two CVD diamond specific peaks around 2830 cm -1 rise rapidly, and this indicates that the total amount of hydrogen incorporated into the film increases significantly

Characterization of deep wet etching of fused silica glass for single cell and optical sensor deposition

International Nuclear Information System (INIS)

Zhu, Haixin; Holl, Mark; Ray, Tathagata; Bhushan, Shivani; Meldrum, Deirdre R

2009-01-01

The development of a high-throughput single-cell metabolic rate monitoring system relies on the use of transparent substrate material for a single cell-trapping platform. The high optical transparency, high chemical resistance, improved surface quality and compatibility with the silicon micromachining process of fused silica make it very attractive and desirable for this application. In this paper, we report the results from the development and characterization of a hydrofluoric acid (HF) based deep wet-etch process on fused silica. The pin holes and notching defects of various single-coated masking layers during the etching are characterized and the most suitable masking materials are identified for different etch depths. The dependence of the average etch rate and surface roughness on the etch depth, impurity concentration and HF composition are also examined. The resulting undercut from the deep HF etch using various masking materials is also investigated. The developed and characterized process techniques have been successfully implemented in the fabrication of micro-well arrays for single cell trapping and sensor deposition. Up to 60 µm deep micro-wells have been etched in a fused silica substrate with over 90% process yield and repeatability. To our knowledge, such etch depth has never been achieved in a fused silica substrate by using a non-diluted HF etchant and a single-coated masking layer at room temperature

Fabrication and characterization of Ni-decorated h-BN powders with ChCl-EG ionic liquid as addition by electroless deposition

Science.gov (United States)

Yang, Qionglian; Ru, Juanjian; Song, Peng; Hu, Mingyu; Feng, Jing

2018-05-01

Ni-decorated h-BN powders are fabricated with ChCl-EG as additive via electroless plating in the paper. As comparison, the different additive concentration of choline chloride-ethylene glycol (ChCl-EG) ionic liquid (0 g l-1, 30 g l-1, 60 g l-1, 90 g l-1) is presented. The effects of ChCl-EG concentration are studied, including the surface morphologies, phase analysis of Ni-decorated h-BN powders and the residual Ni2+ concentration is measured in electroless plating bath. It is demonstrated that the deposition phenomena of nickel particles on h-BN surface is changed with the addition of ChCl-EG. When the concentration of ChCl-EG is 30 g l-1, the Ni particles on h-BN surface are in dispersed and spheroid state with the average size of 10-1000 nm. It can be found that 30 g l-1 ChCl-EG is conducive to the arise of deposition phenomena, which is the formation of the single nickel particle on h-BN surface. Besides, more Ni particles are deposited on h-BN surface with the increase of nickel plating times, which is characterized with scanning electron microscope and transmission electron microscope. Furthermore, the deposition phenomenon and growth mechanism are proposed without and with ChCl-EG as additive to further elaborate the formation of Ni particles on h-BN surface.

Fabrication and characterization of Ni-decorated h-BN powders with ChCl-EG ionic liquid as addition by electroless deposition.

Science.gov (United States)

Yang, Qionglian; Ru, Juanjian; Song, Peng; Hu, Mingyu; Feng, Jing

2018-05-01

Ni-decorated h-BN powders are fabricated with ChCl-EG as additive via electroless plating in the paper. As comparison, the different additive concentration of choline chloride-ethylene glycol (ChCl-EG) ionic liquid (0 g l -1 , 30 g l -1 , 60 g l -1 , 90 g l -1 ) is presented. The effects of ChCl-EG concentration are studied, including the surface morphologies, phase analysis of Ni-decorated h-BN powders and the residual Ni 2+ concentration is measured in electroless plating bath. It is demonstrated that the deposition phenomena of nickel particles on h-BN surface is changed with the addition of ChCl-EG. When the concentration of ChCl-EG is 30 g l -1 , the Ni particles on h-BN surface are in dispersed and spheroid state with the average size of 10-1000 nm. It can be found that 30 g l -1 ChCl-EG is conducive to the arise of deposition phenomena, which is the formation of the single nickel particle on h-BN surface. Besides, more Ni particles are deposited on h-BN surface with the increase of nickel plating times, which is characterized with scanning electron microscope and transmission electron microscope. Furthermore, the deposition phenomenon and growth mechanism are proposed without and with ChCl-EG as additive to further elaborate the formation of Ni particles on h-BN surface.

Reconstruction of the Paleoproterozoic deeper ocean environment: Preliminary Report of the Ghana Birimian Greenstone Belt Drilling Project (GHB)

Science.gov (United States)

Kiyokawa, S.; Yoshimaru, S.; Miki, T.; Sakai, S.; Ikehara, M.; Yamaguchi, K. E.; Ito, T.; Onoue, T.; Takehara, M.; Tetteh, G. M.; Nyame, F. K.

2016-12-01

The Paleoproterozoic Era are one of the most rapid environmental change when the earth surface environment was affected by formation of continents and increasing atmospheric oxygen levels. Major oxidation of Great Oxidation Event (GOE) are reported this ages (eg. Holland, 2006; Condie, 2001; Lyons et al., 2014). The nature of deep sea environments at this time have not been clearly identified and oceanic sediments are mostly involved in subduction. The Paleoproterozoic Birimian Greenstone Belt is an ophiolitic volcaniclastic sequence in Ghana, with depositional age of over 2.3-2.2 Ga (Petersson et al., 2016). Detail research was conducted of the Ashanti (Axim-Konongo) Belt of the Birimian Greenstone Belt along the coast near Cape Three Points area. Very thick volcaniclastic and organic-rich sedimentary rocks, which we now refer to as the Cape Three Points Group, crop out in the lower part of the Birimian Greenstone Belt. Stratigraphically, three unit identified; the lower portion contains thick vesicular volcaniclastic rocks, the middle portion is made up of laminated volcaniclastics and black shale, and the upper portion dominated by fine laminated volcaniclastics with more black shale sequence. Continuous core drilling from Dec 3-12th 2015 of the upper part of the sequence intersected saprolite to a depth of 30m and fresh, well preserved stratigraphy with graded bedding and lamination to a depth of 195m. Half cut cores show well laminated organic rich black shale and relative carbonate rich layers with very fine pyrite grains. SHRIMP age data from a porphyry intrusion into this sequence indicate an age of 2250 Ma. Carbon isotope analysis shows δ13C = -43 to -37‰ for black shale with the very light isotope values for cyanobacterial signature.The fining-upward sequences, well laminated bed and black shales and REE data suggest this sequence situated partly silent stagnant with volcanic activity ocean floor environment around an oceanic island arc condition.

Nano-Impact (Fatigue Characterization of As-Deposited Amorphous Nitinol Thin Film

Directory of Open Access Journals (Sweden)

Rehan Ahmed

2012-08-01

Full Text Available This paper presents nano-impact (low cycle fatigue behavior of as-deposited amorphous nitinol (TiNi thin film deposited on Si wafer. The nitinol film was 3.5 µm thick and was deposited by the sputtering process. Nano-impact tests were conducted to comprehend the localized fatigue performance and failure modes of thin film using a calibrated nano-indenter NanoTest™, equipped with standard diamond Berkovich and conical indenter in the load range of 0.5 mN to 100 mN. Each nano-impact test was conducted for a total of 1000 fatigue cycles. Depth sensing approach was adapted to understand the mechanisms of film failure. Based on the depth-time data and surface observations of films using atomic force microscope, it is concluded that the shape of the indenter test probe is critical in inducing the localized indentation stress and film failure. The measurement technique proposed in this paper can be used to optimize the design of nitinol thin films.

Influence of deposition rate on the properties of tin coatings deposited on tool steels using arc method

International Nuclear Information System (INIS)

Akhtar, P.; Abbas, M.

2007-01-01

Titanium nitride (TiN) widely used as hard coating material, was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapour deposition method. The study concentrated on cathodic arc physical vapour deposition (CAPVD), a technique used for the deposition of hard coatings for tooling applications, and which has many advantages. The main drawback of this technique, however, is the formation of macrodroplets (MD's) during deposition, resulting in films with rougher morphology. Various standard characterization techniques and equipment, such as electron microscopy, atomic force microscopy, hardness testing machine, scratch tester and pin-on-disc machine, were used to analyze and quantify the following properties and parameters, surface morphology, thickness, hardness, adhesion and coefficient of friction (COF) of the deposited coatings. Surface morphology revealed that the MD's produced during the etching stage, protruded through the thin film, resulting in film with deteriorated surface features. Both coating thickness and indentation loads influenced the hardness of the deposited coatings. The coatings deposited on HSS exhibit better adhesion compared to those on D2 tool steel. Standard deviation indicates that the coating deposited with thickness around 6.7 macro m showed the most stable trend of COF versus sliding distance. (author)

A case of regression of atypical dense deposit disease without C3 deposition in a child.

Science.gov (United States)

Kim, Min Sun; Hwang, Pyoung Han; Kang, Mung Jae; Lee, Dae-Yeol

2010-07-01

Dense deposit disease (DDD) is a rare disorder characterized by the deposition of abnormal electron-dense material within the glomerular basement membrane of the kidneys. The diagnosis is made in most patients between 5 and 15 years of age, and within 10 years, approximately half of the affected patients progress to end-stage renal disease. We report a rare case of regressive DDD without C3 deposition after steroid therapy in an 11-year-old boy. The patient presented with edema, gross hematuria, and nephrotic-range proteinuria. Laboratory testing revealed a serum creatinine level of 1.17 mg/dL, albumin level of 2.3 g/dL, and serum C3 level of 125 mg/dL (range 90-180 mg/dL). The results of the renal biopsy were consistent with DDD without C3 deposition. After 6 weeks of steroid therapy, the nephrotic syndrome completely resolved. The follow-up renal biopsy showed a significant reduction in mesangial proliferation and disappearance of electron-dense deposits in the GBM.

Microstructural and optical properties of nanocrystalline ZnO deposited onto vertically aligned carbon nanotubes by physical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Borkar, Tushar [Department of Materials Science and Engineering and Center for Advanced Research and Technology, University of North Texas, Denton 76203 (United States); Chang, Won Seok [Korea Institute of Machinery and Materials, 104 Sinseongno, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Hwang, Jun Yeon, E-mail: Junyeon.Hwang@kist.re.kr [Department of Materials Science and Engineering and Center for Advanced Research and Technology, University of North Texas, Denton 76203 (United States); Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-902 (Korea, Republic of); Shepherd, Nigel D.; Banerjee, Rajarshi [Department of Materials Science and Engineering and Center for Advanced Research and Technology, University of North Texas, Denton 76203 (United States)

2012-10-15

Nanocrystalline ZnO films with thicknesses of 5 nm, 10 nm, 20 nm, and 50 nm were deposited via magnetron sputtering onto the surface of vertically aligned multi-walled carbon nanotubes (MWCNTs). The ZnO/CNTs heterostructures were characterized by scanning electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction studies. No structural degradation of the CNTs was observed and photoluminescence (PL) measurements of the nanostructured ZnO layers show that the optical properties of these films are typical of ZnO deposited at low temperatures. The results indicate that magnetron sputtering is a viable technique for growing heterostructures and depositing functional layers onto CNTs.

Principal types of precambrian uranium-gold deposits and their metallogenetic characteristics in China

International Nuclear Information System (INIS)

Liang Liang; Zhong Zhiyun.

1988-01-01

Principal types of Precambrian uranium-gold deposits are follows: paleo-conglomerate uranium-deposit, stratified or strata-bound uranium-gold deposit, unconformity-related uranium deposit (no or seldem gold) and greenstone gold deposit. The main types of gold deposits in China is greenstone one which is characterized by later age, high grade metamorphism and a large time difference between diagenesis of host rocks and gold metallogenesis. Gold deposits are spatially distributed in the uplift area, whereas uranium deposits are distributed in the downfaulted belt. Furthermore, both uranium and gold deposits are controlled by regional fractures

Microstructural, chemical and textural characterization of ZnO nanorods synthesized by aerosol assisted chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Sáenz-Trevizo, A.; Amézaga-Madrid, P.; Fuentes-Cobas, L.; Pizá-Ruiz, P.; Antúnez-Flores, W.; Ornelas-Gutiérrez, C. [Centro de Investigación en Materiales Avanzados, S.C., Chihuahua, Chihuahua 31109 (Mexico); Pérez-García, S.A. [Centro de Investigación en Materiales Avanzados, S.C., Unidad Monterrey, Apodaca, Nuevo León 66600 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C., Chihuahua, Chihuahua 31109 (Mexico)

2014-12-15

ZnO nanorods were synthesized by aerosol assisted chemical vapor deposition onto TiO{sub 2} covered borosilicate glass substrates. Deposition parameters were optimized and kept constant. Solely the effect of different nozzle velocities on the growth of ZnO nanorods was evaluated in order to develop a dense and uniform structure. The crystalline structure was characterized by conventional X-ray diffraction in grazing incidence and Bragg–Brentano configurations. In addition, two-dimensional grazing incidence synchrotron radiation diffraction was employed to determine the preferred growth direction of the nanorods. Morphology and growth characteristics analyzed by electron microscopy were correlated with diffraction outcomes. Chemical composition was established by X-ray photoelectron spectroscopy. X-ray diffraction results and X-ray photoelectron spectroscopy showed the presence of wurtzite ZnO and anatase TiO{sub 2} phases. Morphological changes noticed when the deposition velocity was lowered to the minimum, indicated the formation of relatively vertically oriented nanorods evenly distributed onto the TiO{sub 2} buffer film. By coupling two-dimensional X-ray diffraction and computational modeling with ANAELU it was proved that a successful texture determination was achieved and confirmed by scanning electron microscopy analysis. Texture analysis led to the conclusion of a preferred growth direction in [001] having a distribution width Ω = 20° ± 2°. - Highlights: • Uniform and pure single-crystal ZnO nanorods were obtained by AACVD technique. • Longitudinal and transversal axis parallel to the [001] and [110] directions, respectively. • Texture was determined by 2D synchrotron diffraction and electron microscopy analysis. • Nanorods have its [001] direction distributed close to the normal of the substrate. • Angular spread about the preferred orientation is 20° ± 2°.

Characterization of amorphous yttria layers deposited by aqueous solutions of Y-chelate alkoxides complex

Energy Technology Data Exchange (ETDEWEB)

Kim, Young-Soon, E-mail: kyscjb@i-sunam.com; Lee, Yu-Ri; Kim, Byeong-Joo; Lee, Jae-Hun; Moon, Seung-Hyun; Lee, Hunju

2015-01-15

Highlights: • Economical method for crack-free amorphous yttria layer deposition by dip coating. • Simpler process for planar yttria film as a diffusion barrier and nucleation layer. • Easy control over the film properties with better characteristics. • Easy control over the thickness of the deposited films. • A feasible process that can be easily adopted by HTSCC industries. - Abstract: Crack-free amorphous yttria layers were deposited by dip coating in solutions of different Y-chelate alkoxides complex. Three Y-chelate solutions of different concentrations were prepared using yttrium acetate tetrahydrate, yttrium stearic acid as Y source materials. PEG, diethanolamine were used as chelating agents, while ethanol, methanol and tetradecane were used as solvent. Three different combinations of chelating and solvents were used to prepare solutions for Y{sub 2}O{sub 3} dip coating on SUS, electropolished and non-electropolished Hastelloy C-276 substrates. The thickness of the films was varied by changing the number of dipping cycles. At an optimized condition, the substrate surface roughness (rms) value was reduced from ∼50 nm to ∼1 nm over a 10 × 10 μm{sup 2} area. After Y{sub 2}O{sub 3} deposition, MgO was deposited using ion-beam assisted deposition (IBAD), then LaMnO{sub 3} (LMO) was deposited using sputtering and GdBCO was deposited using reactive co-evaporation by deposition and reaction (RCE-DR). Detailed X-ray study indicates that LMO/MgO/Y{sub 2}O{sub 3} and GdBCO/LMO/MgO/Y{sub 2}O{sub 3} stack films have good out-of-plane and in-plane textures with strong c-axis alignment. The critical current (Ic) of GdBCO/LMO/MgO/Y{sub 2}O{sub 3} multilayer structure varied from 190 to 420 A/cm with different solutions, when measured at 77 K. These results demonstrated that amorphous yttria can be easily deposited by dip coating using Y-chelates complex as a diffusion barrier and nucleation layer.

Laser ablation and deposition of wide bandgap semiconductors: plasma and nanostructure of deposits diagnosis

Science.gov (United States)

Sanz, M.; López-Arias, M.; Rebollar, E.; de Nalda, R.; Castillejo, M.

2011-12-01

Nanostructured CdS and ZnS films on Si (100) substrates were obtained by nanosecond pulsed laser deposition at the wavelengths of 266 and 532 nm. The effect of laser irradiation wavelength on the surface structure and crystallinity of deposits was characterized, together with the composition, expansion dynamics and thermodynamic parameters of the ablation plume. Deposits were analyzed by environmental scanning electron microscopy, atomic force microscopy and X-ray diffraction, while in situ monitoring of the plume was carried out with spectral, temporal and spatial resolution by optical emission spectroscopy. The deposits consist of 25-50 nm nanoparticle assembled films but ablation in the visible results in larger aggregates (150 nm) over imposed on the film surface. The aggregate free films grown at 266 nm on heated substrates are thicker than those grown at room temperature and in the former case they reveal a crystalline structure congruent with that of the initial target material. The observed trends are discussed in reference to the light absorption step, the plasma composition and the nucleation processes occurring on the substrate.

Photoemission Spectroscopy Characterization of Attempts to Deposit MoO2 Thin Film

Directory of Open Access Journals (Sweden)

Irfan

2011-01-01

Full Text Available Attempts to deposit molybdenum dioxide (MoO2 thin films have been described. Electronic structure of films, deposited by thermal evaporation of MoO2 powder, had been investigated with ultraviolet photoemission and X-ray photoemission spectroscopy (UPS and XPS. The thermally evaporated films were found to be similar to the thermally evaporated MoO3 films at the early deposition stage. XPS analysis of MoO2 powder reveals presence of +5 and +6 oxidation states in Mo 3d core level along with +4 state. The residue of MoO2 powder indicates substantial reduction in higher oxidation states while keeping +4 oxidation state almost intact. Interface formation between chloroaluminum phthalocyanine (AlPc-Cl and the thermally evaporated film was also investigated.

Characterization and Optimization of Ni-WC Composite Weld Matrix Deposited by Plasma-Transferred Arc Process

Science.gov (United States)

Tahaei, Ali; Horley, Paul; Merlin, Mattia; Torres-Torres, David; Garagnani, Gian Luca; Praga, Rolando; Vázquez, Felipe J. García; Arizmendi-Morquecho, Ana

2017-03-01

This work is dedicated to optimization of carbide particle system in a weld bead deposited by PTAW technique over D2 tool steel with high chromium content. The paper reports partial melting of the original carbide grains of the Ni-based filling powder, and growing of the secondary carbide phase (Cr, Ni)_3W_3C in the form of dendrites with wide branches that enhanced mechanical properties of the weld. The optimization of bead parameters was made with design of experiment methodology complemented by a complex sample characterization including SEM, EDXS, XRD, and nanoindentation measurements. It was shown that the preheat of the substrate to a moderate temperature 523 K (250° C) establishes linear pattern of metal flow in the weld pool, resulting in the most homogeneous distribution of the primary carbides in the microstructure of weld bead.

Chemical characteristics of atmospheric deposition collected at two ENEA stations near Bologna

International Nuclear Information System (INIS)

Barilli, L.; Olivieri, P.; Salvi, S.; Morselli, L.; Grandi, E.; Ianuccilli, A.

