Implementation of Design Changes Towards a More Reliable, Hands-off Magnetron Ion Source

Energy Technology Data Exchange (ETDEWEB)

Sosa, A. [Fermilab; Bollinger, D. S. [Fermilab; Karns, P. R. [Fermilab; Tan, C. Y. [Fermilab

2017-12-07

As the main H- ion source for the accelerator complex, magnetron ion sources have been used at Fermilab since the 1970’s. At the offline test stand, new R&D is carried out to develop and upgrade the present magnetron-type sources of H- ions of up to 80 mA and 35 keV beam energy in the context of the Proton Improvement Plan. The aim of this plan is to provide high-power proton beams for the experiments at FNAL. In order to reduce the amount of tuning and monitoring of these ion sources, a new electronic system consisting of a current-regulated arc discharge modulator allow the ion source to run at a constant arc current for improved beam output and operation. A solenoid-type gas valve feeds H2 gas into the source precisely and independently of ambient temperature. This summary will cover several studies and design changes that have been tested and will eventually be implemented on the operational magnetron sources at Fermilab. Innovative results for this type of ion source include cathode geometries, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction, with the aim to improve source lifetime, stability, and reducing the amount of tuning needed. In this summary, I will highlight the advances made in ion sources at Fermilab and will outline the directions of the continuing R&D effort.

Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

Czech Academy of Sciences Publication Activity Database

Martines, E.; Zuin, M.; Cavazzana, R.; Adámek, Jiří; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N.

2014-01-01

Roč. 21, č. 10 (2014), s. 102309-102309 ISSN 1070-664X Institutional support: RVO:61389021 Keywords : Drift waves * Magnetron sputtering plasma * Spatiotemporal synchronization Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.142, year: 2014 http://dx.doi.org/10.1063/1.4898693

Study of static properties of magnetron-type space charges; Etude des proprietes statiques des charges d'espace du type magnetron

Energy Technology Data Exchange (ETDEWEB)

Delcroix, Jean-Loup

1953-05-30

This research thesis reports an in-depth analysis of physical properties of static regimes to address the issue of space charges. This theoretical study of the Hull magnetron is followed by the description of experiments on the Hull magnetron which highlight transitions between the different regimes. Then, another theoretical approach aims at generalising the magnetron theory, based on other types of magnetron theory (general equations of magnetron-type space charges, inverted Hull magnetron theory, circular field magnetron theory)

Transparent conducting Al-doped ZnO thin films prepared by magnetron sputtering with dc and rf powers applied in combination

International Nuclear Information System (INIS)

Minami, Tadatsugu; Ohtani, Yuusuke; Miyata, Toshihiro; Kuboi, Takeshi

2007-01-01

A newly developed Al-doped ZnO (AZO) thin-film magnetron-sputtering deposition technique that decreases resistivity, improves resistivity distribution, and produces high-rate depositions has been demonstrated by dc magnetron-sputtering depositions that incorporate rf power (dc+rf-MS), either with or without the introduction of H 2 gas into the deposition chamber. The dc+rf-MS preparations were carried out in a pure Ar or an Ar+H 2 (0%-2%) gas atmosphere at a pressure of 0.4 Pa by adding a rf component (13.56 MHz) to a constant dc power of 80 W. The deposition rate in a dc+rf-MS deposition incorporating a rf power of 150 W was approximately 62 nm/min, an increase from the approximately 35 nm/min observed in dc magnetron sputtering with a dc power of 80 W. A resistivity as low as 3x10 -4 Ω cm and an improved resistivity distribution could be obtained in AZO thin films deposited on substrates at a low temperature of 150 deg. C by dc+rf-MS with the introduction of hydrogen gas with a content of 1.5%. This article describes the effects of adding a rf power component (i.e., dc+rf-MS deposition) as well as introducing H 2 gas into dc magnetron-sputtering preparations of transparent conducting AZO thin films

Inverse magnetostrictive characteristics of Fe-Co composite materials using gas-nitriding process

Science.gov (United States)

Nakajima, Kenya; Yang, Zhenjun; Narita, Fumio

2018-03-01

The inverse magnetostrictive response, known as the Villari effect, of magnetostrictive materials is a change in magnetization due to an applied stress. It is commonly used for sensor applications. This work deals with the inverse magnetostrictive characteristics of Fe-Co bimetal plates that were subjected gas-nitriding process. Gas-nitriding was performed on bimetal plates for 30 min at 853 K as a surface heat treatment process. The specimens were cooled to room temperature after completing the nitriding treatment. Three-point bending tests were performed on the plates under a magnetic field. The changes on the magnetic induction of the plates due to the applied load are discussed. The effect of the nitriding treatment on the inverse magnetostrictive characteristics, magnetostrictive susceptibility, and magnetic hysteresis loop was examined. Our work represents an important step forward in the development of magnetostrictive sensor materials.

Geometric considerations in magnetron sputtering

International Nuclear Information System (INIS)

Thornton, J.A.

1982-01-01

The recent development of high performance magnetron type discharge sources has greatly enhaced the range of coating applications where sputtering is a viable deposition process. Magnetron sources can provide high current densities and sputtering rates, even at low pressures. They have much reduced substrate heating rates and can be scaled to large sizes. Magnetron sputter coating apparatuses can have a variety of geometric and plasma configurations. The target geometry affects the emission directions of both the sputtered atoms and the energetic ions which are neutralized and reflected at the cathode. This fact, coupled with the long mean free particle paths which are prevalent at low pressures, can make the coating properties very dependent on the apparatus geometry. This paper reviews the physics of magnetron operation and discusses the influences of apparatus geometry on the use of magnetrons for rf sputtering and reactive sputtering, as well as on the microstructure and internal stresses in sputtered metallic coatings. (author) [pt

Effects of oxygen addition in reactive cluster beam deposition of tungsten by magnetron sputtering with gas aggregation

Energy Technology Data Exchange (ETDEWEB)

Polášek, J., E-mail: xpolasekj@seznam.cz [Department of Surface and Plasma Science, Faculty of Mathematics and Physic, Charles University, V Holešovičkách 2, Prague 8, CZ-18000 (Czech Republic); Mašek, K. [Department of Surface and Plasma Science, Faculty of Mathematics and Physic, Charles University, V Holešovičkách 2, Prague 8, CZ-18000 (Czech Republic); Marek, A.; Vyskočil, J. [HVM Plasma Ltd., Na Hutmance 2, Prague 5, CZ-158 00 (Czech Republic)

2015-09-30

In this work, we investigated the possibilities of tungsten and tungsten oxide nanoclusters generation by means of non-reactive and reactive magnetron sputtering with gas aggregation. It was found that in pure argon atmosphere, cluster aggregation proceeded in two regimes depending on argon pressure in the aggregation chamber. At the lower pressure, cluster generation was dominated by two-body collisions yielding larger clusters (about 5.5 nm in diameter) at lower rate. At higher pressures, cluster generation was dominated by three-body collisions yielding smaller clusters (3–4 nm in diameter) at higher rate. The small amount of oxygen admixture in the aggregation chamber had considerable influence on cluster aggregation process. At certain critical pressure, the presence of oxygen led to the raise of deposition rate and cluster size. Resulting clusters were composed mostly of tungsten trioxide. The oxygen pressure higher than critical led to the target poisoning and the decrease in the sputtering rate. Critical oxygen pressure decreased with increasing argon pressure, suggesting that cluster aggregation process was influenced by atomic oxygen species (namely, O{sup −} ion) generated by oxygen–argon collisions in the magnetron plasma. - Highlights: • Formation of tungsten and tungsten oxide clusters was observed. • Two modes of cluster aggregation in pure argon atmosphere were found. • Dependence of cluster deposition speed and size on oxygen admixture was observed. • Changes of dependence on oxygen with changing argon pressure were described.

Effects of oxygen addition in reactive cluster beam deposition of tungsten by magnetron sputtering with gas aggregation

International Nuclear Information System (INIS)

Polášek, J.; Mašek, K.; Marek, A.; Vyskočil, J.