1997-06-01

This article presents the results of the measurements of the water quality in acid rains, collected by a Wet and Dry Sampler in 1994 and in 1995 at two ENEA stations, Brasimone and Bologna town, belonging to the RIDEP network and characterized by different geography and different anthropogenic sources. In the Bologna station from April 95 an innovative sampler DAS (Dry Deposition on Aquatic Surface) has been activated. The monitoring has allowed determining the wet deposition fluxes in both the stations and pointing out the differences between two areas characterized by different topology. Besides the DAS sampler has allowed evaluating the total deposition fluxes (wet and dry deposition) in the Bologna station and comparing them with the ''critical loads'' pertaining to the examined territory

Deposition and Characterization of the Titanium-Based Coating by a Multi-Chamber Detonation Sprayer

Directory of Open Access Journals (Sweden)

Arseenko M.Yu.

2015-01-01

Full Text Available This work introduces some of the aspects of the deposition of titanium-based coating (80-120 μm thick on aluminium samples using a multi-chamber detonation sprayer (MCDS. The characteristic feature of MCDS is that the powder is accelerated by using combustion products that are formed in MCDS chambers and are converged before entering the nozzle, where they interact with the two-phase gas-powder cloud. The microstructures and properties of the coating were characterized with the use of scanning electronic microscopes (SEM, optical microscope (OM, X-ray Diffraction (XRD techniques, and Vickers hardness tester with a 50 g test load. Wear tests were carried out using a computer controlled pin-on-disc type tribometer. It was established that MCDS has provided the conditions for formation of a dense titanium-based coating with a porosity of less than 1.0%, microhardness 810±250 HV0.05 and a specific wear rate of 2.077∙10-4 mm3(m∙N-1.

Characterization of amorphous yttria layers deposited by aqueous solutions of Y-chelate alkoxides complex

Science.gov (United States)

Kim, Young-Soon; Lee, Yu-Ri; Kim, Byeong-Joo; Lee, Jae-Hun; Moon, Seung-Hyun; Lee, Hunju

2015-01-01

Crack-free amorphous yttria layers were deposited by dip coating in solutions of different Y-chelate alkoxides complex. Three Y-chelate solutions of different concentrations were prepared using yttrium acetate tetrahydrate, yttrium stearic acid as Y source materials. PEG, diethanolamine were used as chelating agents, while ethanol, methanol and tetradecane were used as solvent. Three different combinations of chelating and solvents were used to prepare solutions for Y2O3 dip coating on SUS, electropolished and non-electropolished Hastelloy C-276 substrates. The thickness of the films was varied by changing the number of dipping cycles. At an optimized condition, the substrate surface roughness (rms) value was reduced from ∼50 nm to ∼1 nm over a 10 × 10 μm2 area. After Y2O3 deposition, MgO was deposited using ion-beam assisted deposition (IBAD), then LaMnO3 (LMO) was deposited using sputtering and GdBCO was deposited using reactive co-evaporation by deposition and reaction (RCE-DR). Detailed X-ray study indicates that LMO/MgO/Y2O3 and GdBCO/LMO/MgO/Y2O3 stack films have good out-of-plane and in-plane textures with strong c-axis alignment. The critical current (Ic) of GdBCO/LMO/MgO/Y2O3 multilayer structure varied from 190 to 420 A/cm with different solutions, when measured at 77 K. These results demonstrated that amorphous yttria can be easily deposited by dip coating using Y-chelates complex as a diffusion barrier and nucleation layer.

Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

Directory of Open Access Journals (Sweden)

Fang Luo

2015-03-01

Full Text Available Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

Structural and optical characterization of self-assembled Ge nanocrystal layers grown by plasma-enhanced chemical vapor deposition.

Science.gov (United States)

Saeed, Saba; Buters, Frank; Dohnalova, Katerina; Wosinski, Lech; Gregorkiewicz, Tom

2014-10-10

We present a structural and optical study of solid-state dispersions of Ge nanocrystals prepared by plasma-enhanced chemical vapor deposition. Structural analysis shows the presence of nanocrystalline germanium inclusions embedded in an amorphous matrix of Si-rich SiO(2).Optical characterization reveals two prominent emission bands centered around 2.6 eV and 3.4 eV, and tunable by excitation energy. In addition, the lower energy band shows an excitation power-dependent blue shift of up to 0.3 eV. Decay dynamics of the observed emission contains fast (nanosecond) and slow (microseconds) components, indicating contributions of several relaxation channels. Based on these material characteristics, a possible microscopic origin of the individual emission bands is discussed.

Stratigraphic setting and mineralogy of the Arctic volcanogenic massive sulfide prospect, Ambler district, Alaska.

Science.gov (United States)

Schmidt, J.M.

1986-01-01

The Arctic prospect, south central Brooks Range, is among the 30 largest of 508 volcanic-hosted massive sulphide deposits in the world. The massive sulphide lenses are interlayered with graphitic schist between metamorphosed rhyolite porphyries in Middle Devonian to early Mississippian metamorphosed volcanic, volcaniclastic and sedimentary rocks. Hydrothermal alteration is of three types: chloritic, phyllic s.l., and pyrite-phengite, each type strata-distinctively and respectively below, in, and above the sulphides. Maximum alteration conforms with metal zoning in the sulfides to suggest predominantly northwestward dispersal from a linear vent area in the elongate basin containing the deposit.-G.J.N.

Sulfur accumulation and atmospherically deposited sulfate in the Lake States.

Science.gov (United States)

Mark B. David; George Z. Gernter; David F. Grigal; Lewis F. Ohmann

1989-01-01

Characterizes the mass of soil sulfur (adjusted for nitrogen), and atmospherically deposited sulfate along an acid precipitation gradient from Minnesota to Michigan. The relationship of these variables, presented graphically through contour mapping, suggests that patterns of atmospheric wet sulfate deposition are reflected in soil sulfur pools.

High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

Science.gov (United States)

Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

2014-01-01

Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

Effect of pH on optic and structural characterization of chemical deposited AgI thin films

Energy Technology Data Exchange (ETDEWEB)

Tezel, Fatma Meydaneri [Department of Metallurgy and Materials Engineering, Karabük University (Turkey); Kariper, İshak Afşin [Department of Science Education, Faculty of Education, Erciyes University, Kayseri (Turkey)

2017-11-15

AgI thin films were grown on amorphous commercial glass substrates with chemical bath deposition (CBD) at different pH values (2, 3, 4, 5, 6), 6 hours deposition time and 60 °C. The structure of the nanocrystals was characterized by X-ray diffraction (XRD). The ratio of Ag{sup +} and I{sup -} ions changed the crystalline structures. The presence of the Ag{sup +} ions produces the γ-phase of AgI and excess of iodine concentration produces β-phase of AgI. The pH: 4 was like a transition pH for these phases. The number of crystallites per unit area has maximum value at pH: 5, as the structure is re-crystallization to hexagonal phase. Also, the thicknesses of produced thin films were decreased with increased pH values. Therefore, transmission, reflection, extinction coefficients and refractive index of the materials were affected by thicknesses, and calculated to be 32, 35, 3, 11, 9 (%) - 27, 25, 61, 45, 49 (%) - 0.036, 0.032, 0.067, 0.107, 0.075 and 3.21, 3.02, 5.16, 8.35, 5.70 in 550 nm at pH: 2-3-4-5-6 values, respectively. The exciton peaks of AgI were observed at between 320 and 420 nm. Surface properties were investigated by using scanning electron microscopy (SEM). (author)

Study on geologic structure of hydrogenic deposits

International Nuclear Information System (INIS)

1985-01-01

The problem of studying geologic structure of hydrogenic uranium deposits developed by underground leaching (UL), is elucidated. Geologic maps of the surface are used to characterize engineering and geologic conditions. Main geologoic papers are maps drawn up according to boring data. For total geologic characteristic of the deposit 3 types of maps are usually drawn up: structural maps of isohypses or isodepths, lithologic-facies maps on the horizon and rhythm, and maps of epigenetic alterations (geochemmcal). Besides maps systems of sections are drawn up. Problems of studying lithologic-facies and geohemical peculiarities of deposits, epigenotic alterations, substance composition of ores and enclosing rocks, documentation and core sampting, are considered in details

Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films - Coating characterization and first cell biological results.

Science.gov (United States)

Strąkowska, Paulina; Beutner, René; Gnyba, Marcin; Zielinski, Andrzej; Scharnweber, Dieter

2016-02-01

Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD>HAp/B-NCD>uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

Characterization of the yttria-stabilized zirconia thin film electrophoretic deposited on La{sub 0.8}Sr{sub 0.2}MnO{sub 3} substrate

Energy Technology Data Exchange (ETDEWEB)

Yang, Koho [Department of Mold and Die Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Rode, Kaohsiung 80782, Taiwan (China); Shen, Jung-Hsiung [Department of Mold and Die Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Rode, Kaohsiung 80782, Taiwan (China); Yang, Kai-Yun [Department of Materials Science and Engineering, National Chen Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Hung, I-Ming [Department of Materials Science and Engineering, National Chen Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Department of Chemical Engineering and Materials Science, Yuan Ze University, 135 Yuan-Tung Road, Chungli, Taoyunn 320, Taiwan (China); Fung, Kuan-Zong [Department of Materials Science and Engineering, National Chen Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, Moo-Chin [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan (China)]. E-mail: mcwang@kmu.edu.tw

2007-06-14

The yttria-stabilized zirconia (YSZ) thin films electrophoretic deposited on the La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSM) substrate have been characterized by using zeta potential analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The La{sub 2}Zr{sub 2}O{sub 7} (LZ) formed at the interface between the YSZ thin film and LSM substrate, after sintered at 1400 {sup o}C for 52 h, are identified by XRD. The zeta potential of the YSZ particles in pure ethanol-acetone is about 7.8 mV, but when the I{sub 2} concentration is greater than 0.6 g/1, the zeta potential attains a constant value, 46 mV. The relation between deposit weight of the YSZ films and the applied voltage shows a non-linear behavior. Thickness of the YSZ thin film deposited on the LSM substrate by electrophoretic deposition is controlled by a diffusion process. A larger LZ with the thickness of 200 nm is formed at the interface between the YSZ film and the LSM substrate.

Electrodeposition of Ni-W Alloy and Characterization of Microstructure and Properties of the Deposits

DEFF Research Database (Denmark)

Mizushima, Io

2007-01-01

of the electrolyte. Simultaneously, the presence of carbon is observed with GDOES in layers deposited from the aged electrolyte. The carbon dissolution in the Ni-W alloy deposit is associated with the formation of a new phase in the electrodeposit, giving rise to the anomalous Bragg peak. In Chapter 8 hardness....... The experimental results of the present work are given in the chapters 4-9. In Chapter 4 development of a new electrolyte for Ni-W alloys is described. In the chapters 5-9 the properties of the Ni-W alloys such as residual stress, microstructure, hardness and thermal stability are investigated. Furthermore......, grain size and thermal stability of nickel and Ni-W alloy layers deposited from electrolytes containing equal amounts of citrate, glycine and triethanolamine are investigated. The hardness of the deposits was investigated in the as-deposited layer as well as after annealing for 1 hour at temperatures up...

Initial deposition and electron paramagnetic resonance defects characterization of TiO2 films prepared using successive ionic layer adsorption and reaction method

International Nuclear Information System (INIS)

Wu Yiyong; Shi Yaping; Xu Xianbin; Sun Chengyue

2012-01-01

Successive ionic layer adsorption and reaction (SILAR) technique was considered promisingly to deposit ultra thin titanium dioxide (TiO 2 ) films under ambient condition. In this paper, the growth process, structures and paramagnetic defects of the films were characterized by complementary techniques of atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and electron paramagnetic resonance spectroscopy. The results indicate that on glass substrate the SILAR TiO 2 film nucleates in an island mode within the initial five deposition cycles but grows in a layer-by-layer mode afterwards. The growth rate was measured as 4.6 Å/cycle. In the as-deposited films, a kind of paramagnetic defects is detected at g (2.0029) and it can be attributed to oxygen vacancies. These as-received oxygen vacancies could be annealed out at 473 K. Ultraviolet irradiation on the as-deposited films can also decrease the density of the defects. The relative mechanisms on the phenomenon were discussed in this paper. - Highlights: ► TiO 2 films are deposited on glass at 25 °C by successive ionic layer adsorption and reaction method with a rate of 4.6 Å/cycle. ► The films nucleate in an island mode initially but grow in a layer mode afterwards. ► The SILAR TiO 2 films nucleation period is five cycles. ► Electron paramagnetic resonance spectroscopy shows that TiO 2 films paramagnetic defects are attributed to oxygen vacancies. ► They will decrease by anneal or ultraviolet radiation and form hydroxyl or superoxide radicals.

(Invited) Atomic Layer Deposition for Novel Dye-Sensitized Solar Cells

KAUST Repository

Tétreault, Nicolas

2011-01-01

Herein we present the latest fabrication and characterization techniques for atomic layer deposition of Al 2O 3, ZnO, SnO 2, Nb 2O 5, HfO 2, Ga 2O 3 and TiO 2 for research on dye-sensitized solar cell. In particular, we review the fabrication of state-of-the-art 3D host-passivation-guest photoanodes and ZnO nanowires as well as characterize the deposited thin films using spectroscopic ellipsometry, X-ray diffraction, Hall effect, J-V curves and electrochemical impedance spectroscopy. ©The Electrochemical Society.

Plasma sprayed and electrospark deposited zirconium metal diffusion barrier coatings

International Nuclear Information System (INIS)

Hollis, Kendall J.; Pena, Maria I.

2010-01-01

Zirconium metal coatings applied by plasma spraying and electrospark deposition (ESD) have been investigated for use as diffusion barrier coatings on low enrichment uranium fuel for research nuclear reactors. The coatings have been applied to both stainless steel as a surrogate and to simulated nuclear fuel uranium-molybdenum alloy substrates. Deposition parameter development accompanied by coating characterization has been performed. The structure of the plasma sprayed coating was shown to vary with transferred arc current during deposition. The structure of ESD coatings was shown to vary with the capacitance of the deposition equipment.

Sputter deposition of tantalum-nitride films on copper using an rf-plasma

International Nuclear Information System (INIS)

Walter, K.C.; Fetherston, R.P.; Sridharan, K.; Chen, A.; Shamim, M.M.; Conrad, J.R.

1994-01-01

A tantalum-nitride film was successfully deposited at ambient temperature on copper with a modified ion-assisted-deposition (IAD) technique. The process uses an argon and nitrogen plasma to sputter deposit from a tantalum rf-cathode and ion implant the deposited film simultaneously. Both argon and nitrogen ions are used for sputtering and ion implantation. Auger spectroscopy and x-ray diffraction were used to characterize the resulting film

Recognition of primary and diagenetic magnetizations to determine the magnetic polarity record and timing of deposition of the moat-fill rocks of the Oligocene Creede Caldera, Colorado

Science.gov (United States)

Reynolds, Richard L.; Rosenbaum, Joseph G.; Sweetkind, Donald S.; Lanphere, Marvin A.; Robert, Andrew P.; Verosub, Kenneth L.

2000-01-01

Sedimentary and volcaniclastic rocks of the Oligocene Creede Formation fill the moat of the Creede caldera, which formed at about 26.9 Ma during the eruption of the Snowshoe Mountain Tuff. Paleomagnetic and rock magnetic studies of two cores (418 and 703 m long) that penetrated the lower half of the Creede Formation, in addition to paleomagnetic and isotopic dating studies of stratigraphically bracketing volcanic units, provide information on the age and the time span of sedimentation of the caldera fill. Normal polarity magnetization are found in Snowshoe Mountain Tuff beneath the moat sediments; in detrital-magnetite-bearing graded tuffs near the bottom of the moat fill; in an ash-fall deposit about 200 m stratigraphically about the top of core 2; and in postcaldera lava flows of the Fisher Dacite that overlie the Creede Formation. Normal polarity also characterizes detrital-magnetite-bearing tuff and sandstone unites within the caldera moat rocks that did not undergo severe sulfidic alteration. The combination of initially low magnitude of remanent magnetization and the destructive effects of subsequent diagenetic sulfidization on detrital iron oxides results in a poor paleomagnetic record for the fine-grained sedimentary rocks of the Creede Formation. these fine-grained rocks have either normal or revered polarity magnetizations that are carried by magnetite and/or maghemite. Many more apparent reversals are found that can be accommodated by any geomagnetic polarity time scale over the interval spanned by the ages of the bracketing extrusive rocks. Moreover, opposite polarity magnetization are found in specimens separated by only a few centimeters, without intervening hiatuses, and by specimens in several tuff beds, each of which represents a single depositional event. These polarity changes cannot, therefore, be attributed to detrital remanent magnetization. Many polarity changes are apparently related to chemical remanent magnetizations carried by

Characterization of herbaspirillum- and limnobacter-related strains isolated from young volcanic deposits in miyake-jima island, Japan.

Science.gov (United States)

Lu, Hongsheng; Fujimura, Reiko; Sato, Yoshinori; Nanba, Kenji; Kamijo, Takashi; Ohta, Hiroyuki

2008-01-01

The role of microbes in the early development of ecosystems on new volcanic materials seems to be crucial to primary plant succession but is not well characterized. Here we analyzed the bacterial community colonizing 22-year-old volcanic deposits of the Miyake-jima Island (Japan) using culture-based and 16S rRNA gene clone library methods. The majority of 91 bacterial isolates were placed phylogenetically in two clusters (A and B) of the Betaproteobacteria. Cluster A (82% of isolates) was related to the genus Limnobacter and Cluster B (9%) was affiliated with the Herbaspirillum clade. The clone library analysis supported the predominance of Cluster B rather than Cluster A. Strain KP1-50 of Cluster B was able to grow on a mineral medium under an atmosphere of H(2), O(2), and CO(2) (85:5:10), and characterized by its large-subunit gene of ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL) and nitrogenase reductase gene (nifH). In contrast, strains of Cluster A did not grow chemolithoautotrophically with H(2), O(2), and CO(2) but increased their cell biomass with the addition of thiosulfate to the succinate medium, suggesting the use of thiosulfate as an energy source. From phenotypic characterization, it was suggested that the Cluster A and B strains were novel species in the genus Limnobacter and Herbaspirillum, respectively.

Characterization of deposits formed on catalyst surfaces during hydrotreatment of coal-derived liquids

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.

1982-04-01

Loss of catalyst activity is attributed to the formation of polynuclear aromatic structures on the surface. Heavy species containing N and O heteroatoms were also present in deposits. Phenols, aromatic and heterocyclic compounds are considered to be the precursors for the formation of the deposits. (16 refs.)

Growth and characterization of indium tin oxide thin films deposited on PET substrates

International Nuclear Information System (INIS)

Lee, Jaehyeong; Jung, Hakkee; Lee, Jongin; Lim, Donggun; Yang, Keajoon; Yi, Junsin; Song, Woo-Chang

2008-01-01

Transparent and conductive indium tin oxide (ITO) thin films were deposited onto polyethylene terephthalate (PET) by d.c. magnetron sputtering as the front and back electrical contact for applications in flexible displays and optoelectronic devices. In addition, ITO powder was used for sputter target in order to reduce the cost and time of the film formation processes. As the sputtering power and pressure increased, the electrical conductivity of ITO films decreased. The films were increasingly dark gray colored as the sputtering power increased, resulting in the loss of transmittance of the films. When the pressure during deposition was higher, however, the optical transmittance improved at visible region of light. ITO films deposited onto PET have shown similar optical transmittance and electrical resistivity, in comparison with films onto glass substrate. High quality films with resistivity as low as 2.5 x 10 -3 Ω cm and transmittance over 80% have been obtained on to PET substrate by suitably controlling the deposition parameters

Investigation of deposition characteristics and properties of high-rate deposited silicon nitride films prepared by atmospheric pressure plasma chemical vapor deposition

International Nuclear Information System (INIS)

Kakiuchi, H.; Nakahama, Y.; Ohmi, H.; Yasutake, K.; Yoshii, K.; Mori, Y.