2015-01-01

In this work, we investigated the possibilities of tungsten and tungsten oxide nanoclusters generation by means of non-reactive and reactive magnetron sputtering with gas aggregation. It was found that in pure argon atmosphere, cluster aggregation proceeded in two regimes depending on argon pressure in the aggregation chamber. At the lower pressure, cluster generation was dominated by two-body collisions yielding larger clusters (about 5.5 nm in diameter) at lower rate. At higher pressures, cluster generation was dominated by three-body collisions yielding smaller clusters (3–4 nm in diameter) at higher rate. The small amount of oxygen admixture in the aggregation chamber had considerable influence on cluster aggregation process. At certain critical pressure, the presence of oxygen led to the raise of deposition rate and cluster size. Resulting clusters were composed mostly of tungsten trioxide. The oxygen pressure higher than critical led to the target poisoning and the decrease in the sputtering rate. Critical oxygen pressure decreased with increasing argon pressure, suggesting that cluster aggregation process was influenced by atomic oxygen species (namely, O"− ion) generated by oxygen–argon collisions in the magnetron plasma. - Highlights: • Formation of tungsten and tungsten oxide clusters was observed. • Two modes of cluster aggregation in pure argon atmosphere were found. • Dependence of cluster deposition speed and size on oxygen admixture was observed. • Changes of dependence on oxygen with changing argon pressure were described.

Composite Ag/C:H:N films prepared by planar magnetron deposition

Energy Technology Data Exchange (ETDEWEB)

Hlidek, P. [Charles University, Faculty of Mathematics and Physics, Praha (Czech Republic)], E-mail: hlidek@karlov.mff.cuni.cz; Hanus, J.; Biederman, H.; Slavinska, D.; Pesicka, J. [Charles University, Faculty of Mathematics and Physics, Praha (Czech Republic)

2008-05-30

Composite Ag/C:H:N films were deposited by means of an unbalanced magnetron operated in a gas mixture of nitrogen and n-hexane. Composition of the films was controlled by electric power delivered to the magnetron and by ratio of nitrogen and n-hexane in the working gas mixture. The films were characterized using transmission electron microscopy, by the absorption spectra in visible and near infrared regions and by Fourier transform infrared spectroscopy. Immediately after film deposition and without breaking vacuum (in situ) corresponding vibration infrared spectra were scanned and their evolution during ageing of the films was monitored. Wettability as determined from water contact angle was improved with raising nitrogen contents, i.e. with increasing the electric power and the ratio of nitrogen/n-hexane in the working gas mixture. The increased wettability is likely caused by presence of NH{sub x} groups in Ag/C:H:N films. The incorporation of nitrogen effectively prevents the formation of carboxylate groups on the silver inclusions surfaces during the aging in the open air. In addition, the oxidation mechanism of the polymer matrix is modified.

Study of static properties of magnetron-type space charges

International Nuclear Information System (INIS)

Delcroix, Jean-Loup

1953-01-01

This research thesis reports an in-depth analysis of physical properties of static regimes to address the issue of space charges. This theoretical study of the Hull magnetron is followed by the description of experiments on the Hull magnetron which highlight transitions between the different regimes. Then, another theoretical approach aims at generalising the magnetron theory, based on other types of magnetron theory (general equations of magnetron-type space charges, inverted Hull magnetron theory, circular field magnetron theory)

Deposition and characterization of zirconium nitride (ZrN) thin films by reactive magnetron sputtering with linear gas ion source and bias voltage

Energy Technology Data Exchange (ETDEWEB)

Kavitha, A.; Kannan, R. [Department of Physics, University College of Engineering, Anna University, Dindugal-624622 (India); Subramanian, N. Sankara [Department of Physics, Thiagarajar College of Engineering, Madurai -625015, Tamilnadu (India); Loganathan, S. [Ion Plating, Titan Industries Ltd., Hosur - 635126, Tamilnadu (India)

2014-04-24

Zirconium nitride thin films have been prepared on stainless steel substrate (304L grade) by reactive cylindrical magnetron sputtering method with Gas Ion Source (GIS) and bias voltage using optimized coating parameters. The structure and surface morphologies of the ZrN films were characterized using X-ray diffraction, atomic microscopy and scanning electron microscopy. The adhesion property of ZrN thin film has been increased due to the GIS. The coating exhibits better adhesion strength up to 10 N whereas the ZrN thin film with bias voltage exhibits adhesion up to 500 mN.

Inversion of double-difference measurements from optical levelling for the Groningen gas field

Directory of Open Access Journals (Sweden)

P. A. Fokker

2015-11-01

Full Text Available Hydrocarbon extraction lead to compaction of the gas reservoir which is visible as subsidence on the surface. Subsidence measurements can therefore be used to better estimate reservoir parameters. Total subsidence is derived from the result of the measurement of height differences between optical benchmarks. The procedure from optical height difference measurements to absolute subsidence is an inversion, and the result is often used as an input for consequent inversions on the reservoir. We have used the difference measurements directly to invert for compaction of the Groningen gas reservoir in the Netherlands. We have used a linear inversion exercise to update an already existing reservoir compaction model of the field. This procedure yielded areas of increased and decreased levels of compaction compared to the existing compaction model in agreement with observed discrepancies in porosity and aquifer activity.

Discharge runaway in high power impulse magnetron sputtering of carbon: the effect of gas pressure, composition and target peak voltage

Science.gov (United States)

Vitelaru, Catalin; Aijaz, Asim; Constantina Parau, Anca; Kiss, Adrian Emil; Sobetkii, Arcadie; Kubart, Tomas

2018-04-01

Pressure and target voltage driven discharge runaway from low to high discharge current density regimes in high power impulse magnetron sputtering of carbon is investigated. The main purpose is to provide a meaningful insight of the discharge dynamics, with the ultimate goal to establish a correlation between discharge properties and process parameters to control the film growth. This is achieved by examining a wide range of pressures (2–20 mTorr) and target voltages (700–850 V) and measuring ion saturation current density at the substrate position. We show that the minimum plasma impedance is an important parameter identifying the discharge transition as well as establishing a stable operating condition. Using the formalism of generalized recycling model, we introduce a new parameter, ‘recycling ratio’, to quantify the process gas recycling for specific process conditions. The model takes into account the ion flux to the target, the amount of gas available, and the amount of gas required for sustaining the discharge. We show that this parameter describes the relation between the gas recycling and the discharge current density. As a test case, we discuss the pressure and voltage driven transitions by changing the gas composition when adding Ne into the discharge. We propose that standard Ar HiPIMS discharges operated with significant gas recycling do not require Ne to increase the carbon ionization.

Prestack inversion based on anisotropic Markov random field-maximum posterior probability inversion and its application to identify shale gas sweet spots

Science.gov (United States)

Wang, Kang-Ning; Sun, Zan-Dong; Dong, Ning

2015-12-01

Economic shale gas production requires hydraulic fracture stimulation to increase the formation permeability. Hydraulic fracturing strongly depends on geomechanical parameters such as Young's modulus and Poisson's ratio. Fracture-prone sweet spots can be predicted by prestack inversion, which is an ill-posed problem; thus, regularization is needed to obtain unique and stable solutions. To characterize gas-bearing shale sedimentary bodies, elastic parameter variations are regarded as an anisotropic Markov random field. Bayesian statistics are adopted for transforming prestack inversion to the maximum posterior probability. Two energy functions for the lateral and vertical directions are used to describe the distribution, and the expectation-maximization algorithm is used to estimate the hyperparameters of the prior probability of elastic parameters. Finally, the inversion yields clear geological boundaries, high vertical resolution, and reasonable lateral continuity using the conjugate gradient method to minimize the objective function. Antinoise and imaging ability of the method were tested using synthetic and real data.

Computer simulation of sputtering of graphite target in magnetron sputtering device with two zones of erosion

Directory of Open Access Journals (Sweden)

Bogdanov R.V.

2015-03-01

Full Text Available A computer simulation program for discharge in a magnetron sputtering device with two erosion zones was developed. Basic laws of the graphite target sputtering process and transport of sputtered material to the substrate were taken into account in the Monte Carlo code. The results of computer simulation for radial distributions of density and energy flux of carbon atoms on the substrate (at different values of discharge current and pressure of the working gas confirmed the possibility of obtaining qualitative homogeneous films using this magnetron sputtering device. Also the discharge modes were determined for this magnetron sputtering device, in which it was possible to obtain such energy and density of carbon atoms fluxes, which were suitable for deposition of carbon films containing carbon nanotubes and other nanoparticles.

Effect of deposition parameters on properties of ITO films prepared by reactive middle frequency pulsed dual magnetron sputtering

International Nuclear Information System (INIS)

Rogozin, A.I.; Vinnichenko, M.V.; Kolitsch, A.; Moeller, W.

2004-01-01

ITO layers with low resistivity and high visible transmittance were produced by means of middle frequency reactive dual magnetron sputtering. The influence of base pressure, Ar/O 2 ratio and magnetron pulse duration on the film composition, structure, electrical, and optical properties has been investigated. The deposition rate is proportional to the magnetron operation power at changing pulse duration and constant Ar and O 2 flows. At enhanced O 2 flows an onset of the magnetron target oxidation is discussed as a reason for the decrease of the deposition rate. The presence of water vapor in the residual gas is determined to be a reason for deterioration of resistivity and optical transmittance observed for ITO films produced at a base pressures higher than 5·10 -4 Pa. It is demonstrated that spectroscopic ellipsometry can be used as a noncontact tool to monitor the resistivity of ITO films

Analysis of peer-to-peer locking of magnetrons

International Nuclear Information System (INIS)

Pengvanich, P.; Lau, Y. Y.; Cruz, E.; Gilgenbach, R. M.; Hoff, B.; Luginsland, J. W.

2008-01-01

The condition for mutual, or peer-to-peer, locking of two magnetrons is derived. This condition reduces to Adler's classical phase-locking condition in the limit where one magnetron becomes the ''master'' and the other becomes the ''slave.'' The formulation is extended to the peer-to-peer locking of N magnetrons, under the assumption that the electromagnetic coupling among the N magnetrons is modeled by an N-port network.

Stability of Brillouin flow in planar, conventional, and inverted magnetrons

International Nuclear Information System (INIS)

Simon, D. H.; Lau, Y. Y.; Greening, G.; Wong, P.; Gilgenbach, R. M.; Hoff, B. W.

2015-01-01

The Brillouin flow is the prevalent flow in crossed-field devices. We systematically study its stability in the conventional, planar, and inverted magnetron geometry. To investigate the intrinsic negative mass effect in Brillouin flow, we consider electrostatic modes in a nonrelativistic, smooth bore magnetron. We found that the Brillouin flow in the inverted magnetron is more unstable than that in a planar magnetron, which in turn is more unstable than that in the conventional magnetron. Thus, oscillations in the inverted magnetron may startup faster than the conventional magnetron. This result is consistent with simulations, and with the negative mass property in the inverted magnetron configuration. Inclusion of relativistic effects and electromagnetic effects does not qualitatively change these conclusions

Overview of recent studies and design changes for the FNAL magnetron ion source

Science.gov (United States)

Bollinger, D. S.; Sosa, A.

2017-08-01

This paper presents several studies and design changes that will eventually be implemented to the Fermi National Accelerator Laboratory (FNAL) magnetron ion source. The topics include tungsten cathode insert, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction. The studies were performed on the FNAL test stand described in [1], with the aim to improve source lifetime, stability, and reducing the amount of tuning needed.

Overview of Recent Studies and Design Changes for the FNAL Magnetron Ion Source

Energy Technology Data Exchange (ETDEWEB)

Bollinger, D. S. [Fermilab; Sosa, A. [Fermilab

2016-09-06

This paper will cover several studies and design changes that will eventually be implemented to the Fermi National Accelerator Laboratory (FNAL) magnetron ion source. The topics include tungsten cathode insert, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction. The studies were performed on the FNAL test stand described in [1], with the aim to improve source lifetime, stability, and reducing the amount of tuning needed.

Negative Ion Sources: Magnetron and Penning

CERN Document Server

Faircloth, D.C.

2013-12-16

The history of the magnetron and Penning electrode geometry is briefly outlined. Plasma generation by electrical discharge-driven electron impact ionization is described and the basic physics of plasma and electrodes relevant to magnetron and Penning discharges are explained. Negative ions and their applications are introduced, along with their production mechanisms. Caesium and surface production of negative ions are detailed. Technical details of how to build magnetron and Penning surface plasma sources are given, along with examples of specific sources from around the world. Failure modes are listed and lifetimes compared.

Negative Ion Sources: Magnetron and Penning

International Nuclear Information System (INIS)

Faircloth, D C

2013-01-01

The history of the magnetron and Penning electrode geometry is briefly outlined. Plasma generation by electrical discharge-driven electron impact ionization is described and the basic physics of plasma and electrodes relevant to magnetron and Penning discharges are explained. Negative ions and their applications are introduced, along with their production mechanisms. Caesium and surface production of negative ions are detailed. Technical details of how to build magnetron and Penning surface plasma sources are given, along with examples of specific sources from around the world. Failure modes are listed and lifetimes compared. (author)

Depth profile analyses of nc-TiC/a-C:H coating prepared by balanced magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Vašina, P.; Souček, P.; Schmidtová, T.; Eliáš, M.; Buršíková, V.; Jílek, M.; Jílek Jr., M.; Schäfer, C.; Buršík, Jiří

2011-01-01

Roč. 205, Suppl. 2 (2011), S53-S56 ISSN 0257-8972 Institutional research plan: CEZ:AV0Z20410507 Keywords : composite * mechanical properties * magnetron Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.867, year: 2011

Influence of reactive gas admixture on transition metal cluster nucleation in a gas aggregation cluster source

Science.gov (United States)

Peter, Tilo; Polonskyi, Oleksandr; Gojdka, Björn; Mohammad Ahadi, Amir; Strunskus, Thomas; Zaporojtchenko, Vladimir; Biederman, Hynek; Faupel, Franz

2012-12-01

We quantitatively assessed the influence of reactive gases on the formation processes of transition metal clusters in a gas aggregation cluster source. A cluster source based on a 2 in. magnetron is used to study the production rate of titanium and cobalt clusters. Argon served as working gas for the DC magnetron discharge, and a small amount of reactive gas (oxygen and nitrogen) is added to promote reactive cluster formation. We found that the cluster production rate depends strongly on the reactive gas concentration for very small amounts of reactive gas (less than 0.1% of total working gas), and no cluster formation takes place in the absence of reactive species. The influence of discharge power, reactive gas concentration, and working gas pressure are investigated using a quartz micro balance in a time resolved manner. The strong influence of reactive gas is explained by a more efficient formation of nucleation seeds for metal-oxide or nitride than for pure metal.

A microcontroller based tuning mechanism for the magnetron

International Nuclear Information System (INIS)

Khan, A.M.; Mahfooz, M.; Hanumaiah, B.; Ganesh; Siddappa, K.

2006-01-01

In this paper we report on a control system developed to tune the magnetron frequency to get the maximum beam pulse in the microtron (electron accelerator facility at Mangalore University). The control system so designed consists of a microcontroller, a phase locked loop (PLL) and a digital to analog converter (DAC) to control the magnetron frequency. The voltage value given by the microcontroller through the DAC decides the reference frequency. The PLL gives the error voltage whenever there is difference between the reference and the magnetron frequencies. The microcontroller unit tracks the error voltage and tunes the magnetron with the help of a tuner mechanism connected through a stepper motor. The microcontroller also monitors the beam current level and accordingly adjusts the reference frequency to successfully tune the magnetron. (author)

Recent operation of the FNAL magnetron H- ion source

Science.gov (United States)

Karns, P. R.; Bollinger, D. S.; Sosa, A.

2017-08-01

This paper will detail changes in the operational paradigm of the Fermi National Accelerator Laboratory (FNAL) magnetron H- ion source due to upgrades in the accelerator system. Prior to November of 2012 the H- ions for High Energy Physics (HEP) experiments were extracted at ˜18 keV vertically downward into a 90 degree bending magnet and accelerated through a Cockcroft-Walton accelerating column to 750 keV. Following the upgrade in the fall of 2012 the H- ions are now directly extracted from a magnetron at 35 keV and accelerated to 750 keV by a Radio Frequency Quadrupole (RFQ). This change in extraction energy as well as the orientation of the ion source required not only a redesign of the ion source, but an updated understanding of its operation at these new values. Discussed in detail are the changes to the ion source timing, arc discharge current, hydrogen gas pressure, and cesium delivery system that were needed to maintain consistent operation at >99% uptime for HEP, with an increased ion source lifetime of over 9 months.

CEERI-CAT joint venture for development of accelerator magnetrons

International Nuclear Information System (INIS)

Prasad, Sharda; Kaushik, S.C.; Mahesh Kumar; Chaudhary, P.; Shrivastava, Purushottam; Wanmode, Y.; Hannurkar, P.R.