2005-01-01

Silicon nitride (SiN x ) films have been prepared at extremely high deposition rates by the atmospheric pressure plasma chemical vapor deposition (AP-PCVD) technique on Si(001) wafers from gas mixtures containing He, H 2 , SiH 4 and N 2 or NH 3 . A 150 MHz very high frequency (VHF) power supply was used to generate high-density radicals in the atmospheric pressure plasma. Deposition rate, composition and morphology of the SiN x films prepared with various deposition parameters were studied by scanning electron microscopy and Auger electron spectroscopy. Fourier transformation infrared (FTIR) absorption spectroscopy was also used to characterize the structure and the chemical bonding configurations of the films. Furthermore, etching rate with buffered hydrofluoric acid (BHF) solution, refractive index and capacitance-voltage (C-V) characteristics were measured to evaluate the dielectric properties of the films. It was found that effective passivation of dangling bonds and elimination of excessive hydrogen atoms at the film-growing surface seemed to be the most important factor to form SiN x film with a dense Si-N network. The C-V curve of the optimized film showed good interface properties, although further improvement was necessary for use in the industrial metal-insulator-semiconductor (MIS) applications

Deposition and characterization of TaAIN thin films by reactive magnetron sputtering; Deposicao e caracterizacao de filmes finos de TaAIN depositados por magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Oliveira, G.B.; Fernandez, D.R.; Fontes Junior, A.S.; Felix, L.C.; Tentardini, E.K. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Ciencia e Engenharia de Materiais; Hubler, R. [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), RS (Brazil); Silva Junior, A.H. da, E-mail: brito-g@hotmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

2016-07-01

Phase stability, oxidation resistance and great mechanical properties are the main objectives when synthesizing protective coatings. The tantalum nitride (TaN) has aroused interest because of its high temperature stability, chemical inertness and thermal conductivity. However, it has a low hardness value when compared to other coatings. Researches has shown that one way to improvements in the properties of a thin film is by adding other elements in the deposition process. Therefore, the objective of this study was to deposit thin films of TaAlN by magnetron sputtering, changing the aluminum concentration of 2, 5, 7, to 14%. Then the coatings were characterized by EDS, RBS, GIXRD and nanohardness. In this study was found that the aluminum deposited did not change the oxidation resistance of the coating, and the highest value of hardness was 28 GPa for the sample with 14 at.%. (author)

Evidence for large-magnitude, post-Eocene extension in the northern Shoshone Range, Nevada, and its implications for Carlin-type gold deposits in the lower plate of the Roberts Mountains allochthon

Science.gov (United States)

Colgan, Joseph P.; Henry, Christopher D.; John, David A.

2014-01-01

The northern Shoshone and Toiyabe Ranges in north-central Nevada expose numerous areas of mineralized Paleozoic rock, including major Carlin-type gold deposits at Pipeline and Cortez. Paleozoic rocks in these areas were previously interpreted to have undergone negligible postmineralization extension and tilting, but here we present new data that suggest major post-Eocene extension along west-dipping normal faults. Tertiary rocks in the northern Shoshone Range crop out in two W-NW–trending belts that locally overlie and intrude highly deformed Lower Paleozoic rocks of the Roberts Mountains allochthon. Tertiary exposures in the more extensive, northern belt were interpreted as subvertical breccia pipes (intrusions), but new field data indicate that these “pipes” consist of a 35.8 Ma densely welded dacitic ash flow tuff (informally named the tuff of Mount Lewis) interbedded with sandstones and coarse volcaniclastic deposits. Both tuff and sedimentary rocks strike N-S and dip 30° to 70° E; the steeply dipping compaction foliation in the tuffs was interpreted as subvertical flow foliation in breccia pipes. The southern belt along Mill Creek, previously mapped as undivided welded tuff, includes the tuff of Cove mine (34.4 Ma) and unit B of the Bates Mountain Tuff (30.6 Ma). These tuffs dip 30° to 50° east, suggesting that their west-dipping contacts with underlying Paleozoic rocks (previously mapped as depositional) are normal faults. Tertiary rocks in both belts were deposited on Paleozoic basement and none appear to be breccia pipes. We infer that their present east tilt is due to extension on west-dipping normal faults. Some of these faults may be the northern strands of middle Miocene (ca. 16 Ma) faults that cut and tilted the 34.0 Ma Caetano caldera ~40° east in the central Shoshone Range (

Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films — Coating characterization and first cell biological results

Energy Technology Data Exchange (ETDEWEB)

Strąkowska, Paulina [Gdańsk University of Technology, Mechanical Engineering Faculty (Poland); Gdańsk University of Technology, Faculty of Electronics, Telecommunications, and Informatics (Poland); Beutner, René [Max Bergmann Center, Technische Universität Dresden (Germany); Gnyba, Marcin [Gdańsk University of Technology, Faculty of Electronics, Telecommunications, and Informatics (Poland); Zielinski, Andrzej [Gdańsk University of Technology, Mechanical Engineering Faculty (Poland); Scharnweber, Dieter, E-mail: Dieter.Scharnweber@tu-dresden.de [Max Bergmann Center, Technische Universität Dresden (Germany)

2016-02-01

Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD > HAp/B-NCD > uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films — Coating characterization and first cell biological results

International Nuclear Information System (INIS)

Strąkowska, Paulina; Beutner, René; Gnyba, Marcin; Zielinski, Andrzej; Scharnweber, Dieter

2016-01-01

Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD > HAp/B-NCD > uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

ZnSe thin films by chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Lokhande, C.D.; Patil, P.S.; Tributsch, H. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CS, Glienicker Strasse-100, D-14109 Berlin (Germany); Ennaoui, A. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CG, Glienicker Strasse-100, D-14109 Berlin (Germany)

1998-09-04

The ZnSe thin films have been deposited onto glass substrates by the simple chemical bath deposition method using selenourea as a selenide ion source from an aqueous alkaline medium. The effect of Zn ion concentration, bath temperature and deposition time period on the quality and thickness of ZnSe films has been studied. The ZnSe films have been characterized by XRD, TEM, EDAX, TRMC (time-resolved microwave conductivity), optical absorbance and RBS techniques for their structural, compositional, electronic and optical properties. The as-deposited ZnSe films are found to be amorphous, Zn rich with optical band gap, Eg, equal to 2.9 eV

Zn–Mn alloy coatings from acidic chloride bath: Effect of deposition conditions on the Zn–Mn electrodeposition-morphological and structural characterization

Energy Technology Data Exchange (ETDEWEB)

Loukil, N., E-mail: nloukil87@gmail.com; Feki, M.

2017-07-15

Highlights: • Zn-Mn co-deposition from an additives-free chloride bath is possible. • Effect of Mn{sup 2+} ion concentration and current density on Zn-Mn electrodeposition and particularly Mn content into Zn-Mn deposits were investigated. • A dimensionless graph model was used to analyze the effect of Mn{sup 2+} ion concentration as well as the applied potential on Zn-Mn nucleation process. • Effect of current density on the morphology and structure of Zn-Mn alloys deposits. • A transition from crystalline to amorphous structure may occur in the Mn alloy electrodeposits at high current densities. - Abstract: Zn–Mn alloy electrodeposition on steel electrode in chloride bath was investigated using cyclic voltammetric, chronopotentiometric and chronoamperometric techniques. Cyclic voltammetries (CV) reveal a deep understanding of electrochemical behaviors of each metal Zn, Mn, proton discharge and Zn–Mn co-deposition. The electrochemical results show that with increasing Mn{sup 2+} ions concentration in the electrolytic bath, Mn{sup 2+} reduction occurs at lower over-potential leading to an enhancement of Mn content into the Zn–Mn deposits. A dimensionless graph model was used to analyze the effect of Mn{sup 2+} ions concentration on Zn–Mn nucleation process. It was found that the nucleation process is not extremely affected by Mn{sup 2+} concentration. Nevertheless, it significantly depends on the applied potential. Several parameters such as Mn{sup 2+} ions concentration, current density and stirring were investigated with regard to the Mn content into the final Zn–Mn coatings. It was found that the Mn content increases with increasing the applied current density j{sub imp} and Mn{sup 2+} ions concentration in the electrolytic bath. However, stirring of the solution decreases the Mn content in the Zn–Mn coatings. The phase structure and surface morphology of Zn–Mn deposits are characterized by means of X-ray diffraction analysis and Scanning

Characterization of photoluminescent europium doped yttrium oxide thin-films prepared by metallorganic chemical vapor deposition

International Nuclear Information System (INIS)

McKittrick, J.; Bacalski, C.F.; Hirata, G.A.; Hubbard, K.M.; Pattillo, S.G.; Salazar, K.V.; Trkula, M.

1998-01-01

Europium doped yttrium oxide, (Y 1-x Eu x ) 2 O 3 , thin-films were deposited on silicon and sapphire substrates by metallorganic chemical vapor deposition (MOCVD). The films were grown in a MOCVD chamber reacting yttrium and europium tris(2,2,6,6-tetramethyl-3,5,-heptanedionates) precursors in an oxygen atmosphere at low pressures (5 Torr) and low substrate temperatures (500--700 C). The films deposited at 500 C were flat and composed of nanocrystalline regions of cubic Y 2 O 3 , grown in a textured [100] or [110] orientation to the substrate surface. Films deposited at 600 C developed from the flat, nanocrystalline morphology into a plate-like growth morphology oriented in the [111] with increasing deposition time. Monoclinic Y 2 O 3 :Eu 3+ was observed in x-ray diffraction for deposition temperatures ≥600 C on both (111) Si and (001) sapphire substrates. This was also confirmed by the photoluminescent emission spectra

Characterization of transparent silica films deposited on polymeric materials

International Nuclear Information System (INIS)

Teshima, K.; Sugimura, H.; Inoue, Y.; Takai, O.

2002-01-01

Silica films were synthesized by capacitively coupled RF PECVD using mixtures of organo-silane and oxygen as a source. The chemical bonding states and compositions of the films deposited were evaluated with FTIR and XPS. Film surfaces and cross-sections were observed by SEM. Oxygen transmission rates (OTR) of the films coated on polyethylene terephthalate (PET) substrates were measured by an isopiestic method. (Authors)

Deposition and characterization of ITO films produced by laser ablation at 355 nm

DEFF Research Database (Denmark)

Holmelund, E.; Thestrup Nielsen, Birgitte; Schou, Jørgen

2002-01-01

Indium tin oxide (ITO) films have been deposited by pulsed laser deposition (PLD) at 355 nm. Even though the absorption of laser light at the wavelength 355 nm is much smaller than that of the standard excimer lasers for PLD at 248 nm and 193 nm, high-quality films can be produced. At high fluence...

Characterization of Particulate Matter Profiling and Alveolar Deposition from Biomass Burning in Northern Thailand: The 7-SEAS Study

Science.gov (United States)

Chuang, Hsiao-Chi; Hsiao, Ta-Chih; Wang, Sheng-Hsiang; Tsay, Si-Chee; Lin, Neng-Huei

2016-01-01

Biomass burning (BB) frequently occurs in SouthEast Asia (SEA), which significantly affects the air quality and could consequently lead to adverse health effects. The aim of this study was to characterize particulate matter (PM) and black carbon (BC) emitted from BB source regions in SEA and their potential of deposition in the alveolar region of human lungs. A 31-day characterization of PM profiling was conducted at the Doi Ang Khang (DAK) meteorology station in northern Thailand in March 2013. Substantial numbers of PM (10147 +/- 5800 # per cubic centimeter) with a geometric mean diameter (GMD) of 114.4 +/- 9.2 nm were found at the study site. The PM of less than 2.5 micron in aerodynamic diameter (PM sub 2.5) hourly-average mass concentration was 78.0 +/- 34.5 per cubic microgram whereas the black carbon (BC) mass concentration was 4.4 +/- 2.6 micrograms per cubic meter. Notably, high concentrations of nanoparticle surface area (100.5 +/- 54.6 square micrometers per cubic centimeter) emitted from biomass burning can be inhaled into the human alveolar region. Significant correlations with fire counts within different ranges around DAK were found for particle number, the surface area concentration of alveolar deposition, and BC. In conclusion, biomass burning is an important PM source in SEA, particularly nanoparticles, which has high potency to be inhaled into the lung environment and interact with alveolar cells, leading to adverse respiratory effects. The fire counts within 100 to 150 km shows the highest Pearson's r for particle number and surface area concentration. It suggests 12 to 24 hr could be a fair time scale for initial aging process of BB aerosols. Importantly, the people lives in this region could have higher risk for PM exposure.

Indium sulfide buffer layers deposited by dry and wet methods

International Nuclear Information System (INIS)

Asenjo, B.; Sanz, C.; Guillen, C.; Chaparro, A.M.; Gutierrez, M.T.; Herrero, J.

2007-01-01

Indium sulfide (In 2 S 3 ) thin films have been deposited on amorphous glass, glass coated by tin oxide (TCO) and crystalline silicon substrates by two different methods: modulated flux deposition (MFD) and chemical bath deposition (CBD). Composition, morphology and optical characterization have been carried out with Scanning Electron Microscopy (SEM), IR-visible-UV Spectrophotometry, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrometer. Different properties of the films have been obtained depending on the preparation techniques. With MFD, In 2 S 3 films present more compact and homogeneous surface than with CBD. Films deposited by CBD present also indium oxide in their composition and higher absorption edge values when deposited on glass

Structural characterization of thin films of titanium nitride deposited by laser ablation

International Nuclear Information System (INIS)

Castro C, M.A.; Escobar A, L.; Camps C, E.; Mejia H, J.A.

2004-01-01

Thin films of titanium nitride were deposited using the technique of laser ablation. It was studied the effect of the density of laser energy used for ablation the target as well as of the pressure of the work gas about the structure and the hardness of the deposited thin films. Depending on the pressure of the work gas films was obtained with preferential orientation in the directions (200) and (111). At a pressure of 1 x 10 -2 Torr only the direction (200) was observed. On the other hand to the pressure of 5 x 10 -3 Torr the deposited material this formed by a mixture of the orientation (200) and (111), being the direction (111) the predominant one. Thin films of Ti N were obtained with hardness of up to 24.0 GPa that makes to these attractive materials for mechanical applications. The hardness showed an approximately linear dependence with the energy density. (Author)

Characterization of CuS nanocrystalline thin films synthesized by chemical bath deposition and dip coating techniques

International Nuclear Information System (INIS)

Chaki, Sunil H.; Deshpande, M.P.; Tailor, Jiten P.

2014-01-01

CuS thin films were synthesized by chemical bath deposition and dip coating techniques at ambient temperature. The energy dispersive analysis of X-rays of the thin films confirmed that both the as synthesized thin films are stoichiometric. The X-ray diffraction of the chemical bath deposited and dip coating deposited thin films showed that the films possess hexagonal structure having lattice parameters, a = b = 3.79 A and c = 16.34 A. The crystallite sizes determined from the X-ray diffraction data using Scherrer's formula for the chemical bath deposition and dip coating deposition thin films came out to be nearly 11 nm and 13 nm, respectively. The optical microscopy of the as deposited thin films surfaces showed that the substrates are well covered in both the deposited films. The scanning electron microscopy of the thin films clearly showed that in chemical bath deposited thin films the grain size varies from few μm to nm, while in dip coating deposited films the grain size ranges in nm. The optical bandgap determined from the optical absorbance spectrum analysis showed, chemical bath deposited thin films possess direct bandgap of 2.2 eV and indirect bandgap of 1.8 eV. In the case of dip coating deposited thin films, the direct bandgap is 2.5 eV and indirect bandgap is 1.9 eV. The d.c. electrical resistivity variation with temperature for both the deposited films showed that the resistivity decreases with temperature thus confirming the semiconducting nature. The thermoelectric power variations with temperature and the room temperature Hall Effect study of both the synthesized CuS thin films showed them to be of p-type conductivity. The obtained results are discussed in details. - Highlights: • CuS thin films were synthesized by chemical bath deposition and dip coating techniques. • The films possessed hexagonal structure. • The optical absorption showed that the films had direct and indirect bandgap. • Study of electrical transport properties

Geochemical Data for Samples Collected in 2007 Near the Concealed Pebble Porphyry Cu-Au-Mo Deposit, Southwest Alaska

Science.gov (United States)

Fey, David L.; Granitto, Matthew; Giles, Stuart A.; Smith, Steven M.; Eppinger, Robert G.; Kelley, Karen D.

2008-01-01

In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of

Cadmium sulfide thin films growth by chemical bath deposition

Science.gov (United States)

Hariech, S.; Aida, M. S.; Bougdira, J.; Belmahi, M.; Medjahdi, G.; Genève, D.; Attaf, N.; Rinnert, H.

2018-03-01

Cadmium sulfide (CdS) thin films have been prepared by a simple technique such as chemical bath deposition (CBD). A set of samples CdS were deposited on glass substrates by varying the bath temperature from 55 to 75 °C at fixed deposition time (25 min) in order to investigate the effect of deposition temperature on CdS films physical properties. The determination of growth activation energy suggests that at low temperature CdS film growth is governed by the release of Cd2+ ions in the solution. The structural characterization indicated that the CdS films structure is cubic or hexagonal with preferential orientation along the direction (111) or (002), respectively. The optical characterization indicated that the films have a fairly high transparency, which varies between 55% and 80% in the visible range of the optical spectrum, the refractive index varies from 1.85 to 2.5 and the optical gap value of which can reach 2.2 eV. It can be suggested that these properties make these films perfectly suitable for their use as window film in thin films based solar cells.

Stratigraphy, sedimentology, and geothermal reservoir potential of the volcaniclastic Cura-Mallín succession at Lonquimay, Chile

Science.gov (United States)

Pedroza, Viviana; Le Roux, Jacobus P.; Gutiérrez, Néstor M.; Vicencio, Vladimir E.

2017-08-01

The Tolhuaca Volcano near Lonquimay in south-central Chile has been the subject of several studies due to its geothermal manifestations, but little is known about the stratigraphy and reservoir potential of the Cura-Mallín Formation forming its basement. Field work and U-Pb dating of detrital zircons allow us to redefine this succession as the Cura-Mallín Group, consisting of the volcano-sedimentary Guapitrío Formation, sedimentary Río Pedregoso Formation, and volcano-sedimentary Mitrauquén Formation. The Río Pedregoso Formation can be subdivided into three formal units, namely the Quilmahue Member, Rucañanco Member, and Bío-Bío Member. The base of the Quilmahue Member interfingers laterally with the base of the Guapitrío Formation, for which a previous K/Ar date of 22.0 ± 0.9 Ma was apparently discarded by the original authors. However, this date is consistent with the stratigraphic position of the Quilmahue Member and new zircon dates from the overlying units, also coinciding with the initiation of an extensional phase in the Bíobío-Aluminé Basin. Deposition of the Quilmahue Member continued throughout the early Miocene, as confirmed by dates of 17.5 Ma reported by previous authors and 16.5 Ma obtained in this study. The Rucañanco Member was deposited during the Serravalian around 12.6 Ma, whereas the Bío-Bío Member was dated at the Serravalian-Tortonian limit (11.6 Ma). Although all three members were deposited in a fluvio-lacustrine environment, they were dominated respectively by flood plains with crevasse splays, lake margins with distributary mouth bars and Gilbert-type deltas, and distal braided and meandering rivers. Whereas the Quilmahue Member was deposited during basin extension, the Rucañanco Member was formed during a period of basin inversion and compression. Temporary tectonic quiescence during deposition of the Bío-Bío Member allowed denudation of the landscape, but around 9.5 Ma tectonism was renewed again during deposition of

Selective tungsten deposition in a batch cold wall CVD system

International Nuclear Information System (INIS)

Chow, R.; Kang, S.; Harshbarger, W.R.; Susoeff, M.

1987-01-01

Selective deposition of tungsten offers many advantages for VLSI technology. The process can be used as a planarization technique for multilevel interconnect technology, it can be used to fill contacts and to provide a barrier layer between Al and Si materials, and the selective W process might be used as a self-aligned technology to provide low resistance layers on source/drain and gate conductors. Recent publications have indicate that cold wall CVD systems provide advantages for development of selective W process. Genus has investigated selective W deposition processing, and we have developed a selective W deposition process for the Genus 8402 multifilm deposition system. This paper describes the Genus 8402 system and the selective W process developed in this reactor. To further develop selective W technology, Genus has signed an agreement with General Electric establishing a joint development program. As a part of this program, the authors characterized the selective W process for encroachment, Si consumption and degrees of selectivity on various dielectrics. The status of this development activity and process characterization is reviewed in this paper

Problems related to the determination of mass densities of evaporated reference deposits

Science.gov (United States)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Van Gestel, J.; Eykens, R.; Gilliam, D. M.; Scott, R. D.; Byrne, J.; Dawber, P.

1991-05-01

The accurate characterization of the surface density (nuclei/cm 2) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than ± 0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of 6LiF and 10B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results.

Characterization of bicrystalline epitaxial LaNiO{sub 3} films fabricated on MgO (1 0 0) substrates by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Zheng Liang [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China); Zhu Jun [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China)]. E-mail: junzhu@uestc.edu.cn; Zhang Ying [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China); Jiang Shuwen [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China); Li Yanrong [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China); Huawei Xian [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China); Li Jinlong [School of Microelectronics and Solid-State Electronics, University of Electronics Science and Technology of China, Chengdu 610054 (China)

2006-03-15

A series of metallic LaNiO{sub 3} (LNO) thin films were deposited on MgO (1 0 0) substrates by pulsed laser deposition (PLD) under the oxygen pressure of 20 Pa at different substrate temperatures from 450 to 750 deg. C. X-ray diffraction (XRD) was used to characterize the crystal structure of LNO films. {theta}-2{theta} scans of XRD indicate that LNO film deposited at a substrate temperature of 700 deg. C has a high orientation of (l l 0). At other substrate temperatures, the LNO films have mixed phases of (l l 0) and (l 0 0). Furthermore, pole figure measurements show that LNO thin films, with the bicrystalline structure, were epitaxially deposited on MgO (1 0 0) substrates in the mode of LNO (1 1 0)//MgO (1 0 0) at 700 deg. C. Reflection high-energy electric diffraction (RHEED) and atomic force microscopy (AFM) were also performed to investigate the microstructure of LNO films with the high (l l 0) orientation. RHEED patterns clearly confirm this epitaxial relationship. An atomically smooth surface of LNO films at 700 deg. C was obtained. In addition, bicrystalline epitaxial LNO films, fabricated at 700 deg. C, present a excellent conductivity with a lower electrical resistivity of 300 {mu} {omega} cm. Thus, the obtained results indicate that bicystalline epitaxial LNO films could serve as a promising candidate of electrode materials for the fabrication of ferroelectric or dielectric films.

Optical and structural characterization of nickel oxide-based thin films obtained by chemical bath deposition

International Nuclear Information System (INIS)

Vidales-Hurtado, M.A.; Mendoza-Galvan, A.

2008-01-01

Nickel oxide-based thin films were obtained using the chemical bath deposition method on glass and silicon substrates. The precursor solution used was a mixture of nickel nitrate, urea, and deionized water. Molar concentration of nickel (0.3-1.0 M), deposition time, and immersing cycles were considered as deposition variables. Infrared spectroscopy and X-ray diffraction data reveal that all as-deposited films correspond to the transparent turbostratic phase α(II)-Ni(OH) 2 . However, the rate of deposition depends on nickel content in the solution. After annealing in air at temperatures above of 300 deg. C, the films are transformed to the NiO phase and show a grey/black color. In these films, scanning electron microscopy images show aggregates of thin stacked sheets on their surface, such aggregates can be easily removed leaving only a thin NiO layer of about 30 nm adhered firmly to the substrate, regardless of nickel concentration in the solution and deposition time. In order to obtain thicker NiO films with good optical properties a procedure is developed performing several immersing-annealing cycles

Characterization of sands and mineral clays in channel and floodplain deposits of Portuguesa river, Venezuela

Directory of Open Access Journals (Sweden)

Orlando José González Clemente

2013-11-01

Full Text Available In the main channel and floodplain of Portuguesa River were studied the mineralogical characteristics of sand and clay minerals respectively. The methodology consisted of X-ray diffraction (XRD analysis, for both mineral fractions. The results indicated the presence of mainly of quartz sands with minor amounts of chlorite, muscovite, calcite and feldspar which are considered quartz sand mature. Its origin is related to the source area and rework of soils and sediments of the floodplain. The clay fraction is characterized by the presence of 13 mineral crystalline phases consisting mainly of quartz, muscovite and chlorite, and clay minerals such as kaolinite, vermiculite, montmorillonite and nontronita. Its detrital origin may be due to mineral neoformation and inheritance. Therefore both mineral fractions consist mainly of quartz and kaolinite, which are essential components of the source area as well as the Quaternary alluvial deposits and the soils that make up the region.

Industrial types of uranium deposits in Kazakhstan

International Nuclear Information System (INIS)

Fyodorov, G.V.

2001-01-01

The main industrial uranium deposits of Kazakhstan that can be commercially mined, are located in two ore regions and are represented by two types of the uranium deposits. The first region is named Chu-Syrdarya (75.6% of total resources of Kazakhstan) and is located in the South of Kazakhstan and this one is the largest in the world among the regions of the deposits connected with the bed oxidation zone, localized in the permeable sediments and amenable for in-situ leach mining. The second region is named Kokshetau (16% of total resources) and is located in the North of Kazakhstan at the north edge of Kazak Shield and is characterized by the vein-stockwork type of deposit. Other industrial deposits (8.4% of total resources) are grouped in two regions that have been determined and are retained as reserves for economical and ecological reasons. These are: Pricaspian region with the organic phosphate type of uranium deposits; and Ili-Balkhash region with mainly the coal-uranium type. There are 44 industrial uranium deposits with resources ranging from 1000 t to 100000 t U and more in each of them, in all, in Kazakhstan. Seven of them are completely mined now. Total uranium resources in Kazakhstan are determined at 1670000 t U. (author)

Nuclear imaging of amyloid deposits based upon thioflavins

International Nuclear Information System (INIS)

Wang Yanming; Wu Chunying; Wei Jinjun

2005-01-01

Alzheimer's Disease (AD) is a chronic neurodegenerative disorders characterized by the presence of amyloid deposits and neurofibrillar tangles in the brain. Direct assessment of local changes of amyloid deposits in vivo would greatly facilitate the diagnosis and therapeutic treatments of AD. The goal of this study is to develop small-molecule probes that can be used to follow amyloid deposition in vivo in patients with neurodegenerative diseases. Over the past years, we set out to develop a series of small molecules based on thioflavins as radiotracers for use in nuclear imaging modalities such as positron emission tomography and single photon emission computed tomography. The potential of these amyloid-imaging agents for in vivo studies of amyloid deposition has been evaluated based on the following methods: 1) spectrophotometric binding. assays with synthetic amyloid-β (Aβ) fibrils and AD brain homogenates; 2) fluorescent staining of brain tissue sections to evaluate specificity of binding to amyloid deposits; 3) fluorescent microscopy in mouse models to determine the brain permeability and characterize the binding specificity in vivo, and 4) PET studies in human subjects diagnosed with AD and age-matched control subjects. To date, we have identified some lead compounds as molecular probes with specificity towards amyloid deposits. The in vitro and in vivo binding properties of these compounds have been demonstrated in the following ways: 1) they selectively binds to Aβ fibrils; 2) they selectively stains amyloid deposits in AD brain tissue sections; 3) they readily penetrates the blood-brain barrier, selectively detects amyloid deposits in vivo iri living mice; and 4) One of these compounds, termed PIB, has been successfully used in PET studies in human subjects. In conclusion, amyloid-imaging probes have been developed that could be used to monitor amyloid load in vivo. Applications of the probes are under investigation for potential pathophysiology studies

Tuning the mechanical properties of vertical graphene sheets through atomic layer deposition

International Nuclear Information System (INIS)

Davami, Keivan; Jiang, Yijie; Cortes, John; Lin, Chen; Turner, Kevin T; Bargatin, Igor; Shaygan, Mehrdad

2016-01-01

We report the fabrication and characterization of graphene nanostructures with mechanical properties that are tuned by conformal deposition of alumina. Vertical graphene (VG) sheets, also called carbon nanowalls (CNWs), were grown on copper foil substrates using a radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) technique and conformally coated with different thicknesses of alumina (Al_2O_3) using atomic layer deposition (ALD). Nanoindentation was used to characterize the mechanical properties of pristine and alumina-coated VG sheets. Results show a significant increase in the effective Young’s modulus of the VG sheets with increasing thickness of deposited alumina. Deposition of only a 5 nm thick alumina layer on the VG sheets nearly triples the effective Young’s modulus of the VG structures. Both energy absorption and strain recovery were lower in VG sheets coated with alumina than in pure VG sheets (for the same peak force). This may be attributed to the increase in bending stiffness of the VG sheets and the creation of connections between the sheets after ALD deposition. These results demonstrate that the mechanical properties of VG sheets can be tuned over a wide range through conformal atomic layer deposition, facilitating the use of VG sheets in applications where specific mechanical properties are needed. (paper)

A review of unconformity-type uranium deposits

International Nuclear Information System (INIS)

Dabrowski, F.A.

1980-01-01

Intense interest in uranium in the past decade has led to the discovery of new kinds of deposits of which the so-called unconformity-type are economically the most important. Presently known occurrences are restricted to Australia and Canada where they are characterized chiefly by their spatial relationship to Lower-Middle Proterozoic unconformities. Other common features include similar host-rock assemblages, structural controls, alteration, mineralogy, age relationships and fluid-inclusion data. Similar characteristics in other vein-type deposits, including those of the Beaverlodge district in Canada, deposits in France and Portugal, and the Schwartzwalder mine in the United States, suggest that they may also be of the unconformity-type. Various interpretations of the geological relationships of unconformity-type deposits have resulted in a number of genetic hypotheses, which require different exploration philosophies. Near-surface supergene processes are considered to be most important although other mechanisms may have played contributing roles in the concentration of uranium. There is considerable potential for further discoveries of unconformity-type uranium deposits throughout the world. No such deposits are yet known in southern Africa although several favourable Precambrian unconformities are present

Characterization of Platinum Nanoparticles Deposited on Functionalized Graphene Sheets

Directory of Open Access Journals (Sweden)

Yu-Chun Chiang

2015-09-01

Full Text Available Due to its special electronic and ballistic transport properties, graphene has attracted much interest from researchers. In this study, platinum (Pt nanoparticles were deposited on oxidized graphene sheets (cG. The graphene sheets were applied to overcome the corrosion problems of carbon black at operating conditions of proton exchange membrane fuel cells. To enhance the interfacial interactions between the graphene sheets and the Pt nanoparticles, the oxygen-containing functional groups were introduced onto the surface of graphene sheets. The results showed the Pt nanoparticles were uniformly dispersed on the surface of graphene sheets with a mean Pt particle size of 2.08 nm. The Pt nanoparticles deposited on graphene sheets exhibited better crystallinity and higher oxygen resistance. The metal Pt was the predominant Pt chemical state on Pt/cG (60.4%. The results from the cyclic voltammetry analysis showed the value of the electrochemical surface area (ECSA was 88 m2/g (Pt/cG, much higher than that of Pt/C (46 m2/g. The long-term test illustrated the degradation in ECSA exhibited the order of Pt/C (33% > Pt/cG (7%. The values of the utilization efficiency were calculated to be 64% for Pt/cG and 32% for Pt/C.

Characterization of an innovative method for RuO2 deposition using Electron Microscopy

DEFF Research Database (Denmark)

Cavalca, Filippo

Many photocatalysts work better or exclusively when a suitable cocatalyst, such as RuO2, is deposited on their surface. An innovative method of RuO2 deposition has been found to improve the performance of photocatalysts such as (Ga1-xZnx)(N1-xOx), WO3, SrTiO3 and TiO2. Here we use high angle annu...

Shallow marine event sedimentation in a volcanic arc-related setting: The Ordovician Suri Formation, Famatina range, northwest Argentina

Science.gov (United States)

Mangano, M.G.; Buatois, L.A.

1996-01-01

The Loma del Kilome??tro Member of the Lower Ordovician Suri Formation records arc-related shelf sedimentation in the Famatina Basin of northwest Argentina. Nine facies, grouped into three facies assemblages, are recognized. Facies assemblage 1 [massive and parallel-laminated mudstones (facies A) locally punctuated by normally graded or parallel-laminated silty sandstones (facies B] records deposition from suspension fall-out and episodic storm-induced turbidity currents in an outer shelf setting. Facies assemblage 2 [massive and parallel-laminated mudstones (facies A) interbedded with rippled-top very fine-grained sandstones (facies D)] is interpreted as the product of background sedimentation alternating with distal storm events in a middle shelf environment. Facies assemblage 3 [normally graded coarse to fine-grained sandstones (facies C); parallel-laminated to low angle cross-stratified sandstones (facies E); hummocky cross-stratified sandstones and siltstones (facies F); interstratified fine-grained sandstones and mudstones (facies G); massive muddy siltstones and sandstones (facies H); tuffaceous sandstones (facies I); and interbedded thin units of massive and parallel-laminated mudstones (facies A)] is thought to represent volcaniclastic mass flow and storm deposition coupled with subordinated suspension fall-out in an inner-shelf to lower-shoreface setting. The Loma del Kilo??metro Member records regressive-transgressive sedimentation in a storm- and mass flow-dominated high-gradient shelf. Volcano-tectonic activity was the important control on shelf morphology, while relative sea-level change influenced sedimentation. The lower part of the succession is attributed to mud blanketing during high stand and volcanic quiescence. Progradation of the inner shelf to lower shoreface facies assemblage in the middle part represents an abrupt basinward shoreline migration. An erosive-based, non-volcaniclastic, turbidite unit at the base of this package suggests a sea

A discrete element based simulation framework to investigate particulate spray deposition processes

KAUST Repository

Mukherjee, Debanjan

2015-06-01

© 2015 Elsevier Inc. This work presents a computer simulation framework based on discrete element method to analyze manufacturing processes that comprise a loosely flowing stream of particles in a carrier fluid being deposited on a target surface. The individual particulate dynamics under the combined action of particle collisions, fluid-particle interactions, particle-surface contact and adhesive interactions is simulated, and aggregated to obtain global system behavior. A model for deposition which incorporates the effect of surface energy, impact velocity and particle size, is developed. The fluid-particle interaction is modeled using appropriate spray nozzle gas velocity distributions and a one-way coupling between the phases. It is found that the particle response times and the release velocity distribution of particles have a combined effect on inter-particle collisions during the flow along the spray. It is also found that resolution of the particulate collisions close to the target surface plays an important role in characterizing the trends in the deposit pattern. Analysis of the deposit pattern using metrics defined from the particle distribution on the target surface is provided to characterize the deposition efficiency, deposit size, and scatter due to collisions.

Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

KAUST Repository

Alaie, Seyedhamidreza

2015-02-04

Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties. In this work, Pt deposited by FIB is characterized thermally, structurally, and chemically. Its thermal conductivity is found to be substantially lower than the bulk value of Pt, 7.2 W m-1 K-1 versus 71.6 W m-1 K-1 at room temperature. The low thermal conductivity is attributed to the nanostructure of the material and its chemical composition. Pt deposited by FIB is shown, via aberration corrected TEM, to be a segregated mix of nanocrystalline Pt and amorphous C with Ga and O impurities. Ga impurities mainly reside in the Pt while O is homogeneously distributed throughout. The Ga impurity, small grain size of the Pt, and the amorphous carbon between grains are the cause for the low thermal conductivity of this material. Since Pt deposited by FIB is a common material for affixing samples, this information can be used to assess systematic errors in thermal characterization of different nanosamples. This application is also demonstrated by thermal characterization of two carbon nanofibers and a correction using the reported thermal properties of the Pt deposited by FIB.

Characterization and quantification of deposits build up and removal in straw suspension fired boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt; Shafique Bashir, Muhammad; Wedel, Stig

This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed by condu......This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed...... by conducting advanced probe measurements at the Amagerværkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues......: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established...

Characterization of new a-Si:H detectors fabricated from amorphous silicon deposited at high rate by helium enhanced PECVD

International Nuclear Information System (INIS)

Pochet, T.; Ilie, A.; Foulon, F.

1993-01-01

This paper is concerned with the characterization of new detectors fabricated from a-Si:H films deposited at high rates through the dilution of SiH 4 in helium. Rates of up to ten times (5.5 micrometer/h) that of the standard technique are obtained, allowing for the feasible fabrication of detectors having thickness up to 100 micrometers. The electrical characteristics (depletion voltage, residual space charge density) of the helium diluted material, have been investigated and compared to that of the standard material. The response of detectors, made from both materials, to 5.5 MeV alpha particles are compared. 6 figs., 5 tabs., 13 refs

Chemical vapor deposition of Si/SiC nano-multilayer thin films

International Nuclear Information System (INIS)

Weber, A.; Remfort, R.; Woehrl, N.; Assenmacher, W.; Schulz, S.

2015-01-01

Stoichiometric SiC films were deposited with the commercially available single source precursor Et_3SiH by classical thermal chemical vapor deposition (CVD) as well as plasma-enhanced CVD at low temperatures in the absence of any other reactive gases. Temperature-variable deposition studies revealed that polycrystalline films containing different SiC polytypes with a Si to carbon ratio of close to 1:1 are formed at 1000 °C in thermal CVD process and below 100 °C in the plasma-enhanced CVD process. The plasma enhanced CVD process enables the reduction of residual stress in the deposited films and offers the deposition on temperature sensitive substrates in the future. In both deposition processes the film thickness can be controlled by variation of the process parameters such as the substrate temperature and the deposition time. The resulting material films were characterized with respect to their chemical composition and their crystallinity using scanning electron microscope, energy dispersive X-ray spectroscopy (XRD), atomic force microscopy, X-ray diffraction, grazing incidence X-ray diffraction, secondary ion mass spectrometry and Raman spectroscopy. Finally, Si/SiC multilayers of up to 10 individual layers of equal thickness (about 450 nm) were deposited at 1000 °C using Et_3SiH and SiH_4. The resulting multilayers features amorphous SiC films alternating with Si films, which feature larger crystals up to 300 nm size as measured by transmission electron microscopy as well as by XRD. XRD features three distinct peaks for Si(111), Si(220) and Si(311). - Highlights: • Stoichiometric silicon carbide films were deposited from a single source precursor. • Thermal as well as plasma-enhanced chemical vapor deposition was used. • Films morphology, crystallinity and chemical composition were characterized. • Silicon/silicon carbide multilayers of up to 10 individual nano-layers were deposited.

Aeromagnetic expression of rare earth element (REE) deposits in New Mexico, USA

Science.gov (United States)

Li, M.