2003-01-01

LINAC and Microtron systems for electron acceleration up to few tens of MeV, requires pulsed RF sources such as magnetron and klystron in S-Band frequency range with peak power in the range of few MW. The major emphasis under this program was to develop critical technologies involved in the development of 2 MW magnetron. This paper discusses the development of 2 MW magnetron along with critical technologies involved and test facilities developed by CAT for testing of this magnetron

Estimation of Sputtering Damages on a Magnetron H- Ion Source Induced by Cs+ and H+ Ions

CERN Document Server

Pereira, H; Alessi, J; Kalvas, t

2013-01-01

An H− ion source is being developed for CERN’s Linac4 accelerator. A beam current requirement of 80 mA and a reliability above 99% during 1 year with 3 month uninterrupted operation periods are mandatory. To design a low-maintenance long life-time source, it is important to investigate and understand the wear mechanisms. A cesiated plasma discharge ion source, such as the BNL magnetron source, is a good candidate for the Linac4 ion source. However, in the magnetron source operated at BNL, the removal of material from the molybdenum cathode and the stainless steel anode cover plate surfaces is visible after extended operation periods. The observed sputtering traces are shown to result from cesium vapors and hydrogen gas ionized in the extraction region and subsequently accelerated by the extraction field. This paper presents a quantitative estimate of the ionization of cesium and hydrogen by the electron and H− beams in the extraction region of BNL’s magnetron ion source. The respective contributions o...

Deposition of lead-silicate glassy thin coatings by RF magnetron sputtering: Correlation between deposition parameters and electrical and structural properties

International Nuclear Information System (INIS)

Rigato, V.; Maggioni, G.; Boscarino, D.; Della Mea, G.; Univ. di Trento, Mesiano

1996-01-01

Lead-silicate glassy thin films produced by means of Reactive Radio Frequency Magnetron Sputtering have found recent application in the development of MicroStrip Gas Chambers radiation detectors. Here, thin films (100--400 nm) of lead silicate glass have been deposited by RF magnetron sputtering in Ar plasma at different discharge conditions. The interaction of the sputtered species with the gas atoms during the transport process through the discharge region and the kinetics of growth of the films have been investigated as a function of the target composition and of the substrate temperature. This study demonstrates the possibility of controlling the surface electrical resistance of the films in a wide range of values ranging from 10 12 to 10 17 Ω/□ during the film growth

The properties of the wood-polystyrene interphase determined by inverse gas chromatography

Science.gov (United States)

John Simonsen; Zhenqiu Hong; Timothy G. Rials

1997-01-01

The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inoranic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass...

An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments

Science.gov (United States)

Chand, S.; Minshull, T.A.; Priest, J.A.; Best, A.I.; Clayton, C.R.I.; Waite, W.F.

2006-01-01

The presence of gas hydrate in marine sediments alters their physical properties. In some circumstances, gas hydrate may cement sediment grains together and dramatically increase the seismic P- and S-wave velocities of the composite medium. Hydrate may also form a load-bearing structure within the sediment microstructure, but with different seismic wave attenuation characteristics, changing the attenuation behaviour of the composite. Here we introduce an inversion algorithm based on effective medium modelling to infer hydrate saturations from velocity and attenuation measurements on hydrate-bearing sediments. The velocity increase is modelled as extra binding developed by gas hydrate that strengthens the sediment microstructure. The attenuation increase is modelled through a difference in fluid flow properties caused by different permeabilities in the sediment and hydrate microstructures. We relate velocity and attenuation increases in hydrate-bearing sediments to their hydrate content, using an effective medium inversion algorithm based on the self-consistent approximation (SCA), differential effective medium (DEM) theory, and Biot and squirt flow mechanisms of fluid flow. The inversion algorithm is able to convert observations in compressional and shear wave velocities and attenuations to hydrate saturation in the sediment pore space. We applied our algorithm to a data set from the Mallik 2L–38 well, Mackenzie delta, Canada, and to data from laboratory measurements on gas-rich and water-saturated sand samples. Predictions using our algorithm match the borehole data and water-saturated laboratory data if the proportion of hydrate contributing to the load-bearing structure increases with hydrate saturation. The predictions match the gas-rich laboratory data if that proportion decreases with hydrate saturation. We attribute this difference to differences in hydrate formation mechanisms between the two environments.

Investigation of the time evolution of plasma parameters in a pulsed magnetron discharge

Czech Academy of Sciences Publication Activity Database

Straňák, V.; Hubička, Zdeněk; Adámek, P.; Blažek, J.; Tichý, M.; Špatenka, P.; Hippler, R.; Wrehde, S.

2006-01-01

Roč. 56, - (2006), s. 1364-1370 ISSN 0011-4626 R&D Projects: GA ČR GA202/05/2242; GA ČR GA202/06/0776 Grant - others:Deutsche Forschungsgemeinschaft(DE) SFB/TR 24 Institutional research plan: CEZ:AV0Z10100522 Keywords : pulsed magnetron * time resolved measurements * Langmuir probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

Vehicle exhaust gas clearance by low temperature plasma-driven nano-titanium dioxide film prepared by radiofrequency magnetron sputtering.

Directory of Open Access Journals (Sweden)

Shuang Yu

Full Text Available A novel plasma-driven catalysis (PDC reactor with special structure was proposed to remove vehicle exhaust gas. The PDC reactor which consisted of three quartz tubes and two copper electrodes was a coaxial dielectric barrier discharge (DBD reactor. The inner and outer electrodes firmly surrounded the outer surface of the corresponding dielectric barrier layer in a spiral way, respectively. Nano-titanium dioxide (TiO2 film prepared by radiofrequency (RF magnetron sputtering was coated on the outer wall of the middle quartz tube, separating the catalyst from the high voltage electrode. The spiral electrodes were designed to avoid overheating of microdischarges inside the PDC reactor. Continuous operation tests indicated that stable performance without deterioration of catalytic activity could last for more than 25 h. To verify the effectiveness of the PDC reactor, a non-thermal plasma(NTP reactor was employed, which has the same structure as the PDC reactor but without the catalyst. The real vehicle exhaust gas was introduced into the PDC reactor and NTP reactor, respectively. After the treatment, compared with the result from NTP, the concentration of HC in the vehicle exhaust gas treated by PDC reactor reduced far more obviously while that of NO decreased only a little. Moreover, this result was explained through optical emission spectrum. The O emission lines can be observed between 870 nm and 960 nm for wavelength in PDC reactor. Together with previous studies, it could be hypothesized that O derived from catalytically O3 destruction by catalyst might make a significant contribution to the much higher HC removal efficiency by PDC reactor. A series of complex chemical reactions caused by the multi-components mixture in real vehicle exhaust reduced NO removal efficiency. A controllable system with a real-time feedback module for the PDC reactor was proposed to further improve the ability of removing real vehicle exhaust gas.

Photomodulated reflectance study on optical property of InN thin films grown by reactive gas-timing rf magnetron sputtering

International Nuclear Information System (INIS)

Porntheeraphat, S.; Nukeaw, J.

2008-01-01

The photoreflectance (PR) spectroscopy has been applied to investigate the band-gap energy (E g ) of indium nitride (InN) thin films grown by rf magnetron sputtering. A novel reactive gas-timing technique applied for the sputtering process has been successfully employed to grow InN thin films without neither substrate heating nor post annealing. The X-ray diffraction (XRD) patterns exhibit strong peaks in the orientation along (0 0 2) and (1 0 1) planes, corresponding to the polycrystalline hexagonal-InN structure. The band-gap transition energy of InN was determined by fitting the PR spectra to a theoretical line shape. The PR results show the band-gap energy at 1.18 eV for hexagonal-InN thin films deposited at the rf powers of 100 and 200 W. The high rf sputtering powers in combination with the gas-timing technique should lead to a high concentration of highly excited nitrogen ions in the plasma, which enables the formation of InN without substrate heating. Auger electron spectroscopy (AES) measurements further reveal traces of oxygen in these InN films. This should explain the elevated band-gap energy, in reference to the band-gap value of 0.7 eV for pristine InN films

Modeling and experimental studies of a side band power re-injection locked magnetron

Science.gov (United States)

Ye, Wen-Jun; Zhang, Yi; Yuan, Ping; Zhu, Hua-Cheng; Huang, Ka-Ma; Yang, Yang

2016-12-01

A side band power re-injection locked (SBPRIL) magnetron is presented in this paper. A tuning stub is placed between the external injection locked (EIL) magnetron and the circulator. Side band power of the EIL magnetron is reflected back to the magnetron. The reflected side band power is reused and pulled back to the central frequency. A phase-locking model is developed from circuit theory to explain the process of reuse of side band power in SBPRIL magnetron. Theoretical analysis proves that the side band power is pulled back to the central frequency of the SBPRIL magnetron, then the amplitude of the RF voltage increases and the phase noise performance is improved. Particle-in-cell (PIC) simulation of a 10-vane continuous wave (CW) magnetron model is presented. Computer simulation predicts that the frequency spectrum’s peak of the SBPRIL magnetron has an increase of 3.25 dB compared with the free running magnetron. The phase noise performance at the side band offset reduces 12.05 dB for the SBPRIL magnetron. Besides, the SBPRIL magnetron experiment is presented. Experimental results show that the spectrum peak rises by 14.29% for SBPRIL magnetron compared with the free running magnetron. The phase noise reduces more than 25 dB at 45-kHz offset compared with the free running magnetron. Project supported by the National Basic Research Program of China (Grant No. 2013CB328902) and the National Natural Science Foundation of China (Grant No. 61501311).