2016-12-01

With the development of high-tech devices and the expanding demands in industrial production, rare earth elements(REE) has been playing an increasingly important role in the global economy in the past several decades. Different types of REE serve irreplaceable functions in high-tech industry, as well as for developing sustainable energy and catalysis of manufacturing. Given that the global supply of REE has become strained since 2009 and no known substitutes for REE have been found, exploration for new REE deposits is imperative for economic sustainability. Ten main regions have REE deposits in New Mexico, some of which have not been exploited, while some sites such as Gallinas mountains vein deposits are in early exploration stage. Exploration for the reserves and quantization of mineral compositions of New Mexico's REE depositional districts can have economic benefits in general. In this study, high-resolution airborne magnetic and gravity data were used for studying the Gallinas mountains REE deposit. The purposes of this study are to: (1) characterize specific aeromagnetic anomaly and gravity features from the REE deposits, and (2) apply the characterized features to suggest other areas among the ten REE depositional regions for further exploration. All REE deposits in the study area are found associated with alkaline to alkali-calcic volcanic rocks. A quantitative modeling based on aeromagnetic and gravity anomaly mapping was constructed with an assumption of three units: carbonatites, alkaline volcanic intrusions and REE-concentrated minerals (barite, bastnaesite, etc.). The results of this study show that alkaline deposit is characterized by negative magnetic anomalies and carbonatite is associated with gravity anomaly and vertical gravity gradient high. The area with significantly high aeromagnetic anomaly area and also gravity anomaly high supposed to reflect REE-concentrated minerals such as bastnaesite. For further research, hyperspectral information and

Effect of deposition temperature on the structural, morphological and optical band gap of lead selenide thin films synthesized by chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Hone, Fekadu Gashaw, E-mail: fekeye@gmail.com [Hawassa University, Department of Physics, Hawassa (Ethiopia); Ampong, Francis Kofi [Kwame Nkrumah University of Science and Technology, Department of Physics, Kumasi (Ghana)

2016-11-01

Lead selenide (PbSe) nanocrystalline thin films have been deposited on silica glass substrates by the chemical bath deposition technique. The samples were deposited at the bath temperatures of 60, 75 and 90 °C respectively and characterized by a variety of techniques. The XRD results revealed that the PbSe thin film deposited at 60 °C was amorphous in nature. Films deposited at higher temperatures exhibited sharp and intense diffraction peaks, indicating an improvement in crystallinety. The deposition temperature also had a strong influence on the preferred orientation of the crystallites as well as other structural parameters such as microstrain and dislocation density. From the SEM study it was observed that film deposited at 90 °C had well defined crystallites, uniformly distributed over the entire surface of the substrate. The EDAX study confirmed that the samples deposited at the higher temperature had a better stoichiometric ratio. The optical band gap varied from 2.26 eV to 1.13 eV with increasing deposition temperature. - Highlights: • The crystallinety of the films improved as the deposition temperature increased. • The deposition temperature strongly influenced the preferred orientations. • Microstrain and dislocation density are decreased linearly with deposition temperature. • Band gap decreased from 2.26 eV to 1.13 eV as the deposition temperature increased.

Hydrogeology of exogenic epigenic uranium deposits (sedimentary type) in Uzbekistan

International Nuclear Information System (INIS)

Irgashev, Yu.I.; Gavrilov, V.A.; Muslimov, B.A.

1996-01-01

Common problems of hydrogeology and geotechnology for uranium deposits (sedimentary type) in the Republic of Uzbekistan are discussed in the paper. Hydrogeology includes studies of texture of water-bearing horizons, occurrences of ore bodies in horizons, hydrochemical survey, hydrodynamics and engineering geology. Features of deposits workable by underground leaching are presented. Such terms as 'water-bearing horizon', 'efficiency', 'water-bearing bed' are explained accounting the results of 30 year investigations conducted during prospecting, designing and exploitation of uranium deposits. Stages of hydrogeological survey are listed and features of each of them are described. Importance of geotechnology for a deposit characterization is shown. (author). 6 refs.; 1 fig.; 1 tab

Nanostructured titanium/diamond-like carbon multilayer films: deposition, characterization, and applications.

Science.gov (United States)

Dwivedi, Neeraj; Kumar, Sushil; Malik, Hitendra K

2011-11-01

Titanium/diamond-like carbon multilayer (TDML) films were deposited using a hybrid system combining radio frequency (RF)-sputtering and RF-plasma enhanced chemical vapor deposition (PECVD) techniques under a varied number of Ti/diamond-like carbon (DLC) bilayers from 1 to 4, at high base pressure of 1 × 10(-3) Torr. The multilayer approach was used to create unique structures such as nanospheres and nanorods in TDML films, which is confirmed by scanning electron microscopy (SEM) analysis and explained by a hypothetical model. Surface composition was evaluated by X-ray photoelectron spectroscopy (XPS), whereas energy dispersive X-ray analysis (EDAX) and time-of-flight secondary ion mass spectrometer (ToF-SIMS) measurements were performed to investigate the bulk composition. X-ray diffraction (XRD) was used to evaluate the phase and crystallinity of the deposited TDML films. Residual stress in these films was found to be significantly low. These TDML films were found to have excellent nanomechanical properties with maximum hardness of 41.2 GPa. In addition, various nanomechanical parameters were calculated and correlated with each other. Owing to metallic interfacial layer of Ti in multilayer films, the optical properties, electrical properties, and photoluminescence were improved significantly. Due to versatile nanomechanical properties and biocompatibility of DLC and DLC based films, these TDML films may also find applications in biomedical science.

Atmospheric Deposition: Sampling Procedures, Analytical Methods, and Main Recent Findings from the Scientific Literature

Directory of Open Access Journals (Sweden)

M. Amodio

2014-01-01

Full Text Available The atmosphere is a carrier on which some natural and anthropogenic organic and inorganic chemicals are transported, and the wet and dry deposition events are the most important processes that remove those chemicals, depositing it on soil and water. A wide variety of different collectors were tested to evaluate site-specificity, seasonality and daily variability of settleable particle concentrations. Deposition fluxes of POPs showed spatial and seasonal variations, diagnostic ratios of PAHs on deposited particles, allowed the discrimination between pyrolytic or petrogenic sources. Congener pattern analysis and bulk deposition fluxes in rural sites confirmed long-range atmospheric transport of PCDDs/Fs. More and more sophisticated and newly designed deposition samplers have being used for characterization of deposited mercury, demonstrating the importance of rain scavenging and the relatively higher magnitude of Hg deposition from Chinese anthropogenic sources. Recently biological monitors demonstrated that PAH concentrations in lichens were comparable with concentrations measured in a conventional active sampler in an outdoor environment. In this review the authors explore the methodological approaches used for the assessment of atmospheric deposition, from the analysis of the sampling methods, the analytical procedures for chemical characterization of pollutants and the main results from the scientific literature.

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

Energy Technology Data Exchange (ETDEWEB)

Gonzales, Patricia; Felix, Omar [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Alexander, Caitlin; Lutz, Eric [Division of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1656 E. Mabel St., Tucson, AZ 85724 (United States); Ela, Wendell [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Eduardo Sáez, A., E-mail: esaez@arizona.edu [Department of Chemical and Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States)

2014-09-15

Highlights: • A laboratory dust fractionator was developed for the production of respirable dust. • The size-dependent distribution of arsenic and lead in mine tailings dust is reported. • Metal and metalloid contaminants are enriched in particles smaller than 10 μm. • Lead isotope signatures show spread of mine tailings particles onto surrounding soils. - Abstract: The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of <10 μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure.

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

International Nuclear Information System (INIS)

Gonzales, Patricia; Felix, Omar; Alexander, Caitlin; Lutz, Eric; Ela, Wendell; Eduardo Sáez, A.

2014-01-01

Highlights: • A laboratory dust fractionator was developed for the production of respirable dust. • The size-dependent distribution of arsenic and lead in mine tailings dust is reported. • Metal and metalloid contaminants are enriched in particles smaller than 10 μm. • Lead isotope signatures show spread of mine tailings particles onto surrounding soils. - Abstract: The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of <10 μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure

A combined scanning tunneling microscope-atomic layer deposition tool.

Science.gov (United States)

Mack, James F; Van Stockum, Philip B; Iwadate, Hitoshi; Prinz, Fritz B

2011-12-01

We have built a combined scanning tunneling microscope-atomic layer deposition (STM-ALD) tool that performs in situ imaging of deposition. It operates from room temperature up to 200 °C, and at pressures from 1 × 10(-6) Torr to 1 × 10(-2) Torr. The STM-ALD system has a complete passive vibration isolation system that counteracts both seismic and acoustic excitations. The instrument can be used as an observation tool to monitor the initial growth phases of ALD in situ, as well as a nanofabrication tool by applying an electric field with the tip to laterally pattern deposition. In this paper, we describe the design of the tool and demonstrate its capability for atomic resolution STM imaging, atomic layer deposition, and the combination of the two techniques for in situ characterization of deposition.

RBS characterization of the deposition of very thin SiGe/SiO2 multilayers by LPCVD

International Nuclear Information System (INIS)

Munoz-Martin, A.; Climent-Font, A.; Rodriguez, A.; Sangrador, J.; Rodriguez, T.

2005-01-01

Multilayer structures consisting of several alternated layers of SiGe and SiO 2 with thickness ranging from 2 or Si as well as the deposition of SiO 2 on Si show negligible incubation times. The deposition of SiO 2 on SiGe, however, exhibits an incubation time of several minutes, which would be related to the oxidation of the surface necessary for the SiO 2 deposition to start. In all cases the film thickness increases linearly with deposition time, thus allowing the growth rates to be determined. These data allow the deposition process of these very thin layers to be accurately controlled

Rheological characterization of plasticized corn proteins for fused deposition modeling

Science.gov (United States)

Chaunier, Laurent; Dalgalarrondo, Michèle; Della Valle, Guy; Lourdin, Denis; Marion, Didier; Leroy, Eric

2017-10-01

Additive Manufacturing (AM) of tailored natural biopolymer-based objects by Fused Deposition Modeling (FDM) opens new perspectives for applications such as biomedical temporary devices, or pharmaceutical tablets. This exploits the biocompatibility, resorbability and edibility properties of biopolymers. When adequately plasticized, zeins, storage proteins from endosperm of maize kernels, displayed thermomechanical properties possibly matching FDM processing requirements at a convenient temperature Tprinting=130°C. Indeed, with 20% glycerol added (Tg=42°C), plasticized zeins present a high modulus, E'>1GPa, at ambient conditions, which drops below 0.6 MPa at the processing temperature T=130°C, before flowing in the molten state. The rheological characterization shows that the processing window is limited by a progressive increase of viscosity linked to proteins aggregation and crosslinking by S-S bonding between cysteine amino acid residues, which can lead to gelation. However, for short residence time typical of FDM, the viscosity of plasticized zeins is comparable to the one of standard polymers, like ABS or PLA in their FDM processing conditions: indeed, in presence of glycerol, the molten zeins show a shear-thinning behavior with |η*|≈3kPa.s at 1s-1, decreasing to |η*|≈0.3kPa.s at 100s-1, at 130°C. Moreover, zeins presenting both hydrophilic and hydrophobic domains, amphiphilic plasticizers can be used supplementary to tune their rheological behavior. With 20% oleic acid added to the previous composition, the viscosity is divided down to a ratio about 1/2 at 100s-1 at 130°C, below the value of a standard polymer as PLA at its printing temperature. These results show the possible enhancement of the printability of zein-based materials in the molten state, by combining polar and amphiphilic plasticizers.

Problems related to the determination of mass densities of evaporated reference deposits

International Nuclear Information System (INIS)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Gestel, J. van; Eykens, R.; Gilliam, D.M.; Scott, R.D.; Byrne, J.; Dawber, P.

1991-01-01

The accurate characterization of the surface density (nuclei/cm 2 ) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than ±0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of 6 LiF and 10 B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results. (orig.)

Problems related to the determination of mass densities of evaporated reference deposits

Energy Technology Data Exchange (ETDEWEB)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Gestel, J. van; Eykens, R. (Commission of the European Communities, Joint Research Centre, Central Bureau for Nuclear Measurements, Geel (Belgium)); Gilliam, D.M. (National Inst. of Standards and Tech., Gaithersburg, MD (USA)); Scott, R.D. (Scottish Universities Research and Reactor Centre, Glasgow (UK)); Byrne, J.; Dawber, P. (School of Mathematical and Physical Sciences, Univ. of Sussex, Brighton (UK))

1991-05-15

The accurate characterization of the surface density (nuclei/cm{sup 2}) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than {+-}0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of {sup 6}LiF and {sup 10}B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results. (orig.).

FTIR and electrical characterization of a-Si:H layers deposited by PECVD at different boron ratios

Energy Technology Data Exchange (ETDEWEB)

Orduna-Diaz, A., E-mail: abdu@susu.inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840 (Mexico); Trevino-Palacios, C.G. [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840 (Mexico); Rojas-Lopez, M.; Delgado-Macuil, R.; Gayou, V.L. [Centro de Investigacion en Biotecnologia Aplicada (CIBA), IPN, Tlaxcala, Tlax. 72197 (Mexico); Torres-Jacome, A. [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840 (Mexico)

2010-10-25

Hydrogenated amorphous silicon (a-Si:H) has found applications in flat panel displays, photovoltaic solar cell and recently has been employed in boron doped microbolometer array. We have performed electrical and structural characterizations of a-Si:H layers prepared by plasma enhanced chemical vapor deposition (PECVD) method at 540 K on glass substrates at different diborane (B{sub 2}H{sub 6}) flow ratios (500, 250, 150 and 50 sccm). Fourier transform infrared spectroscopy (FTIR) measurements obtained by specular reflectance sampling mode, show Si-Si, B-O, Si-H, and Si-O vibrational modes (611, 1300, 2100 and 1100 cm{sup -1} respectively) with different strengths which are associated to hydrogen and boron content. The current-voltage curves show that at 250 sccm flow of boron the material shows the lowest resistivity, but for the 150 sccm boron flow it is obtained the highest temperature coefficient of resistance (TCR).

Structure and nanotribology of thermally deposited gold nanoparticles on graphite

Energy Technology Data Exchange (ETDEWEB)

Cihan, Ebru [UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Özoğul, Alper [Department of Mechanical Engineering, Bilkent University, Ankara 06800 (Turkey); Baykara, Mehmet Z., E-mail: mehmet.baykara@bilkent.edu.tr [UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Department of Mechanical Engineering, Bilkent University, Ankara 06800 (Turkey)

2015-11-01

Graphical abstract: - Highlights: • Structure and tribology of thermally deposited AuNPs on HOPG have been studied. • Well-faceted, hexagonal AuNPs are formed on HOPG upon post-deposition annealing. • The crystalline character of the AuNPs is confirmed via TEM measurements. • AFM measurements reveal a “2/3” power law dependence of friction on load on AuNPs. • Friction forces at AuNP edges evolve linearly with increasing height and load. - Abstract: We present experiments involving the structural and frictional characterization of gold nanoparticles (AuNP) thermally deposited on highly oriented pyrolytic graphite (HOPG). The effect of thermal deposition amount, as well as post-deposition annealing on the morphology and distribution of gold on HOPG is studied via scanning electron microscopy (SEM) measurements, while transmission electron microscopy (TEM) is utilized to confirm the crystalline character of the nanoparticles. Lateral force measurements conducted via atomic force microscopy (AFM) under ambient conditions are employed to investigate the nanotribological properties of the gold nanoparticles as a function of normal load. Finally, the increase in lateral force experienced at the edges of the nanoparticles is studied as a function of normal load, as well as nanoparticle height. As a whole, our results constitute a comprehensive structural and frictional characterization of the AuNP/HOPG material system, forming the basis for nanotribology experiments involving the lateral manipulation of thermally deposited AuNPs on HOPG via AFM under ambient conditions.

Structure and nanotribology of thermally deposited gold nanoparticles on graphite

International Nuclear Information System (INIS)

Cihan, Ebru; Özoğul, Alper; Baykara, Mehmet Z.

2015-01-01

Graphical abstract: - Highlights: • Structure and tribology of thermally deposited AuNPs on HOPG have been studied. • Well-faceted, hexagonal AuNPs are formed on HOPG upon post-deposition annealing. • The crystalline character of the AuNPs is confirmed via TEM measurements. • AFM measurements reveal a “2/3” power law dependence of friction on load on AuNPs. • Friction forces at AuNP edges evolve linearly with increasing height and load. - Abstract: We present experiments involving the structural and frictional characterization of gold nanoparticles (AuNP) thermally deposited on highly oriented pyrolytic graphite (HOPG). The effect of thermal deposition amount, as well as post-deposition annealing on the morphology and distribution of gold on HOPG is studied via scanning electron microscopy (SEM) measurements, while transmission electron microscopy (TEM) is utilized to confirm the crystalline character of the nanoparticles. Lateral force measurements conducted via atomic force microscopy (AFM) under ambient conditions are employed to investigate the nanotribological properties of the gold nanoparticles as a function of normal load. Finally, the increase in lateral force experienced at the edges of the nanoparticles is studied as a function of normal load, as well as nanoparticle height. As a whole, our results constitute a comprehensive structural and frictional characterization of the AuNP/HOPG material system, forming the basis for nanotribology experiments involving the lateral manipulation of thermally deposited AuNPs on HOPG via AFM under ambient conditions.

An Alluvial Fan at Apollinaris Patera, Mars

OpenAIRE

Ghail, RC; Hutchison, JE

2003-01-01

Apollinaris Patera, Mars (7?S,173?E), is an intermediate sized volcano (~6 km high, 150 km diameter) with a large (200-km long) fan-like deposit on its southern flank. This fan is deeply incised and originates from a single breach in the rim of the summit caldera. New topographic and multispectral image data reveal that this fan is alluvial, implying a long-lived source of (volcaniclastic) sediment and water (probably from a caldera lake).

Initial deposition and electron paramagnetic resonance defects characterization of TiO{sub 2} films prepared using successive ionic layer adsorption and reaction method

Energy Technology Data Exchange (ETDEWEB)

Wu Yiyong, E-mail: wuyiyong2001@yahoo.com.cn [National Key Laboratory of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, P.O. 432, Nan gang District, Harbin, 150080 (China); Shi Yaping [National Key Laboratory of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, P.O. 432, Nan gang District, Harbin, 150080 (China); Harbin University of Commerce, P.O. 493, Song bei District, Harbin, 150028 (China); Xu Xianbin; Sun Chengyue [National Key Laboratory of Materials Behaviors and Evaluation Technology in Space Environments, Harbin Institute of Technology, P.O. 432, Nan gang District, Harbin, 150080 (China)

2012-06-01

Successive ionic layer adsorption and reaction (SILAR) technique was considered promisingly to deposit ultra thin titanium dioxide (TiO{sub 2}) films under ambient condition. In this paper, the growth process, structures and paramagnetic defects of the films were characterized by complementary techniques of atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and electron paramagnetic resonance spectroscopy. The results indicate that on glass substrate the SILAR TiO{sub 2} film nucleates in an island mode within the initial five deposition cycles but grows in a layer-by-layer mode afterwards. The growth rate was measured as 4.6 A/cycle. In the as-deposited films, a kind of paramagnetic defects is detected at g (2.0029) and it can be attributed to oxygen vacancies. These as-received oxygen vacancies could be annealed out at 473 K. Ultraviolet irradiation on the as-deposited films can also decrease the density of the defects. The relative mechanisms on the phenomenon were discussed in this paper. - Highlights: Black-Right-Pointing-Pointer TiO{sub 2} films are deposited on glass at 25 Degree-Sign C by successive ionic layer adsorption and reaction method with a rate of 4.6 A/cycle. Black-Right-Pointing-Pointer The films nucleate in an island mode initially but grow in a layer mode afterwards. Black-Right-Pointing-Pointer The SILAR TiO{sub 2} films nucleation period is five cycles. Black-Right-Pointing-Pointer Electron paramagnetic resonance spectroscopy shows that TiO{sub 2} films paramagnetic defects are attributed to oxygen vacancies. Black-Right-Pointing-Pointer They will decrease by anneal or ultraviolet radiation and form hydroxyl or superoxide radicals.

Occurrence model for volcanogenic beryllium deposits: Chapter F in Mineral deposit models for resource assessment

Science.gov (United States)

Foley, Nora K.; Hofstra, Albert H.; Lindsey, David A.; Seal, Robert R.; Jaskula, Brian W.; Piatak, Nadine M.