Investigation of surface properties of physico-chemically modified natural fibres using inverse gas chromatography

CSIR Research Space (South Africa)

Cordeiro, N

2011-01-01

Full Text Available Inverse gas chromatography (IGC) is a suitable method to determine surface energy of natural fibres when compared to wetting techniques. In the present study, the surface properties of raw and modified lignocellulosic fibres have been investigated...

Pulsed Power Generators For Two-section Lia Relativistic Magnetron Driver

CERN Document Server

Agafonov, A V; Pevchev, V P

2004-01-01

Two prototypes of pulsed power generators for a two-sectional LIA - specialized driver of a relativistic magnetron were constructed and tested. The driver for the double-sided powering of a relativistic magnetron consists of two identical sets of induction modules (two sections of LIA) with inner electrodes - vacuum adders connected to both sides of a coaxial magnetron. It provides the symmetric power flowing in a magnetron and a possibility of localising of the electron flow in magnetron interaction region. The first generator designed for a small-scale laboratory installation provides the output pulses of 100 ns in duration with voltage amplitude of 50 kV at repetition rate of 1 pps. The construction of the generator is based on the application of experimental capacitor banks designed as a pulse forming line with the next parameters: charging voltage - 80 kV, impedance - 1,7 Ohm, pulse duration - 80 ns at a matched load. The second generator was designed for 1 MV integrated LIA - magnetron system. It cons...

Composite SiOx/hydrocarbon plasma polymer films prepared by RF magnetron sputtering of SiO2 and polyimide

Czech Academy of Sciences Publication Activity Database

Drabik, M.; Kousal, J.; Pinosh, Y.; Choukourov, A.; Biederman, H.; Slavínská, D.; Macková, Anna; Boldyryeva, Hanna; Pešička, J.

2007-01-01

Roč. 81, č. 7 (2007), s. 920-927 ISSN 0042-207X Institutional research plan: CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering * polyimide * SiO2 Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.881, year: 2007

Inverted relativistic magnetron with a single axial output

International Nuclear Information System (INIS)

Ballard, W.P.; Earley, L.M.; Wharton, C.B.

1986-01-01

A twelve vane, 1 MV, S-band magnetron has been designed and tested. An inverted design was selected to minimize the parasitic axial electron losses. The stainless steel anode is approximately one wavelength long. One end is partially short-circuited to rf, while the other end has a mode transformer to couple the 3.16 GHz π-mode out into a TM 01 circular waveguide. The magnetron has a loaded output Q of about 100. Operation at 1 MV, 0.31 T, 5 kA routinely produces approx.150 MW peak rms and 100 MW average rms with pulse lengths adjustable from 5 to 70 ns. The microwave power pulse has a rise time of approx.2 ns. The output power is diagnosed using four methods: calorimetry, two circular-waveguide directional couplers installed on the magnetron, two transmitting-receiving systems, and gaseous breakdown. Operation at other voltages and magnetic fields shows that the oscillation frequency is somewhat dependent on the magnetron current. Frequency changes of approx.20 MHz/kA occur as the operating conditions are varied. A series of experiments varying the anode conductivity, the electron emission profile, and the output coupling transformer design showed that none of these significantly increased the output power. Therefore, we have concluded that this magnetron operates in saturation. Because of the anode lifetime and repeatability, this magnetron has the potential to be repetitively pulsed. 36 refs., 16 figs

Bonding structure and morphology of chromium oxide films grown by pulsed-DC reactive magnetron sputter deposition

Energy Technology Data Exchange (ETDEWEB)

Gago, R., E-mail: rgago@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, E-28049 Madrid (Spain); Vinnichenko, M. [Fraunhofer-Institut für Keramische Technologien und Systeme IKTS, D-01277 Dresden (Germany); Hübner, R. [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, 01328 Dresden (Germany); Redondo-Cubero, A. [Departamento de Física Aplicada and Centro de Microanálisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain)

2016-07-05

Chromium oxide (CrO{sub x}) thin films were grown by pulsed-DC reactive magnetron sputter deposition in an Ar/O{sub 2} discharge as a function of the O{sub 2} fraction in the gas mixture (ƒ) and for substrate temperatures, T{sub s}, up to 450 °C. The samples were analysed by Rutherford backscattering spectrometry (RBS), spectroscopic ellipsometry (SE), atomic force microscopy (AFM), scanning (SEM) and transmission (TEM) electron microscopy, X-ray diffraction (XRD), and X-ray absorption near-edge structure (XANES). On unheated substrates, by increasing ƒ the growth rate is higher and the O/Cr ratio (x) rises from ∼2 up to ∼2.5. Inversely, by increasing T{sub s} the atomic incorporation rate drops and x falls to ∼1.8. XRD shows that samples grown on unheated substrates are amorphous and that nanocrystalline Cr{sub 2}O{sub 3} (x = 1.5) is formed by increasing T{sub s}. In amorphous CrO{sub x}, XANES reveals the presence of multiple Cr environments that indicate the growth of mixed-valence oxides, with progressive promotion of hexavalent states with ƒ. XANES data also confirms the formation of single-phase nanocrystalline Cr{sub 2}O{sub 3} at elevated T{sub s}. These structural changes also reflect on the optical and morphological properties of the films. - Highlights: • XANES of CrO{sub x} thin films grown by pulsed-DC reactive magnetron sputtering. • Identification of mixed-valence amorphous CrO{sub x} oxides on unheated substrates. • Promotion of amorphous chromic acid (Cr{sup VI}) by increasing O{sub 2} partial pressure. • Production of single-phase Cr{sub 2}O{sub 3} films by increasing substrate temperature. • Correlation of bonding structure with morphological and optical properties.

Determination of adsorption isotherms of chlorinated hydrocarbons on halloysite adsorbent by inverse gas chromatography.

Science.gov (United States)

Czech, K; Słomkiewicz, P M

2013-05-03

Inverse gas chromatographic methods of isotherm determination peak maximum (PM) and peak division (PD) were compared. These methods were applied to determine adsorption isotherms of dichloroethylene, trichloroethylene and tetrachloroethylene on acid-activated halloysite and adsorption enthalpy. Copyright © 2013 Elsevier B.V. All rights reserved.

Structural and electrical properties of sputtering power and gas pressure on Ti-dope In2O3 transparent conductive films by RF magnetron sputtering

Science.gov (United States)

Chaoumead, Accarat; Joo, Bong-Hyun; Kwak, Dong-Joo; Sung, Youl-Moon

2013-06-01

Transparent conductive titanium-doped indium oxide (ITiO) films were deposited on Corning glass substrates by RF magnetron sputtering method. The effects of RF sputtering power and Ar gas pressure on the structural and electrical properties of the films were investigated experimentally, using a 2.5 wt% TiO2-doped In2O3 target. The deposition rate was in the range of around 20-60 nm/min under the experimental conditions of 5-20 mTorr of gas pressure and 220-350 W of RF power. The lowest resistivity of 1.2 × 10-4 Ω cm, the average optical transmittance of 75%, the high hall mobility of 47.03 cm2/V s and the relatively low carrier concentration of 1.15E+21 cm-3 were obtained for the ITiO film, prepared at RF power of 300 W and Ar gas pressure of 15 mTorr. This resistivity of 1.2 × 10-4 Ω cm is low enough as a transparent conducting layer in various electro-optical devices and it is comparable with that of ITO or ZnO:Al conducting layer.

A PLL based automated magnetron tuning mechanism for electron accelerators

International Nuclear Information System (INIS)

Khan, A M; Mahfooz, Mohammed; Sanjeev, Ganesh

2008-01-01

In this paper we report on a control system developed to tune the magnetron frequency to get the maximum beam pulse in a Microtron (an electron accelerator facility at Mangalore University). The control system so designed consists of a Microcontroller Unit (MCU), a Phase Locked Loop (PLL) and a Digital to Analog Converter (DAC) to track and tune the magnetron frequency. A PLL is used to track the deviation of the magnetron output frequency, and by monitoring the reflected wave voltage level, the microcontroller unit tunes the magnetron with the help of a tuner mechanism connected through a stepper motor.