2012-01-01

Current global and domestic mineral resources of beryllium (Be) for industrial uses are dominated by ores produced from deposits of the volcanogenic Be type. Beryllium deposits of this type can form where hydrothermal fluids interact with fluorine and lithophile-element (uranium, thorium, rubidium, lithium, beryllium, cesium, tantalum, rare earth elements, and tin) enriched volcanic rocks that contain a highly reactive lithic component, such as carbonate clasts. Volcanic and hypabyssal high-silica biotite-bearing topaz rhyolite constitutes the most well-recognized igneous suite associated with such Be deposits. The exemplar setting is an extensional tectonic environment, such as that characterized by the Basin and Range Province, where younger topaz-bearing igneous rock sequences overlie older dolomite, quartzite, shale, and limestone sequences. Mined deposits and related mineralized rocks at Spor Mountain, Utah, make up a unique economic deposit of volcanogenic Be having extensive production and proven and probable reserves. Proven reserves in Utah, as reported by the U.S. Geological Survey National Mineral Information Center, total about 15,900 tons of Be that are present in the mineral bertrandite (Be4Si2O7(OH)2). At the type locality for volcanogenic Be, Spor Mountain, the tuffaceous breccias and stratified tuffs that host the Be ore formed as a result of explosive volcanism that brought carbonate and other lithic fragments to the surface through vent structures that cut the underlying dolomitic Paleozoic sedimentary rock sequences. The tuffaceous sediments and lithic clasts are thought to make up phreatomagmatic base surge deposits. Hydrothermal fluids leached Be from volcanic glass in the tuff and redeposited the Be as bertrandite upon reaction of the hydrothermal fluid with carbonate clasts in lithic-rich sections of tuff. The localization of the deposits in tuff above fluorite-mineralized faults in carbonate rocks, together with isotopic evidence for the

Characterization of core/shell structures based on CdTe and GaAs nanocrystalline layers deposited on SnO2 microwires

Science.gov (United States)

Ghimpu, L.; Ursaki, V. V.; Pantazi, A.; Mesterca, R.; Brâncoveanu, O.; Shree, Sindu; Adelung, R.; Tiginyanu, I. M.; Enachescu, M.

2018-04-01

We report the fabrication and characterization of SnO2/CdTe and SnO2/GaAs core/shell microstructures. CdTe or GaAs shell layers were deposited by radio-frequency (RF) magnetron sputtering on core SnO2 microwires synthesized by a flame-based thermal oxidation method. The produced structures were characterized by scanning electron microscopy (SEM), high-resolution scanning transmission electron microscope (HR-STEM), X-ray diffraction (XRD), Raman scattering and FTIR spectroscopy. It was found that the SnO2 core is of the rutile type, while the shells are composed of CdTe or GaAs nanocrystallites of zincblende structure with the dimensions of crystallites in the range of 10-20 nm. The Raman scattering investigations demonstrated that the quality of the porous nanostructured shell is improved by annealing at temperatures of 420-450 °C. The prospects of implementing these microstructures in intrinsic type fiber optic sensors are discussed.

Reactive sputter deposition of boron nitride

International Nuclear Information System (INIS)

Jankowski, A.F.; Hayes, J.P.; McKernan, M.A.; Makowiecki, D.M.

1995-10-01

The preparation of fully dense, boron targets for use in planar magnetron sources has lead to the synthesis of Boron Nitride (BN) films by reactive rf sputtering. The deposition parameters of gas pressure, flow and composition are varied along with substrate temperature and applied bias. The films are characterized for composition using Auger electron spectroscopy, for chemical bonding using Raman spectroscopy and for crystalline structure using transmission electron microscopy. The deposition conditions are established which lead to the growth of crystalline BN phases. In particular, the growth of an adherent cubic BN coating requires 400--500 C substrate heating and an applied -300 V dc bias

Diamond deposition on siliconized stainless steel

International Nuclear Information System (INIS)

Alvarez, F.; Reinoso, M.; Huck, H.; Rosenbusch, M.

2010-01-01

Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp 2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

DEPOSITION AND PROPERTIES OF A LITTLE-ORIENTED PYROLYTIC CARBON; Deposition et proprietes d'un carbone pyrolytique peu oriente

Energy Technology Data Exchange (ETDEWEB)

Rappeneau, J; Bocquet, M; Yvars, M; David, C; Auriol, A

1963-06-15

Pyrolytic carbon obtained by thermal decomposition of acetylene, at partial pressures of 0.02 to 0.1 atm, on walls heated to between 1550 and 1650 deg C, is characterized by its low density (1.35) and a not very marked preferred orientation of the crystallites. The latter property is expressed by an absence of laminar structure in the deposit and by its good compatibility with an artiticial graphite substrate. Following a description of the method of deposition and an outline of the structural properties, certain physical and chemical properties of the substance are examined. (auth)

Ga–Ge–Te amorphous thin films fabricated by pulsed laser deposition

International Nuclear Information System (INIS)

Němec, P.; Nazabal, V.; Dussauze, M.; Ma, H.-L.; Bouyrie, Y.; Zhang, X.-H.

2013-01-01

UV pulsed laser deposition was employed for the fabrication of amorphous Ga–Ge–Te thin films. The local structure of the bulk glasses as well as corresponding thin films was studied using Raman scattering spectroscopy; the main structural motifs were found to be [GeTe 4 ], eventually [GaTe 4 ] corner-sharing tetrahedra and disordered Te chains. Optical functions of the films (refractive index, extinction coefficient) were characterized by variable angle spectroscopic ellipsometry. Photostability experiments showed all Ga–Ge–Te laser deposited films to be stable against 1550 nm laser irradiation in an as-deposited state. In an annealed state, the most photostable composition seems to be Ga 10 Ge 15 Te 75 . This particular composition was further studied from the point of view of thermal stability and stability against ageing in as-deposited state. - Highlights: ► Pulsed laser deposition was used for fabrication of amorphous Ga–Ge–Te thin films. ► GeTe 4 , eventually GaTe 4 tetrahedra and disordered Te chains form the film structure. ► Optical functions of Ge–Ga–Te films were characterized by spectroscopic ellipsometry. ► All as-deposited Ga–Ge–Te thin films are stable against 1550 nm irradiation. ► In annealed state, the most photostable composition seems to be Ga 10 Ge 15 Te 75

Slope-apron deposition in an ordovician arc-related setting: The Vuelta de Las Tolas Member (Suri Formation), Famatina Basin, northwest Argentina

Science.gov (United States)

Mangano, M.G.; Buatois, L.A.

1997-01-01

The Ordovician Suri Formation is part of the infill of the Famatina Basin of northwest Argentina, which formed in an active setting along the western margin of early Paleozoic Gondwana. The lower part of this formation, the Vuelta de Las Tolas Member, records sedimentation on a slope apron formed in an intra-arc basin situated on a flooded continental arc platform. The coincidence of a thick Arenig-Llanvirn sedimentary succession and volcanic-plutonic arc rocks suggests an extensional or transtensional arc setting, and is consistent with evidence of an extensional regime within the volcanic arc in the northern Puna region. The studied stratigraphic sections consist of volcanic rocks and six sedimentary facies. The facies can be clustered into four facies associations. Association 1, composed of facies A (laminated siltstones and mudstones) and B (massive mudstones and siltstones), is interpreted to have accumulated from silty-muddy high-and low-density turbidity currents and highly fluid, silty debris flows, with subsequent reworking by bottom currents, and to a lesser extent, hemipelagic suspension in an open-slope setting. Facies association 2 is dominated by facies C (current-rippled siltstones) strata. These deposits are interpreted to record overbank sedimentation from fine-grained turbidity currents. Facies E (matrix-supported volcanic breccias) interbedded with andesitic lava units comprises facies association 3. Deposition was contemporaneous with subaqueous volcanic activity, and accumulated from cohesive debris flows in a coarse-grained wedge at the base of slope. Facies association 4 is typified by facies D (vitric fine-grained sandstones and siltstones) and F (channelized and graded volcanic conglomerates and breccias) deposits. These strata commonly display thinning-and fining-upward trends, indicating sedimentation from highly-concentrated volcaniclastic turbidity currents in a channelized system. The general characteristics of these deposits of fresh

Chemical characterization of condensates from the Shatlyk deposit

Energy Technology Data Exchange (ETDEWEB)

Khankuliev, K.; Makarov, V.V.; Talalaev, E.I.

1980-01-01

Condensates from the deposits of Eastern and Western Shatlyk differ little in terms of fractional and group hydrocarbon composition. They are all comparatively light, boil away by 350/sup 0/, while the benzene part (60-200/sup 0/) amounts to 43-44% and the kerosene part (200-300/sup 0/), 39-42%. The basic part of the cyclic hydrocarbons (naphthene and aromatic) is concentrated in the light condensate fractions, which boil away by 150/sup 0/. The total content of the aromatic hydrocarbons in the condensates is at most 10%. The 150-200/sup 0/ fractions is 85% paraffin hydrocarbons, while ramified and nonramified structures of paraffin hydrocarbons are found in equal quantities.

Effect of Different Catalyst Deposition Technique on Aligned Multiwalled Carbon Nanotubes Grown by Thermal Chemical Vapor Deposition

Directory of Open Access Journals (Sweden)

Mohamed Shuaib Mohamed Saheed

2014-01-01

Full Text Available The paper reported the investigation of the substrate preparation technique involving deposition of iron catalyst by electron beam evaporation and ferrocene vaporization in order to produce vertically aligned multiwalled carbon nanotubes array needed for fabrication of tailored devices. Prior to the growth at 700°C in ethylene, silicon dioxide coated silicon substrate was prepared by depositing alumina followed by iron using two different methods as described earlier. Characterization analysis revealed that aligned multiwalled carbon nanotubes array of 107.9 µm thickness grown by thermal chemical vapor deposition technique can only be achieved for the sample with iron deposited using ferrocene vaporization. The thick layer of partially oxidized iron film can prevent the deactivation of catalyst and thus is able to sustain the growth. It also increases the rate of permeation of the hydrocarbon gas into the catalyst particles and prevents agglomeration at the growth temperature. Combination of alumina-iron layer provides an efficient growth of high density multiwalled carbon nanotubes array with the steady growth rate of 3.6 µm per minute for the first 12 minutes and dropped by half after 40 minutes. Thicker and uniform iron catalyst film obtained from ferrocene vaporization is attributed to the multidirectional deposition of particles in the gaseous form.

Geology and Ore Deposits of the Uncompahgre (Ouray) Mining District, Southwestern Colorado

Science.gov (United States)

Burbank, Wilbur Swett; Luedke, Robert G.

2008-01-01

Formation, are chiefly tuff breccias of intermediate composition, which were deposited as extensive volcaniclastic aprons around volcanic centers to the east and south of the area. The Ouray area, in general, exhibits the typical effects of a minimum of three major uplifts of the ancestral San Juan Mountains. The earliest of these uplifts, with accompanying deformation and erosion, occurred within the Proterozoic, and the other two occurred at the close, respectively, of the Paleozoic and Mesozoic. The last event, known as the Laramide orogeny, locally was accompanied by extensive intrusion of igneous rocks of dominantly intermediate composition. Domal uplifts of the ancestral mountains resulted in peripheral monoclinal folds, plunging anticlines radial to the central core of the mountain mass, faults, and minor folds. The principal ore deposits of the Uncompahgre district were associated with crosscutting and laccolithic intrusions of porphyritic granodiorite formed during the Laramide (Late Cretaceous to early Tertiary) orogeny. The ores were deposited chiefly in the Paleozoic and Mesozoic sedimentary strata having an aggregate thickness of about 4,500 feet (ft) and occur beneath the early Tertiary unconformity, which in places truncated some of the uppermost deposits. A few ore deposits of late Tertiary age occur also in the sedimentary rocks near the southern margin of the district, but are restricted mostly to the overlying volcanic rocks. Ore deposits in the Uncompahgre district range from low-grade, contact-metamorphic through pyritic base-metal bodies containing silver and gold tellurides and native gold to silver-bearing lead-zinc deposits, and are zoned about the center of intrusive activity, a stock in an area referred to as The Blowout. Ore deposition within the Uncompahgre district was largely controlled by structural trends and axes of uplift established mainly in the late Paleozoic phase of deformation, but also in part by structural lin

Characterization of the electrochemical behavior of coating by steel welding 308l and in presence of noble metals deposits; Caracterizacion del comportamiento electroquimico de recubrimiento por soldadura de acero 308L y en presencia de depositos de metales nobles

Energy Technology Data Exchange (ETDEWEB)

Piedras, P.; Arganis J, C. R., E-mail: pedro.piedras@hotmail.es [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2014-10-15

In this work the oxide deposits and noble metals deposit were characterized (Ag and Pt) on a coating of stainless steel 308l that were deposited by the shield metal arc welding (SMAW) on steel A36 by means of scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. The extrapolation of Tafel technique was also used to obtain the corrosion potential (Ec) for the pre-rusty steel and for the samples with deposits of Pt and Ag under conditions of hydrogen water chemistry (HWC), demonstrating that this parameter diminishes with the presence of this deposits. (Author)

Characterization of ZnO film grown on polycarbonate by atomic layer deposition at low temperature

Energy Technology Data Exchange (ETDEWEB)

Lee, Gyeong Beom; Han, Gwon Deok; Shim, Joon Hyung; Choi, Byoung-Ho, E-mail: bhchoi@korea.ac.kr [School of Mechanical Engineering, Korea University, Seoul 136-707 (Korea, Republic of)

2015-01-15

ZnO is an attractive material for use in various technological products such as phosphors, gas sensors, and transparent conductors. Recently, aluminum-doped zinc oxide has received attention as a potential replacement for indium tin oxide, which is one of the transparent conductive oxides used in flat panel displays, organic light-emitting diodes, and organic solar cells. In this study, the characteristics of ZnO films deposited on polycarbonate (PC) substrates by atomic layer deposition (ALD) are investigated for various process temperatures. The growth mechanism of these films was investigated at low process temperatures using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). XRD and XPS were used to determine the preferred orientation and chemical composition of the films, respectively. Furthermore, the difference of the deposition mechanisms on an amorphous organic material, i.e., PC substrate and an inorganic material such as silicon was discussed from the viewpoint of the diffusion and deposition of precursors. The structure of the films was also investigated by chemical analysis in order to determine the effect of growth temperature on the films deposited by ALD.

Deposition of titanium nitride on Si(1 0 0) wafers using plasma focus

International Nuclear Information System (INIS)

Hussain, Tousif; Ahmad, R.; Khan, I.A.; Siddiqui, Jamil; Khalid, Nida; Bhatti, Arshad Saleem; Naseem, Shahzad

2009-01-01

Titanium nitride thin films were deposited on Si(1 0 0) substrates by using a low energy (2.3 KJ) Mather-type plasma focus device. The composition of the deposited films was characterized by X-ray diffraction (XRD). The crystallite size has strong dependence on the numbers of focus shots. The crystallinity of TiN thin films is found to increase with increasing the number of focus shots. The effect of different number of focus shots on micro structural changes of thin films was characterized by Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM). SEM results showed net-like structure for film deposited for 15 numbers of shots, which are elongated grains of Si 3 N 4 in amorphous form embedded into TiN crystals. The average surface roughness was calculated from AFM images of the thin films. These results indicated that the average surface roughness increased for films deposited with increased number of focus shots. The least crystallite size and roughness are observed for film deposited with 25 focus shots.

Growth and characterization of ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films deposited by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Birjega, R. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Vlad, A., E-mail: angela.vlad@gmail.com [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Matei, A.; Ion, V.; Luculescu, C.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Zavoianu, R. [University of Bucharest, Faculty of Chemistry, Department of Chemical Technology and Catalysis, 4-12 Regina Elisabeta Bd., Bucharest (Romania)

2016-09-01

Layered double hydroxides (LDHs) are a class of layered materials consisting of positively charged brucite-like layers and exchangeable interlayer anions. Layered double hydroxides containing a transition metal which undergoes a reversible redox reaction in the useful potential range have been proposed as electrode coating materials due to their properties of charge transport and redox catalysts in basic solutions. Ni–Al,(Ni,Mg)–Al and, as reference, non-electronically conductive Mg–Al double hydroxides thin films were obtained via pulsed laser deposition technique. The thin films were deposited on different substrates (Si, glass) by using a Nd:YAG laser (1064 nm) working at a repetition rate of 10 Hz. X-ray diffraction, Atomic Force Microscopy, Energy Dispersive X-ray spectroscopy, Fourier Transform Infra-Red Spectroscopy, Secondary Ions Mass Spectrometry, Impedance Analyzer and ellipsometry were the techniques used for the as deposited thin films investigation. The optical properties of Ni based LDH thin films and the effect of the Ni amount on the structural, morphological and optical response are evidenced. The optical band gap values, covering a domain between 3.84 eV and 4.38 eV, respond to the Ni overall concentration: the higher Ni amount the lower the band gap value. - Highlights: • Ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films were deposited. • The effect of the nickel is evidenced. • The possibility to tailor the materials accompanied by an optical response is shown.

Metalliferous sediment and a silica-hematite deposit within the Blanco fracture zone, Northeast Pacific

Science.gov (United States)

Hein, J.R.; Clague, D.A.; Koski, R.A.; Embley, R.W.; Dunham, R.E.

2008-01-01

A Tiburon ROV dive within the East Blanco Depression (EBD) increased the mapped extent of a known hydrothermal field by an order of magnitude. In addition, a unique opal-CT (cristobalite-tridymite)-hematite mound was discovered, and mineralized sediments and rock were collected and analyzed. Silica-hematite mounds have not previously been found on the deep ocean floor. The light-weight rock of the porous mound consists predominantly of opal-CT and hematite filaments, rods, and strands, and averages 77.8% SiO2 and 11.8% Fe2O3. The hematite and opal-CT precipitated from a low-temperature (???115?? C), strongly oxidized, silica- and iron-rich, sulfur-poor hydrothermal fluid; a bacterial mat provided the framework for precipitation. Samples collected from a volcaniclastic rock outcrop consist primarily of quartz with lesser plagioclase, smectite, pyroxene, and sulfides; SiO2 content averages 72.5%. Formation of these quartz-rich samples is best explained by cooling in an up-flow zone of silica-rich hydrothermal fluids within a low permeability system. Opal-A, opal-CT, and quartz mineralization found in different places within the EBD hydrothermal field likely reflects decreasing silica saturation and increasing temperature of the mineralizing fluid with increasing silica crystallinity. Six push cores recovered gravel, coarse sand, and mud mineralized variously by Fe or Mn oxides, silica, and sulfides. Total rare-earth element concentrations are low for both the rock and push core samples. Ce and Eu anomalies reflect high and low temperature hydrothermal components and detrital phases. A remarkable variety of types of mineralization occur within the EBD field, yet a consistent suite of elements is enriched (relative to basalt and unmineralized cores) in all samples analyzed: Ag, Au, S, Mo, Hg, As, Sb, Sr, and U; most samples are also enriched in Cu, Pb, Cd, and Zn. On the basis of these element enrichments, the EBD hydrothermal field might best be described as a base

Characterization of defects in hydrogenated amorphous silicon deposited on different substrates by capacitance techniques

International Nuclear Information System (INIS)

Darwich, R.; Roca i Cabarrocas, P.

2011-01-01

Hydrogenated amorphous silicon (a-Si:H) thin films deposited on crystalline silicon and Corning glass substrate were analyzed using different capacitance techniques. The distribution of localized states and some electronic properties were studied using the temperature, frequency and bias dependence of the Schottky barrier capacitance and deep level transient spectroscopy. Our results show that the distribution of the gap states depends on the type of substrate. We have found that the films deposited on c-Si substrate represent only one positively charged or prerelaxed neutral deep state and one interface state, while the films deposited on glass substrate have one interface state and three types of deep defect states, positively or prerelaxed neutral, neutral and negatively charged.

New geochemical, geochronological and structural constraints on the Ediacaran evolution of the south Sirwa, Agadir-Melloul and Iguerda inliers, Anti-Atlas, Morocco

Science.gov (United States)

Blein, O.; Baudin, T.; Soulaimani, A.; Cocherie, A.; Chèvremont, P.; Admou, H.; Ouanaimi, H.; Hafid, A.; Razin, P.; Bouabdelli, M.; Roger, J.