A PLL based automated magnetron tuning mechanism for electron accelerators

Energy Technology Data Exchange (ETDEWEB)

Khan, A M; Mahfooz, Mohammed [Dept. of Electronics, Mangalore University, Mangalagangotri, Karnataka State, India - 574 199 (India); Sanjeev, Ganesh [Microtron Centre, Mangalore University, Mangalagangotri, Karnataka State, India - 574 199 (India)], E-mail: mahfooz_81@yahoo.com

2008-09-15

In this paper we report on a control system developed to tune the magnetron frequency to get the maximum beam pulse in a Microtron (an electron accelerator facility at Mangalore University). The control system so designed consists of a Microcontroller Unit (MCU), a Phase Locked Loop (PLL) and a Digital to Analog Converter (DAC) to track and tune the magnetron frequency. A PLL is used to track the deviation of the magnetron output frequency, and by monitoring the reflected wave voltage level, the microcontroller unit tunes the magnetron with the help of a tuner mechanism connected through a stepper motor.

Highly stable hydrogenated gallium-doped zinc oxide thin films grown by DC magnetron sputtering using H2/Ar gas

International Nuclear Information System (INIS)

Takeda, Satoshi; Fukawa, Makoto

2004-01-01

The effects of water partial pressure (P H 2 O ) on electrical and optical properties of Ga-doped ZnO films grown by DC magnetron sputtering were investigated. With increasing P H 2 O , the resistivity (ρ) of the films grown in pure Ar gas (Ar-films) significantly increased due to the decrease in both free carrier density and Hall mobility. The transmittance in the wavelength region of 300-400 nm for the films also increased with increasing P H 2 O . However, no significant P H 2 O dependence of the electrical and optical properties was observed for the films grown in H 2 /Ar gas mixture (H 2 /Ar-films). Secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD) analysis revealed that hydrogen concentration in the Ar-films increased with increasing P H 2 O and grain size of the films decreases with increasing the hydrogen concentration. These results indicate that the origin of the incorporated hydrogen is attributed to the residual water vapor in the coating chamber, and that the variation of ρ and transmittance along with P H 2 O of the films resulted from the change in the grain size. On the contrary, the hydrogen concentration in H 2 /Ar-films was almost constant irrespective of P H 2 O and the degree of change in the grain size of the films versus P H 2 O was much smaller than that of Ar-films. These facts indicate that the hydrogen primarily comes from H 2 gas and the adsorption species due to H 2 gas preferentially adsorb to the growing film surface over residual water vapor. Consequently, the effects of P H 2 O on the crystal growth are reduced

Phase and Frequency Locked Magnetrons for SRF Sources

International Nuclear Information System (INIS)

Neubauer, M.; Johnson, R.P.; Popovic, M.; Moretti, A.

2009-01-01

Magnetrons are low-cost highly-efficient microwave sources, but they have several limitations, primarily centered about the phase and frequency stability of their output. When the stability requirements are low, such as for medical accelerators or kitchen ovens, magnetrons are the very efficient power source of choice. But for high energy accelerators, because of the need for frequency and phase stability - proton accelerators need 1-2 degrees source phase stability, and electron accelerators need .1-.2 degrees of phase stability - they have rarely been used. We describe a novel variable frequency cavity technique which will be utilized to phase and frequency lock magnetrons.

Deposition of amino-rich thin films by RF magnetron sputtering of nylon

Energy Technology Data Exchange (ETDEWEB)

Kylian, O; Hanus, J; Choukourov, A; Kousal, J; SlavInska, D; Biederman, H, E-mail: ondrej.kylian@gmail.co [Charles University, Faculty of Mathematics and Physics, V Holesovickach 2, Prague 8, 180 00 (Czech Republic)

2009-07-21

RF magnetron sputtering of a nylon target in different gas mixtures was studied in order to evaluate the capability of this process to deposit amino-rich coatings needed in a wide range of biomedical applications. It has been demonstrated that both the deposition rate of the coatings and the surface density of primary amino groups are strongly linked with working gas mixture composition. From this point of view, a sufficiently high deposition rate as well as the highest amine efficiency reaching a NH{sub 2}/C value of 18% was observed in the N{sub 2}/H{sub 2} discharge, which leads to the surface exhibiting a high rate of protein adsorption. (fast track communication)

Evaluation of composition, mechanical properties and structure of nc-TiC/a-C:H coatings prepared by balanced magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Souček, P.; Schmidtová, T.; Zábranský, L.; Buršíková, V.; Vašina, P.; Caha, O.; Jílek, M.; Abdelazziz, El Mel.; Tessier, P.Y.; Schäfer, J.; Buršík, Jiří; Peřina, Vratislav; Mikšová, Romana

2012-01-01

Roč. 211, OCT 25 (2012), s. 111-116 ISSN 0257-8972 Institutional support: RVO:68081723 ; RVO:61389005 Keywords : nanocomposite * magnetron sputtering * titanium Subject RIV: JI - Composite Materials; BL - Plasma and Gas Discharge Physics (UJF-V) Impact factor: 1.941, year: 2012

Comparative study of niobium nitride coatings deposited by unbalanced and balanced magnetron sputtering

International Nuclear Information System (INIS)

Olaya, J.J.; Rodil, S.E.; Muhl, S.

2008-01-01

Niobium nitride (NbN) coatings have many interesting properties such as chemical inertness, excellent mechanical properties, high electrical conductivity, high melting point, and a superconducting transition temperature between 16 and 17 K. For this reason, these compounds have many potential thin film applications. In this work we compare the properties of NbN x films deposited using well-characterized balanced and unbalanced magnetron sputtering systems. Samples of NbN were deposited in the two systems under almost identical deposition conditions, that is, the same substrate temperature, plasma power, gas pressure, substrate to target distance and Ar/N 2 ratio. Prior to the film preparation both the magnetic field geometry and the characteristics of the plasma were determined. The microstructure and composition of the deposits were analyzed by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The corrosion resistance and the micro-abrasion wear resistance were measured by anodic polarization potentiodynamic studies and by ball cratering, respectively. The NbN films grown using the highly unbalanced magnetron configuration had a preferential (111) crystal orientation and a composite hardness of up to 2400 HV 0.025 . While the films deposited using the balanced magnetron had a mixed crystalline orientation and a hardness of 2000 HV 0.025 . The results demonstrate the strong effect of magnetic field configuration on the ion bombardment, and the resultant coating characteristics

Comparative study of niobium nitride coatings deposited by unbalanced and balanced magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Olaya, J.J. [Departamento de Ingenieria Mecanica y Mecatronica, Universidad Nacional de Colombia, Bogota Colombia (Colombia); Rodil, S.E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Mexico D. F. 04510 (Mexico); Muhl, S. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Mexico D. F. 04510 (Mexico)], E-mail: muhl@servidor.unam.mx

2008-10-01

Niobium nitride (NbN) coatings have many interesting properties such as chemical inertness, excellent mechanical properties, high electrical conductivity, high melting point, and a superconducting transition temperature between 16 and 17 K. For this reason, these compounds have many potential thin film applications. In this work we compare the properties of NbN{sub x} films deposited using well-characterized balanced and unbalanced magnetron sputtering systems. Samples of NbN were deposited in the two systems under almost identical deposition conditions, that is, the same substrate temperature, plasma power, gas pressure, substrate to target distance and Ar/N{sub 2} ratio. Prior to the film preparation both the magnetic field geometry and the characteristics of the plasma were determined. The microstructure and composition of the deposits were analyzed by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The corrosion resistance and the micro-abrasion wear resistance were measured by anodic polarization potentiodynamic studies and by ball cratering, respectively. The NbN films grown using the highly unbalanced magnetron configuration had a preferential (111) crystal orientation and a composite hardness of up to 2400 HV{sub 0.025}. While the films deposited using the balanced magnetron had a mixed crystalline orientation and a hardness of 2000 HV{sub 0.025}. The results demonstrate the strong effect of magnetic field configuration on the ion bombardment, and the resultant coating characteristics.

Computer investigations of the influences of magnets for magnetron-sputtering

International Nuclear Information System (INIS)

Knotek, O.; Loeffler, F.; Schnaut, U.; Guan, W.

1993-01-01

For a long time PVD (Physical-Vapour-Deposition) technology has been applied in various modern technical fields, owing to the wide range of possible coating materials whose potential is virtually unlimited. Besides electronic, optical and decorative applications for PVD films, hard films, in particular, have been widely applied for tool coatings which play important roles for the resistance against wear and corrosion. The MSIP (Magnetron-Sputter-Ion-Plating) coating process is one of the PVD-processes, providing 1) relatively high deposition rates, 2) large deposition areas, and 3) low substrate heating. The magnetron behind the target influences the distribution of the electrons moving in the plasma and the space between the cathode and anode, thus the distribution of the ions impinging on the surface of the target. Since the electrons are distributed unevenly in front of the target, the working gas atoms are therefore unevenly ionized in the plasma and the ions also unevenly bombard the target surface and the erosion of the target surface is uneven. Therefore the investigations of the magnetic field in the MSIP are very important for the optimization of the deposition process and the usage of the target. Generally, the accurate calculations or measurements of the direction and strength of the magnetic field (magnetic induction or magnetic flux density vector B) is difficult in comparison to measurements of the electrical field, because vector B is a vector with varying direction and magnitude. In this paper, it is shown that a magnetic field of a cylindrical magnetron in MSIP-equipment can be quickly simulated through a simple model and the distribution of the field is discussed. (orig.)

Population inversion in a recombining hydrogen plasma interacting with a helium gas

International Nuclear Information System (INIS)

Oda, Toshiatsu; Furukane, Utaro.

1984-08-01

A numerical investigation has shown that the population inversion between the levels with the principal quantum number i=2 and 3 takes place in a recombining hydrogen plasma which is interacting with a cool and dense helium gas on the basis of a collisional- radiative (CR) model. Overpopulation density Δn 32 , which is defined as the difference between the population densities per unit statistical weight of the upper and lower excited levels 3 and 2, is found to be much higher than a threshold level for the laser oscillation in the quasi-steady state when the hydrogen plasma with nsub(e) = 10 13 --10 14 cm -3 interacts with the helium gas with pressure of --50 Torr. (author)

Methods of Phase and Power Control in Magnetron Transmitters for Superconducting Accelerators

Energy Technology Data Exchange (ETDEWEB)

Kazadevich, G. [MUONS Inc., Batavia; Johnson, R. [MUONS Inc., Batavia; Neubauer, M. [MUONS Inc., Batavia; Lebedev, V. [Fermilab; Schappert, W. [Fermilab; Yakovlev, V. [Fermilab

2017-05-01

Various methods of phase and power control in magnetron RF sources of superconducting accelerators intended for ADS-class projects were recently developed and studied with conventional 2.45 GHz, 1 kW, CW magnetrons operating in pulsed and CW regimes. Magnetron transmitters excited by a resonant (injection-locking) phasemodulated signal can provide phase and power control with the rates required for precise stabilization of phase and amplitude of the accelerating field in Superconducting RF (SRF) cavities of the intensity-frontier accelerators. An innovative technique that can significantly increase the magnetron transmitter efficiency at the widerange power control required for superconducting accelerators was developed and verified with the 2.45 GHz magnetrons operating in CW and pulsed regimes. High efficiency magnetron transmitters of this type can significantly reduce the capital and operation costs of the ADSclass accelerator projects.

Moment tensor inversion for two micro-earthquakes occurring inside the Haje gas storage facilities, Czech Republic

Czech Academy of Sciences Publication Activity Database

Benetatos, C.; Málek, Jiří; Verga, F.

2013-01-01

Roč. 17, č. 2 (2013), s. 557-577 ISSN 1383-4649 Institutional support: RVO:67985891 Keywords : micro-earthquake * moment-tensor inversion * gas storage * ISOLA Subject RIV: DD - Geochemistry Impact factor: 1.386, year: 2013

Double layer films based on TiO{sub 2} and NiO{sub x} for gas detection

Energy Technology Data Exchange (ETDEWEB)

Kosc, I., E-mail: ivan.kosc@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Bratislava (Slovakia); Hotovy, I. [Institute of Electronics and Photonics, Slovak University of Technology, Bratislava (Slovakia); Roch, T.; Plecenik, T.; Gregor, M. [Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava (Slovakia); Predanocy, M. [Institute of Electronics and Photonics, Slovak University of Technology, Bratislava (Slovakia); Cehlarova, M.; Kus, P.; Plecenik, A. [Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava (Slovakia)

2014-09-01

Highlights: • Double layer films based on TiO{sub 2} and NiO{sub x} for gas detection were studied. • Structural, compositional and morphological properties were investigated. • XPS spectra of TiO{sub 2} and NiO{sub x} were identified. • P- and n-type of response to hydrogen were presented. • Inversion of conductivity response type was confirmed. - Abstract: Double layer films based on TiO{sub 2} and NiO{sub x} for gas detection were studied. Two layouts with opposite position of functional films were deposited via DC magnetron sputtering method and annealed at 600 °C. The compositional, structural, morphological, electrical and gas sensing parameters were investigated. The depth profiles and the chemical state of the thin films elements were explored by X-ray photoelectron spectroscopy (XPS). Differences between the surface and subsurface NiO{sub x} were confirmed. In this way the formation of surface oxides and subsurface metallic Ni were observed. The structural changes and polycrystalline character were noticed by X-ray diffraction (XRD). The atomic force microscopy (AFM) revealed nanocrystalline character of the examined surfaces (both layouts). Different position of TiO{sub 2} and NiO{sub x} functional films brought difference in the type of response to reducing gas. Moreover, inversion of response type due to different H{sub 2} concentrations was confirmed.

The influence of carrier gas flow rate in inverse gas chromatography on the estimation of water vapor adsorption on Nylon-6 micro fiber

OpenAIRE

丸井, 正樹; 山本, 直子; 牛腸, ヒロミ; マルイ, マサキ; ヤマモト, ナオコ; ゴチョウ, ヒロミ; MASAKI, MARUI; NAOKO, YAMAMOTO; HIROMI, GOCHO

2002-01-01

The adsorption behaviors of water vapor on Nylon-6 micro fiber are measured at 90℃ with inverse gas chromatography, of which the carrier gas flow rates are 10～40ml/min. The values of retention volume decrease when the peak area is on the increase. lt indicates that Nylon-6 micro fiber has strong adsorption of water vapor at low vapor pressure. The adsorption isotherm as a whole is found to be of BET II type with certain number of adsorption sites. The gas flow rate has no effect on the estima...

Phase Grouping of Larmor Electrons by a Synchronous Wave in Controlled Magnetrons

Energy Technology Data Exchange (ETDEWEB)

Kazakevich, G. [MUONS Inc., Batavia; Johnson, R. [MUONS Inc., Batavia; Lebedev, V. [Fermilab; Yakovlev, V. [Fermilab

2018-04-01

A simplified analytical model based on the charge drift approximation has been developed. It considers the resonant interaction of the synchronous wave with the flow of Larmor electrons in a magnetron. The model predicts stable coherent generation of the tube above and below the threshold of self-excitation. This occurs if the magnetron is driven by a sufficient resonant injected signal (up to -10 dB). The model substantiates precise stability, high efficiency and low noise at the range of the magnetron power control over 10 dB by variation of the magnetron current. The model and the verifying experiments with 2.45 GHz, 1 kW magnetrons are discussed.

Geometrical Aspects of a Hollow-cathode Magnetron (HCM)

International Nuclear Information System (INIS)

Cohen, Samuel A.; Wang, Zhehui

1998-01-01

A hollow-cathode magnetron (HCM), built by surrounding a planar sputtering-magnetron cathode with a hollow-cathode structure (HCS), is operable at substantially lower pressures than its planar-magnetron counterpart. We have studied the dependence of magnetron operational parameters on the inner diameter D and length L of a cylindrical HCS. Only when L is greater than L sub zero, a critical length, is the HCM operable in the new low-pressure regime. The critical length varies with HCS inner diameter D. Explanations of the lower operational pressure regime, critical length, and plasma shape are proposed and compared with a one-dimension diffusion model for energetic or primary electron transport. At pressures above 1 mTorr, an electron-impact ionization model with Bohm diffusion at a temperature equivalent to one-half the primary electron energy and with an ambipolar constraint can explain the ion-electron pair creation required to sustain the discharge. The critical length L sub zero is determined by the magnetization length of the primary electrons

Tube Inner Coating of Non-Conductive Films by Pulsed Reactive Coaxial Magnetron Plasma with Outer Anode

Directory of Open Access Journals (Sweden)

Musab Timan Idriss Gasab

2018-03-01

Full Text Available The double-ended coaxial magnetron pulsed plasma (DCMPP method with auxiliary outer anode was introduced in order to achieve the uniform coating of non-conductive thin films on the inner walls of insulator tubes. In this study, titanium (Ti was employed as a cathode (sputtering target, and a glass tube was used as a substrate. In an argon (Ar and oxygen (O2 gas mixture, magnetron plasma was generated. Oxygen gas was introduced to deposit a titanium oxide (TiO2 film. A comparison between films coated with and without an auxiliary outer anode was made. As a result, it was clearly shown that the DCMPP method using an auxiliary outer anode enhanced the uniformity of the deposited non-conductive film compared to the conventional DCMPP method. Moreover, the optimum conditions under which the thin TiO2 film was deposited on the inner wall of the glass tube were revealed. From the results, it was supposed that the auxiliary outer anode contributed to the uniformity of the distributions of deposited negative charge on the non-conductive film and consequently the electric field and the plasma density uniform.