2014-10-01

Paleoproterozoic metamorphic and igneous rocks, Tonian (?)-lower Cryogenian passive margin sedimentary rocks, Neoproterozoic dolerites, and Upper Ediacaran volcaniclastic, volcanic and pyroclastic rocks are exposed in the Agadir Melloul, Iguerda and the southern edge of the Sirwa inliers. A recent field mapping program of the Ediacaran Ouarzazate Group in these areas allow to distinguish three principal volcanic sequences. The first sequence (Adrar-n-Takoucht Formation) outcrops mainly south of the Sirwa inlier, and is composed of felsic pyroclastic deposits and local basaltic lavas with ages ranging between 572 and 570 Ma. The second sequence (Anammar and Tadoughast formations) occurs primarily in the Agadir Melloul-Jbel Iguiguil inlier. The Anammar Formation contains essentially volcano-detrital sediments, with fine airfall pyroclastic deposits. The Tadoughast Formation is composed of felsic pyroclastic deposits and rhyolitic domes with ages ranging between 567 and 564 Ma. The third sequence (Fajjoud Formation) contains felsic pyroclastic deposits, with an age of 556 Ma, associated with porphyritic basalts. The magmatism of the Ouarzazate Group was not continuous between 572 and 556 Ma, but related to distinct pyroclastic pulses. Geochemical data indicate that the pyroclastic rocks of the Ouarzazate Group have a highly potassic calc-alkaline to shoshonitic affinity. However, the basaltic facies associated with the Adrar-n-Takoucht Formation demonstrate a calc-alkaline affinity whereas those associated with the Fajjoud Formation have a tholeiitic affinity. Rhyolitic domes were derived from hyperaluminous leucogranites. In sum, the typology of zircons defines three poles: (i) subalkaline granites; (ii) calc-alkaline monzogranites and granodiorites frequently associated with basic rocks; and (iii) aluminous leucogranites. In addition, the volcaniclastic deposits of the Ouarzazate Group are submitted to a syn-sedimentary tectonic. The Adrar-n-Takoucht Formation is

Deposition of antimony telluride thin film by ECALE

Institute of Scientific and Technical Information of China (English)

GAO; Xianhui; YANG; Junyou; ZHU; Wen; HOU; Jie; BAO; Siqian; FAN; Xi'an; DUAN; Xingkai

2006-01-01

The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.

Electroless deposition of Ni-P on a silicon surface

Directory of Open Access Journals (Sweden)

hassan El Grini

2017-06-01

Full Text Available The present article concerns the metallization of silicon substrates by deposition of the nickel-phosphorus alloy produced by an autocatalytic chemical process. The deposition electrolyte is composed of a metal salt, a reducing agent (sodium hypophosphite, a complexing agent (sodium citrate and a buffer (ammonium acetate. The deposition could only be carried out after activation of the silicon by fixing catalytic species on its surface. The immersion of the silicon samples in palladium chloride made it possible to produce relatively thick and regular Ni-P coatings. The immersion time was optimized. The activation of Si was characterized by XPS and the Ni-P coating by XPS and M.E.B. The electrochemical study did not show any real mechanism changes compared to the Ni-P deposition on a conductive surface. 

Rapid injection of particles and gas into non-fluidized granular material, and some volcanological implications

Science.gov (United States)

Ross, Pierre-Simon; White, James D. L.; Zimanowski, Bernd; Büttner, Ralf

2008-10-01

In diatremes and other volcanic vents, steep bodies of volcaniclastic material having differing properties (particle size distribution, proportion of lithic fragments, etc.) from those of the surrounding vent-filling volcaniclastic material are often found. It has been proposed that cylindrical or cone-shaped bodies result from the passage of “debris jets” generated after phreatomagmatic explosions or other discrete subterranean bursts. To learn more about such phenomena, we model experimentally the injection of gas-particulate dispersions through other particles. Analogue materials (glass beads or sand) and a finite amount of compressed air are used in the laboratory. The gas is made available by rapidly opening a valve—therefore the injection of gas and coloured particles into a granular host is a brief (non-erupting injections produce cylindrical bodies of coloured beads whereas erupting runs produce flaring upward or conical deposits. Changing the particle size of the host glass beads does not have a large effect under the size range investigated (100 200 to 300 400 μm). Doubling the host thickness (injection depth) requires a doubling of the initial gas pressure to produce similar phenomena. Such injections—whether erupting or wholly subterranean—provide a compelling explanation for the origin and characteristics of multiple cross-cutting bodies that have been documented for diatreme and other vent deposits.

Atmospheric nuclear weapon test history as characterized by the deposition of 14C in human teeth

International Nuclear Information System (INIS)

Nishizawa, K.; Togari, A.; Matsumoto, S.; Nagatsu, T.

1990-01-01

The 14 C concentration in the collagen of human teeth was retrospectively investigated to determine whether its incorporation was related to atmospheric testing of nuclear weapons. Teeth were extracted for dental therapy from July 1987 to February 1988 from patients who were residents in Japan. Tooth collagen was extracted with HCl and converted to amorphous C by heating in a vacuum line. Specimens for 14 C analysis were prepared by mixing the amorphous C with silver powder. The 14 C concentration was measured by mass spectrometer. The 14 C concentration in tooth collagen rapidly increased in 1961 after the bomb tests, peaked around 1967-1968, and then gradually decreased. The collagen of human teeth maintains the 14 C concentration at the age of root completion for life. The results of this study indicate that the history of environmental contamination from atmospheric nuclear weapon's tests has been characterized by deposition of 14 C in the tooth collagen 14 C of human beings

Characterization and gas-sensing behavior of an iron oxide thin film prepared by atomic layer deposition

International Nuclear Information System (INIS)

Aronniemi, Mikko; Saino, J.; Lahtinen, J.

2008-01-01

In this work we investigate an iron oxide thin film grown with atomic layer deposition for a gas sensor application. The objective is to characterize the structural, chemical, and electrical properties of the film, and to demonstrate its gas-sensitivity. The obtained scanning electron microscopy and atomic force microscopy results indicate that the film has a granular structure and that it has grown mainly on the glass substrate leaving the platinum electrodes uncovered. X-ray diffraction results show that iron oxide is in the α-Fe 2 O 3 (hematite) phase. X-ray photoelectron spectra recorded at elevated temperature imply that the surface iron is mainly in the Fe 3+ state and that oxygen has two chemical states: one corresponding to the lattice oxygen and the other to adsorbed oxygen species. Electric conductivity has an activation energy of 0.3-0.5 eV and almost Ohmic current-voltage dependency. When exposed to O 2 and CO, a typical n-type response is observed

High-deposition-rate ceramics synthesis

Energy Technology Data Exchange (ETDEWEB)

Allendorf, M.D.; Osterheld, T.H.; Outka, D.A. [Sandia National Laboratories, Livermore, CA (United States)] [and others

1995-05-01

Parallel experimental and computational investigations are conducted in this project to develop validated numerical models of ceramic synthesis processes. Experiments are conducted in the High-Temperature Materials Synthesis Laboratory in Sandia`s Combustion Research Facility. A high-temperature flow reactor that can accommodate small preforms (1-3 cm diameter) generates conditions under which deposition can be observed, with flexibility to vary both deposition temperature (up to 1500 K) and pressure (as low as 10 torr). Both mass spectrometric and laser diagnostic probes are available to provide measurements of gas-phase compositions. Experiments using surface analytical techniques are also applied to characterize important processes occuring on the deposit surface. Computational tools developed through extensive research in the combustion field are employed to simulate the chemically reacting flows present in typical industrial reactors. These include the CHEMKIN and Surface-CHEMKIN suites of codes, which permit facile development of complex reaction mechanisms and vastly simplify the implementation of multi-component transport and thermodynamics. Quantum chemistry codes are also used to estimate thermodynamic and kinetic data for species and reactions for which this information is unavailable.

Formulation, Characterization and Pulmonary Deposition of Nebulized Celecoxib Encapsulated Nanostructured Lipid Carriers

Science.gov (United States)

Patlolla, Ram R.; Chougule, Mahavir; Patel, Apurva R.; Jackson, Tanise; Tata, Prasad NV; Singh, Mandip

2010-01-01

The aim of the current study was to encapsulate celecoxib (Cxb) in the Nanostructured Lipid Carrier (Cxb-NLC) nanoparticles and evaluate the lung disposition of nanoparticles following nebulization in Balb/c mice. Cxb-NLC nanoparticles were prepared with Cxb, Compritol, Miglyol and sodium taurocholate using high-pressure homogenization. Cxb-NLC nanoparticles were characterized for physical and aerosol properties. In-vitro cytotoxicity studies were performed with A549 cells. The lung deposition and pharmacokinetic parameters of Cxb-NLC and Cxb solution (Cxb-Soln) formulations were determined using Inexpose™ system and Pari LC star jet nebulizer. The particle size and entrapment efficiency of Cxb-NLC formulation were 217 ± 20 nm and > 90%, respectively. The Cxb-NLC released the drug in controlled fashion, and in vitro aersolization of Cxb-NLC formulation showed FPF of 75.6 ± 4.6 %, MMAD of 1.6 ±0.13 μm and GSD of 1.2 ± 0.21. Cxb-NLC showed dose and time dependent cytotoxicity against A549 cells. Nebulization of Cxb-NLC demonstrated 4 fold higher AUCt/D in lung tissues compared to Cxb-Soln. The systemic clearance of Cxb-NLC was slower (0.93 L/h) compared to Cxb-Soln (20.03 L/h). Cxb encapsulated NLC were found to be stable and aerodynamic properties were within the respirable limits. Aerosolization of Cxb-NLC improved the Cxb pulmonary bioavailability compared to solution formulation which will potentially lead to better patient compliance with minimal dosing intervals. PMID:20153385

Ultra-small platinum and gold nanoparticles by arc plasma deposition

International Nuclear Information System (INIS)

Kim, Sang Hoon; Jeong, Young Eun; Ha, Heonphil; Byun, Ji Young; Kim, Young Dok

2014-01-01

Highlights: • Ultra-small (<2 nm) and bigger platinum and gold nanoparticles were produced by arc plasma deposition (APD). • Size and coverage of deposited nanoparticles were easily controlled with APD parameters. • Crystalline structures of deposited nanoparticles emerged only when the particle size was bigger than ∼2 nm. - Abstract: Ultra-small (<2 nm) nanoparticles of platinum and gold were produced by arc plasma deposition (APD) in a systematic way and the deposition behavior was studied. Nanoparticles were deposited on two dimensional amorphous carbon and amorphous titania thin films and characterized by transmission electron microscopy (TEM). Deposition behavior of nanoparticles by APD was studied with discharge voltage (V), discharge condenser capacitance (C), and the number of plasma pulse shots (n) as controllable parameters. The average size of intrinsic nanoparticles generated by APD process was as small as 0.9 nm and deposited nanoparticles began to have crystal structures from the particle size of about 2 nm. V was the most sensitive parameter to control the size and coverage of generated nanoparticles compared to C and n. Size of APD deposited nanoparticles was also influenced by the nature of evaporating materials and substrates

Growth and characterization of polar and nonpolar ZnO film grown on sapphire substrates by using atomic layer deposition

International Nuclear Information System (INIS)

Kim, Ki-Wook; Son, Hyo-Soo; Choi, Nak-Jung; Kim, Jihoon; Lee, Sung-Nam

2013-01-01

We investigated the electrical and the optical properties of polar and nonpolar ZnO films grown on sapphire substrates with different crystallographic planes. High resolution X-ray results revealed that polar c-plane (0001), nonpolar m-plane (10-10) and a-plane (11-20) ZnO thin films were grown on c-plane, m- and r-sapphire substrates by atomic layer deposition, respectively. Compared with the c-plane ZnO film, nonpolar m-plane and a-plane ZnO films showed smaller surface roughness and anisotropic surface structures. Regardless of ZnO crystal planes, room temperature photoluminescence spectra represented two emissions which consisted of the near bandedge (∼ 380 nm) and the deep level emission (∼ 500 nm). The a-plane ZnO films represented better optical and electrical properties than c-plane ZnO, while m-plane ZnO films exhibited poorer optical and electrical properties than c-plane ZnO. - Highlights: • Growth and characterization of a-, c- and m-plane ZnO film by atomic layer deposition. • The a-plane ZnO represented better optical and electrical properties than c-plane ZnO. • The m-plane ZnO exhibited poorer optical and electrical properties than c-plane ZnO

Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

Directory of Open Access Journals (Sweden)

Jose Alberto Alvarado

2015-04-01

Full Text Available This work presents a novel technique to deposit ZnO thin films through a metal vacuum evaporation technique using colloidal nanoparticles (average size of 30 nm, which were synthesized by our research group, as source. These thin films had a thickness between 45 and 123 nm as measured by profilometry. XRD patterns of the deposited thin films were obtained. According to the HRSEM micrographs worm-shaped nanostructures are observed in samples annealed at 600 °C and this characteristic disappears as the annealing temperature increases. The films obtained were annealed from 25 to 1000 °C, showing a gradual increase in transmittance spectra up to 85%. The optical band gaps obtained for these films are about 3.22 eV. The PL measurement shows an emission in the red and in the violet region and there is a correlation with the annealing process.

Characterization of MAPLE deposited WO3 thin films for electrochromic applications

Science.gov (United States)

Boyadjiev, S. I.; Stefan, N.; Szilágyi, I. M.; Mihailescu, N.; Visan, A.; Mihailescu, I. N.; Stan, G. E.; Besleaga, C.; Iliev, M. T.; Gesheva, K. A.

2017-01-01

Tungsten trioxide (WO3) is a widely studied material for electrochromic applications. The structure, morphology and optical properties of WO3 thin films, grown by matrix assisted pulsed laser evaporation (MAPLE) from monoclinic WO3 nano-sized particles, were investigated for their possible application as electrochromic layers. A KrF* excimer (λ=248 nm, ζFWHM=25 ns) laser source was used in all experiments. The MAPLE deposited WO3 thin films were studied by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD) and Fourier transform infrared spectroscopy (FTIR). Cyclic voltammetry measurements were also performed, and the coloring and bleaching were observed. The morpho-structural investigations disclosed the synthesis of single-phase monoclinic WO3 films consisting of crystalline nano-grains embedded in an amorphous matrix. All thin films showed good electrochromic properties, thus validating application of the MAPLE deposition technique for the further development of electrochromic devices.

Characterization of MAPLE deposited WO3 thin films for electrochromic applications

International Nuclear Information System (INIS)

Boyadjiev, S I; Iliev, M T; Stefan, N; Mihailescu, N; Visan, A; Mihailescu, I N; Szilágyi, I M; Stan, G E; Besleaga, C; Gesheva, K A

2017-01-01

Tungsten trioxide (WO 3 ) is a widely studied material for electrochromic applications. The structure, morphology and optical properties of WO 3 thin films, grown by matrix assisted pulsed laser evaporation (MAPLE) from monoclinic WO 3 nano-sized particles, were investigated for their possible application as electrochromic layers. A KrF* excimer (λ=248 nm, ζ FWHM =25 ns) laser source was used in all experiments. The MAPLE deposited WO 3 thin films were studied by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD) and Fourier transform infrared spectroscopy (FTIR). Cyclic voltammetry measurements were also performed, and the coloring and bleaching were observed. The morpho-structural investigations disclosed the synthesis of single-phase monoclinic WO 3 films consisting of crystalline nano-grains embedded in an amorphous matrix. All thin films showed good electrochromic properties, thus validating application of the MAPLE deposition technique for the further development of electrochromic devices. (paper)

Gene expression and morphogenesis during the deposition of Drosophila wing cuticle.

Science.gov (United States)

Adler, Paul N

2017-07-03

The exoskeleton of insects and other arthropods is a very versatile material that is characterized by a complex multilayer structure. In Sobala and Adler (2016) we analyzed the process of wing cuticle deposition by RNAseq and electron microscopy. In this extra view we discuss the unique aspects of the envelope the first and most outermost layer and the gene expression program seen at the end of cuticle deposition. We discussed the role of undulae in the deposition of cuticle and how the hydrophobicity of wing cuticle arises.

Deposition Diagnostics for Next-step Devices

International Nuclear Information System (INIS)

Skinner, C.H.; Roquemore, A.L.; Bader, A.; Wampler, W.R.

2004-01-01

The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX

The Effects of Two Thick Film Deposition Methods on Tin Dioxide Gas Sensor Performance

OpenAIRE

Bakrania, Smitesh D.; Wooldridge, Margaret S.

2009-01-01

This work demonstrates the variability in performance between SnO2 thick film gas sensors prepared using two types of film deposition methods. SnO2 powders were deposited on sensor platforms with and without the use of binders. Three commonly utilized binder recipes were investigated, and a new binder-less deposition procedure was developed and characterized. The binder recipes yielded sensors with poor film uniformity and poor structural integrity, compared to the binder-less deposition meth...

Tungsten deposition by hydrogen-atom reaction with tungsten hexafluoride

International Nuclear Information System (INIS)

Lee, W.W.

1991-01-01

Using gaseous hydrogen atoms with WF 6 , tungsten atoms can be produced in a gas-phase reaction. The atoms then deposit in a near-room temperature process, which results in the formation of tungsten films. The W atoms (10 10 -10 11 /cm 3 ) were measured in situ by atomic absorption spectroscopy during the CVD process. Deposited W films were characterized by Auger electron spectroscopy, Rutherford backscattering, and X-ray diffraction. The surface morphology of the deposited films and filled holes was studied using scanning electron microscopy. The deposited films were highly adherent to different substrates, such as Si, SiO 2 , Ti/Si, TiN/Si and Teflon. The reaction mechanism and kinetics were studied. The experimental results indicated that this method has three advantages compared to conventional CVD or PECVD: (1) film growth occurs at low temperatures; (2) deposition takes place in a plasma-free environment; and (3) a low level of impurities results in high-quality adherent films

The deposition of highly uniform and adhesive nanocrystalline PbS film from solution

International Nuclear Information System (INIS)

Yang Yujun; Hu Shengshui

2008-01-01

Mirror-like PbS films have been deposited by chemical deposition on glass substrates from alkaline chemical bath containing lead nitrate, sodium thiosulfate and 1-thioglycerol, which was used to catalyze the hydrolysis of thiosulfate. Nanostructure characterization was carried out by x-ray diffraction and scanning electron microscopy in order to determine the average crystallite size (61 nm) and study the surface morphologies of the as-deposited films

Electrical characterization of the temperature dependence in CdTe/CdS heterojunctions deposited in-situ by pulsed laser deposition

Science.gov (United States)

Avila-Avendano, Jesus; Quevedo-Lopez, Manuel; Young, Chadwin

2018-02-01

The I-V and C-V characteristics of CdTe/CdS heterojunctions deposited in-situ by Pulsed Laser Deposition (PLD) were evaluated. In-situ deposition enables the study of the CdTe/CdS interface by avoiding potential impurities at the surface and interface as a consequence of exposure to air. The I-V and C-V characteristics of the resulting junctions were obtained at different temperatures, ranging from room temperature to 150 °C, where the saturation current (from 10-8 to 10-4 A/cm2), ideality factor (between 1 and 2), series resistance (from 102 to 105 Ω), built-in potential (0.66-0.7 V), rectification factor (˜106), and carrier concentration (˜1016 cm-3) were obtained. The current-voltage temperature dependence study indicates that thermionic emission is the main transport mechanism at the CdTe/CdS interface. This study also demonstrated that the built-in potential (Vbi) calculated using a thermionic emission model is more accurate than that calculated using C-V extrapolation since C-V plots showed a Vbi shift as a function of frequency. Although CdTe/CdS is widely used for photovoltaic applications, the parameters evaluated in this work indicate that CdTe/CdS heterojunctions could be used as rectifying diodes and junction field effect transistors (JFETs). JFETs require a low PN diode saturation current, as demonstrated for the CdTe/CdS junction studied here.

Pyroclastic eruptions from Axial caldera, Juan de Fuca Ridge, NE Pacific Ocean

Energy Technology Data Exchange (ETDEWEB)

Helo, Christoph; Stix, John [Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7 (Canada); Clague, Dave A [Monterey Bay Aquarium Research Institute 7700 Sandholdt Road, Moss Landing, CA 95039-9644 (United States)

2008-10-01

Unconsolidated volcaniclastic glass deposits on the flanks of Axial Seamount, a caldera system situated on the Juan de Fuca Ridge in the NE Pacific Ocean, demonstrate the occurrence of explosive events, in addition to effusive activity. The variety of produced glass fragments ranges from various angular forms to thin deep-sea limu o Pele, with dominantly moderately fractionated to occasionally primitive MOR basalt composition. A model involving the collapse of a magmatic foam layer may account for the observed spectrum of glass fragments.

Chemical vapor deposition polymerization the growth and properties of parylene thin films

CERN Document Server

Fortin, Jeffrey B

2004-01-01

Chemical Vapor Deposition Polymerization - The Growth and Properties of Parylene Thin Films is intended to be valuable to both users and researchers of parylene thin films. It should be particularly useful for those setting up and characterizing their first research deposition system. It provides a good picture of the deposition process and equipment, as well as information on system-to-system variations that is important to consider when designing a deposition system or making modifications to an existing one. Also included are methods to characterizae a deposition system's pumping properties as well as monitor the deposition process via mass spectrometry. There are many references that will lead the reader to further information on the topic being discussed. This text should serve as a useful reference source and handbook for scientists and engineers interested in depositing high quality parylene thin films.

Microstructural characterization of CPPD and hydroxyapatite crystal depositions on human menisci

Energy Technology Data Exchange (ETDEWEB)

Katsamenis, Orestis L. [Bioengineering Research Group, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Department of Materials Science, University of Patras, 26504 Rio, Patras (Greece); Karoutsos, Vagelis [Department of Materials Science, University of Patras, 26504 Rio, Patras (Greece); Kontostanos, Konstantinos; Panagiotopoulos, Elias C. [Department of Orthopaedics, School of Medicine, University of Patras, 26500 Rio, Patras (Greece); Papadaki, Helen [Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, 26500 Rio, Patras (Greece); Bouropoulos, Nikolaos [Department of Materials Science, University of Patras, 26504 Rio, Patras (Greece); Foundation for Research and Technology, Hellas-Institute of Chemical Engineering and High Temperature Chemical Processes - FORTH/ICE-HT, P.O. Box 1414, GR-26504 Patras (Greece)

2012-11-15

Meniscus is a fibrocartilaginous tissue composed mainly of water and a dense elaborate collagen network with a predominantly circumferential alignment. Crystal formation and accumulation on meniscal tissue is frequently observed especially in elderly. In this study, we used X-ray diffraction (XRD), FTIR and FT-Raman for the structural identification of the depositions and Optical microscopy, Scanning Electron microscopy (SEM/EDX) and Atomic Force microscopy (AFM), in order to investigate the structural relationship between the crystal deposits and the collagen fibers of human meniscal tissues. We are reporting on the formation of intercalary ''colonies'' of Calcium Pyrophosphate Dihydrate (CPPD) crystals with two distinct morphologies corresponding to the monoclinic and the triclinic phase, as well as the formation of micro-aggregations composed of nano-crystalline HAP aggregations which are developed along the longitudinal axis of collagen fibers without extensively disturbing the collagens arrangement. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Characterization and dating of coastal deposits of NW Portugal (Minho-Neiva area): A record of climate, eustasy and crustal uplift during the Quaternary

DEFF Research Database (Denmark)

Carvalhido, Ricardo P.; Pereira, Diamantino I.; Cunha, Pedro P.

2014-01-01

This study presents the characterization and numerical dating of Quaternary coastal deposits of NW Portugal, located between the mouths of the Minho and Neiva rivers. They record continental (small alluvial fans and streams) and transitional (aeolian dunes, interdune ponds, estuary, sandy...... and gravelly beaches) paleoenvironments. Quartz and K-feldspar optically stimulated luminescence (OSL) dating is employed as well as AMS C-14 dating. A staircase of coastal terraces (abrasion shore platforms) was identified (altimetry, a.s.l.) and ascribed to the following probable Marine Isotope Stages (MIS...

Characterizations of wet mercury deposition on a remote high-elevation site in the southeastern Tibetan Plateau

International Nuclear Information System (INIS)

Huang, Jie; Kang, Shichang; Zhang, Qianggong; Guo, Junming; Sillanpää, Mika; Wang, Yongjie; Sun, Shiwei

2015-01-01

Accurate measurements of wet mercury (Hg) deposition are critically important for the assessment of ecological responses to pollutant loading. The Hg in wet deposition was measured over a 3-year period in the southeastern Tibetan Plateau. The volume-weighted mean (VWM) total Hg (Hg_T) concentration was somewhat lower than those reported in other regions of the Tibetan Plateau, but the VWM methyl-Hg concentration and deposition flux were among the highest globally reported values. The VWM Hg_T concentration was higher in non-monsoon season than in monsoon season, and wet Hg_T deposition was dominated by the precipitation amount rather than the scavenging of atmospheric Hg by precipitation. The dominant Hg species in precipitation was mainly in the form of dissolved Hg, which indicates the pivotal role of reactive gaseous Hg within-cloud scavenging to wet Hg deposition. Moreover, an increasing trend in precipitation Hg concentrations was synchronous with the recent economic development in South Asia. - Highlights: • The lowest Hg_T concentration in precipitation was found at Southeast Tibet Station. • MeHg concentration and wet deposition flux were among the highest at our study site. • Hg_D dominated the concentration and flux of Hg_T in wet Hg deposition. • A long-term increasing trend in the Hg_T concentration was found at our study site. - An increasing trend in the precipitation Hg concentrations was synchronous with the recent economic development in South Asia.

Characterization of particulate matter deposited on urban tree foliage: A landscape analysis approach

Science.gov (United States)

Lin, Lin; Yan, Jingli; Ma, Keming; Zhou, Weiqi; Chen, Guojian; Tang, Rongli; Zhang, Yuxin

2017-12-01

Plants can mitigate ambient particulate matter by cleaning the air, which is crucial to urban environments. A novel approach was presented to quantitatively characterize particulate matter deposited on urban tree foliage. This approach could accurately quantify the number, size, shape, and spatial distribution of particles with different diameters on leaves. Spatial distribution is represented by proximity, which measures the closeness of particles. We sampled three common broadleaf species and obtained images through field emission scanning electron microscopy. We conducted the object-based method to extract particles from images. We then used Fragstats to analyze the landscape characteristics of these particles in term of selected metrics. Results reveal that Salix matsudana is more efficient than Ailanthus altissima and Fraxinus chinensis in terms of the number and area of particles per unit area and the proportion of fine particulate matter. The shape complexity of the particles increases with their size. Among the three species, S. matsudana and A. altissima particles respectively yield the highest and lowest proximity. PM1 in A. altissima and PM10 in F. chinensis and S. matsudana show the highest proximity, which may influence subsequent particle retention. S. matsudana should be generally considered to collect additional small particles. Different species and particle sizes exhibit various proximities, which should be further examined to elucidate the underlying mechanism.

Characterizations of wet mercury deposition on a remote high-elevation site in the southeastern Tibetan Plateau.

Science.gov (United States)

Huang, Jie; Kang, Shichang; Zhang, Qianggong; Guo, Junming; Sillanpää, Mika; Wang, Yongjie; Sun, Shiwei; Sun, Xuejun; Tripathee, Lekhendra

2015-11-01

Accurate measurements of wet mercury (Hg) deposition are critically important for the assessment of ecological responses to pollutant loading. The Hg in wet deposition was measured over a 3-year period in the southeastern Tibetan Plateau. The volume-weighted mean (VWM) total Hg (HgT) concentration was somewhat lower than those reported in other regions of the Tibetan Plateau, but the VWM methyl-Hg concentration and deposition flux were among the highest globally reported values. The VWM HgT concentration was higher in non-monsoon season than in monsoon season, and wet HgT deposition was dominated by the precipitation amount rather than the scavenging of atmospheric Hg by precipitation. The dominant Hg species in precipitation was mainly in the form of dissolved Hg, which indicates the pivotal role of reactive gaseous Hg within-cloud scavenging to wet Hg deposition. Moreover, an increasing trend in precipitation Hg concentrations was synchronous with the recent economic development in South Asia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical Bath Deposition and Characterization of CdS layer for CZTS Thin Film Solar Cell

OpenAIRE

Kamal, Tasnim; Parvez, Sheikh; Matin, Rummana; Bashar, Mohammad Shahriar; Hossain, Tasnia; Sarwar, Hasan; Rashid, Mohammad Junaebur

2016-01-01

CZTS is a new type of an absorber and abundant materials for thin film solar cells (TFSC). Cadmium sulfide (CdS) is the n-type buffer layer of it with band gap of 2.42 eV. Cadmium sulfide (CdS) buffer layer of CZTS solar cell was deposited on soda-lime glass substrates by the Chemical Bath Deposition(CBD) method, using anhydrous Cadmium chloride(CdCl_2) and Thiourea (CS(NH_2)_2). Deposition of CdS using CBD is based on the slow release of Cd^ ions and S^ ions in an alkaline bath which is achi...

ELLIPSOMETRIC STUDY OF SEMITRANSPARENT SILVER LAYERS DEPOSITED ON GLASS

Directory of Open Access Journals (Sweden)

Víctor Toranzos

2014-12-01

Full Text Available Using ellipsometry, the film structure is characterized by optical indices n, k (visible region, 450 nm <  < 580 nm and the thickness (15 < d < 35 nm. The optical indices change with the quantity of silver deposited, obtaining effective indices of 1.0 < n < 1.8 and 1.6 < k < 2.6 to the smaller deposits that belong to a volumetric fraction between 0.35 and 0.5 of silver in the air. An effective optical thickness film decrease is observed when the silver volumetric fraction increases, and a thickness increase with close indices to solid silver when the deposited silver increases. Optical and effective medium theory indices are compared.

Characterization of pyroclastic deposits and pre-eruptive soils following the 2008 eruption of Kasatochi Island Volcano, Alaska

Science.gov (United States)

Wang, B.; Michaelson, G.; Ping, C.-L.; Plumlee, G.; Hageman, P.

2010-01-01

The 78 August 2008 eruption of Kasatochi Island volcano blanketed the island in newly generated pyroclastic deposits and deposited ash into the ocean and onto nearby islands. Concentrations of water soluble Fe, Cu, and Zn determined from a 1:20 deionized water leachate of the ash were sufficient to provide short-term fertilization of the surface ocean. The 2008 pyroclastic deposits were thicker in concavities at bases of steeper slopes and thinner on steep slopes and ridge crests. By summer 2009, secondary erosion had exposed the pre-eruption soils along gulley walls and in gully bottoms on the southern and eastern slopes, respectively. Topographic and microtopographic position altered the depositional patterns of the pyroclastic flows and resulted in pre-eruption soils being buried by as little as 1 m of ash. The different erosion patterns gave rise to three surfaces on which future ecosystems will likely develop: largely pre-eruptive soils; fresh pyroclastic deposits influenced by shallowly buried, pre-eruptive soil; and thick (>1 m) pyroclastic deposits. As expected, the chemical composition differed between the pyroclastic deposits and the pre-eruptive soils. Pre-eruptive soils hold stocks of C and N important for establishing biota that are lacking in the fresh pyroclastic deposits. The pyroclastic deposits are a source for P and K but have negligible nutrient holding capacity, making these elements vulnerable to leaching loss. Consequently, the pre-eruption soils may also represent an important long-term P and K source. ?? 2010 Regents of the University of Colorado.

Accurate characterization and understanding of interface trap density trends between atomic layer deposited dielectrics and AlGaN/GaN with bonding constraint theory

Energy Technology Data Exchange (ETDEWEB)

Ramanan, Narayanan; Lee, Bongmook; Misra, Veena, E-mail: vmisra@ncsu.edu [Department of Electrical and Computer Engineering, North Carolina State University, 2410 Campus Shore Drive, Raleigh, North Carolina 27695 (United States)

2015-06-15

Many dielectrics have been proposed for the gate stack or passivation of AlGaN/GaN based metal oxide semiconductor heterojunction field effect transistors, to reduce gate leakage and current collapse, both for power and RF applications. Atomic Layer Deposition (ALD) is preferred for dielectric deposition as it provides uniform, conformal, and high quality films with precise monolayer control of film thickness. Identification of the optimum ALD dielectric for the gate stack or passivation requires a critical investigation of traps created at the dielectric/AlGaN interface. In this work, a pulsed-IV traps characterization method has been used for accurate characterization of interface traps with a variety of ALD dielectrics. High-k dielectrics (HfO{sub 2}, HfAlO, and Al{sub 2}O{sub 3}) are found to host a high density of interface traps with AlGaN. In contrast, ALD SiO{sub 2} shows the lowest interface trap density (<2 × 10{sup 12 }cm{sup −2}) after annealing above 600 °C in N{sub 2} for 60 s. The trend in observed trap densities is subsequently explained with bonding constraint theory, which predicts a high density of interface traps due to a higher coordination state and bond strain in high-k dielectrics.

Growth of different phases and morphological features of MnS thin films by chemical bath deposition: Effect of deposition parameters and annealing

Energy Technology Data Exchange (ETDEWEB)

Hannachi, Amira, E-mail: amira.hannachi88@gmail.com; Maghraoui-Meherzi, Hager

2017-03-15

Manganese sulfide thin films have been deposited on glass slides by chemical bath deposition (CBD) method. The effects of preparative parameters such as deposition time, bath temperature, concentration of precursors, multi-layer deposition, different source of manganese, different complexing agent and thermal annealing on structural and morphological film properties have been investigated. The prepared thin films have been characterized using the X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). It exhibit the metastable forms of MnS, the hexagonal γ-MnS wurtzite phase with preferential orientation in the (002) plane or the cubic β-MnS zinc blende with preferential orientation in the (200) plane. Microstructural studies revealed the formation of MnS crystals with different morphologies, such as hexagons, spheres, cubes or flowers like. - Graphical Abstract: We report the preparation of different phases of manganese sulfide thin films (γ, β and α-MnS) by chemical bath deposition method. The effects of deposition parameters such as deposition time and temperature, concentrations of precursors and multi-layer deposition on MnS thin films structure and morphology were investigated. The influence of thermal annealing under nitrogen atmosphere at different temperature on MnS properties was also studied. Different manganese precursors as well as different complexing agent were also used. - Highlights: • γ and β-MnS films were deposited on substrate using the chemical bath deposition. • The effect of deposition parameters on MnS film properties has been investigated. • Multi-layer deposition was also studied to increase film thickness. • The effect of annealing under N{sub 2} at different temperature was investigated.

Molybdenum Tube Characterization report

Energy Technology Data Exchange (ETDEWEB)

Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-07

Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

In situ deposition of hydroxyapatite on graphene nanosheets

International Nuclear Information System (INIS)

Neelgund, Gururaj M.; Oki, Aderemi; Luo, Zhiping

2013-01-01

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH 4 etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

In situ deposition of hydroxyapatite on graphene nanosheets

Energy Technology Data Exchange (ETDEWEB)

Neelgund, Gururaj M. [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Oki, Aderemi, E-mail: aroki@pvamu.edu [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Luo, Zhiping [Microscopy and Imaging Center and Materials Science and Engineering Program, Texas A and M University, College Station, TX 77843 (United States)

2013-02-15

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH{sub 4} etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

Genetic analysis of intracapillary glomerular lipoprotein deposits in aging mice.

Directory of Open Access Journals (Sweden)

Gerda A Noordmans

Full Text Available Renal aging is characterized by functional and structural changes like decreased glomerular filtration rate, and glomerular, tubular and interstitial damage. To gain insight in pathways involved in renal aging, we studied aged mouse strains and used genetic analysis to identify genes associated with aging phenotypes.Upon morphological screening in kidneys from 20-month-old mice from 26 inbred strains we noted intracapillary PAS-positive deposits. The severity of these deposits was quantified by scoring of a total of 50 glomeruli per section (grade 0-4. Electron microscopy and immunohistochemical staining for apoE, apoB, apoA-IV and perilipin-2 was performed to further characterize the lesions. To identify loci associated with these PAS-positive intracapillary glomerular deposits, we performed haplotype association mapping.Six out of 26 mouse strains showed glomerular PAS-positive deposits. The severity of these deposits varied: NOD(0.97, NZW(0.41, NON(0.30, B10(0.21, C3 H(0.9 and C57BR(0.7. The intracapillary deposits were strongly positive for apoE and weakly positive for apoB and apoA-IV. Haplotype association mapping showed a strong association with a 30-Kb haplotype block on Chr 1 within the Esrrg gene. We investigated 1 Mb on each site of this region, which includes the genes Spata17, Gpatch2, Esrrg, Ush2a and Kctd3.By analyzing 26 aged mouse strains we found that some strains developed an intracapillary PAS and apoE-positive lesion and identified a small haplotype block on Chr 1 within the Esrrg gene to be associated with these lipoprotein deposits. The region spanning this haplotype block contains the genes Spata17, Gpatch2, Esrrg, Ush2a and Kctd3, which are all highly expressed in the kidney. Esrrg might be involved in the evolvement of these glomerular deposits by influencing lipid metabolism and possibly immune reponses.

Deposition and analytical characterization of fluoropolymer thin films modified by palladium nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Cioffi, Nicola; Torsi, Luisa; Farella, Isabella; Altamura, Davide; Valentini, Antonio; Ditaranto, Nicoletta; Sabbatini, Luigia; Zambonin, Pier Giorgio; Bleve-Zacheo, Teresa

2004-02-02

Palladium-fluoropolymer nanostructured composites (Pd-CF{sub x}) are deposited by a separate and simultaneous sputtering of bulk Teflon and palladium targets in a vacuum chamber. Such nano-material can find application as active layer in sensing devices, as it swells when exposed to the vapors of organic solvents such as acetone, chloroform, 2-propanol. Ellipsometry shows that the swelling extent linearly depends on the solvent partial pressure in the measuring chamber. Moreover, Pd-CF{sub x} sensitivity and selectivity features are different to those of a parent gold-fluoropolymer (Au-CF{sub x}) nanocomposite, investigated in previous studies. In particular, Pd-CF{sub x} layers are generally more sensitive than Au-CF{sub x} ones, particularly in the case of chlorinated solvents, which are scarcely detectable by Au-CF{sub x} nanocomposites. The material morphological and chemical structure has been investigated by means of atomic force and transmission electron microscopies along with X-ray photoelectron (XPS) and Fourier transform infra-red spectroscopies. The analytical characterization demonstrates that morphological similarities exist between Pd-CF{sub x} films and Au-CF{sub x} ones having the same metal volume fraction {phi}. XPS also reveals an almost identical surface structure for the dispersing polymer matrix of homologous Pd-CF{sub x} and Au-CF{sub x} films. Metal fluorides and oxides are identified as well and differences in the materials sensing performances are then ascribed to the presence of different amounts of these species that also have a different chemical reactivity and selectivity.

Dosimetric characterization of chemical-vapor-deposited diamond film irradiated with UV and beta radiation

Science.gov (United States)

Meléndrez, R.; Chernov, V.; Pedroza-Montero, M.; Barboza-Flores, M.

2003-03-01

Diamond is an excellent prospect for clinical radiation dosimetry due to its tissue-equivalence properties and being chemically inert. The use of diamond in radiation dosimetry has been halted by the high market price; although recently the capability of growing high quality polycrystalline has renewed the interest in using diamond films as detectors and dosimeters. In the present work we have characterized the dosimetric properties of diamond films synthesized by using chemical vapor deposition. The thermoluminescence (TL) of UV and beta exposed samples shows a glow curve composed of at least four peaks; one located around 587 K presents excellent TL properties suitable for dosimetric applications with ionizing and non ionizing radiation. The TL excitation spectrum exhibits maximum TL efficiency at 220 nm. The samples show regions of linear as well as supralinear behavior as a function or irradiation dose. The linear dose dependence was found for up to sixteen minutes of UV irradiation and 300 Gy for beta irradiated samples. The activation energy and the frequency factor were determined and found in the range of 0.32 - 0.89 eV and 1.1x10^2 - 2x10^8s_-1, respectively. The observed TL performance is reasonable appropriate to justify further investigation of diamond films as radiation dosimeters.

Aerosol Deposition and Solar Panel Performance

Science.gov (United States)

Arnott, W. P.; Rollings, A.; Taylor, S. J.; Parks, J.; Barnard, J.; Holmes, H.

2015-12-01