Inverse problem and uncertainty quantification: application to compressible gas dynamics

International Nuclear Information System (INIS)

Birolleau, Alexandre

2014-01-01

This thesis deals with uncertainty propagation and the resolution of inverse problems together with their respective acceleration via Polynomial Chaos. The object of this work is to present a state of the art and a numerical analysis of this stochastic spectral method, in order to understand its pros and cons when tackling the probabilistic study of hydrodynamical instabilities in Richtmyer-Meshkov shock tube experiments. The first chapter is introductory and allows understanding the stakes of being able to accurately take into account uncertainties in compressible gas dynamics simulations. The second chapter is both an illustrative state of the art on generalized Polynomial Chaos and a full numerical analysis of the method keeping in mind the final application on hydrodynamical problems developing shocks and discontinuous solutions. In this chapter, we introduce a new method, naming iterative generalized Polynomial Chaos, which ensures a gain with respect to generalized Polynomial Chaos, especially with non smooth solutions. Chapter three is closely related to an accepted publication in Communication in Computational Physics. It deals with stochastic inverse problems and introduces bayesian inference. It also emphasizes the possibility of accelerating the bayesian inference thanks to iterative generalized Polynomial Chaos described in the previous chapter. Theoretical convergence is established and illustrated on several test-cases. The last chapter consists in the application of the above materials to a complex and ambitious compressible gas dynamics problem (Richtmyer-Meshkov shock tube configuration) together with a deepened study of the physico-numerical phenomenon at stake. Finally, in the appendix, we also present some interesting research paths we quickly tackled during this thesis. (author) [fr

Physicochemical characterization of some solid materials by inverse gas chromatography

International Nuclear Information System (INIS)

Hamieh, T.; Abdessater, S.

2004-01-01

Full text.New equations and models on two-dimensional state of solid surfaces were previously elaborated in many other studies. results obtained were used in this paper to the determination and the quantification of some physicochemical properties of some solid surfaces, and especially, to study the acid-base superficial characteristics of some solid substrates like oxides and/or polymer adsorbed on oxides, carbon fibers, cements, etc. The technique used was the inverse gas chromatography (CGI) at infinite dilution. The acid-base constants were calculated for many solid surfaces: Al 2 O 3 , SiO 2 , MgO, ZnO, some cements, textiles and carbon fibers

A novel injection-locked amplitude-modulated magnetron at 1497 MHz

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Michael [Muons Inc., Batavia, IL (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2015-12-15

Thomas Jefferson National Accelerator Facility (JLab) uses low efficiency klystrons in the CEBAF machine. In the older portion they operate at 30% efficiency with a tube mean time between failure (MTBF) of five to six years. A highly efficient source (>55-60%) must provide a high degree of backwards compatibility, both in size and voltage requirements, to replace the klystron presently used at JLab, while providing energy savings. Muons, Inc. is developing a highly reliable, highly efficient RF source based upon a novel injection-locked amplitude modulated (AM) magnetron with a lower total cost of ownership, >80% efficiency, and MTBF of six to seven years. The design of the RF source is based upon a single injection-locked magnetron system at 8 kW capable of operating up to 13 kW, using the magnetron magnetic field to achieve the AM required for backwards compatibility to compensate for microphonics and beam loads. A novel injection-locked 1497 MHz 8 kW AM magnetron with a trim magnetic coil was designed and its operation numerically simulated during the Phase I project. The low-level RF system to control the trim field and magnetron anode voltage was designed and modeled for operation at the modulation frequencies of the microphonics. A plan for constructing a prototype magnetron and control system was developed.

Ring magnetron ionizer

International Nuclear Information System (INIS)

Alessi, J.G.

1986-01-01

A ring magnetron D - charge exchange ionizer has been built and tested. An H - current of 500 μA was extracted with an estimated H 0 density in the ionizer of 10 12 cm -3 . This exceeds the performance of ionizers presently in use on polarized H - sources. The ionizer will soon be tested with a polarized atomic beam

Microstructural variation in titanium oxide thin films deposited by DC magnetron sputtering

International Nuclear Information System (INIS)

Pandian, Ramanathaswamy; Natarajan, Gomathi; Kamruddin, M.; Tyagi, A.K.

2013-01-01

We report on the microstructural evolution of titanium oxide thin films deposited by reactive DC magnetron sputtering using titanium metal target. By varying the ratio of sputter-gas mixture containing argon, oxygen and nitrogen various phases of titanium oxide, almost pure rutile, rutile-rich and anatase-rich nano-crystalline, were deposited on Si substrates at room temperature. Using high-resolution scanning electron microscopy, X-ray diffraction and micro-Raman techniques the microstructure of the films were revealed. The relationship between the microstructure of the films and the oxygen partial pressure during sputtering is discussed

DEVICE FOR INVESTIGATION OF MAGNETRON AND PULSED-LASER PLASMA

Directory of Open Access Journals (Sweden)

A. P. Burmakov

2012-01-01

Full Text Available Various modifications of complex pulsed laser and magnetron deposition thin-film structures unit are presented. They include joint and separate variants of layer deposition. Unit realizes the plasma parameters control and enhances the possibility of laser-plasma and magnetron methods of coatings deposition.

Gas Sensor Based on 3-D WO₃ Inverse Opal: Design and Applications.

Science.gov (United States)

Xing, Ruiqing; Du, Yang; Zhao, Xiaonan; Zhang, Xiu

2017-03-29

A three-dimensional inverse opal (3DIO) WO₃ architecture has been synthesized via a simple sacrificial template method. Morphology features of the 3DIO were characterized by scanning electron microscope (SEM) and its structure was characterized by X-ray diffraction (XRD). The shrinking ratio of the PMMA spheres was ~28.2% through measuring the distribution of the PMMA spheres and 3DIO WO₃ center-to-center distance between the spheres and macropores, respectively. Beyond that, the 3DIO gas sensing properties were investigated systematically and the sensing mechanism of 3DIO WO₃ was proposed. The results indicated that the response of the 3DIO sensor possessed excellent sensitivity to acetone gas, especially at trace levels. The 3DIO gas sensor response was ~7 to 5 ppm of acetone and could detect acetone low to 0.2 ppm effectively, which was in close proximity to the theoretical low detection limit of 0.14 ppm when R a /R g ≥ 1.2 was used as the criterion for reliable gas sensing. All in all, the obvious satisfaction of the gas-sensing properties was ascribed to the structure of the 3DIO, and the sensor could be a promising novel device in the future.

Research and Development for an Alternative RF Source Using Magnetrons in CEBAF

Science.gov (United States)

Jacobs, Andrew

2016-09-01

At Jefferson Lab, klystrons are currently used as a radiofrequency (RF) power source for the 1497 MHz Continuous Electron Beam Accelerator Facility (CEBAF) Continuous Wave (CW) system. A drop-in replacement for the klystrons in the form of a system of magnetrons is being developed. The klystron DC-RF efficiency at CEBAF is 35-51% while the estimated magnetron efficiency is 80-90%. Thus, the introduction of magnetrons to CEBAF will have enormous benefits in terms of electrical power saving. The primary focus of this project was to characterize a magnetron's frequency pushing and pulling curves at 2.45 GHz with stub tuner and anode current adjustments so that a Low Level RF controller for a new 1.497 GHz magnetron can be built. A Virtual Instrument was created in LabVIEW, and data was taken. The resulting data allowed for the creation of many constant lines of frequency and output power. Additionally, the results provided a characterization of magnetron oven temperature drift over the operation time and the relationship between anode current and frequency. Using these results, the control model of different variables and their feedback or feedforward that affect the frequency pushing and pulling of the magnetron is better developed. Department of Energy, Science Undergraduate Laboratory Internships, and Jefferson Lab.

Deposition of Al/Cu Multilayer By Double Targets Cylindrical DC Magnetron Sputtering System

Directory of Open Access Journals (Sweden)

P. Balashabadi

2013-12-01

Full Text Available A cylindrical direct current magnetron sputtering coater with two targets for deposition of multilayer thin films and cermet solar selective surfaces has been constructed. The substrate holder was able to rotate around the target for obtaining the uniform layer and separated multilayer phases. The Al/ Cu multilayer film was deposited on the glass substrate at the following conditions: Working gas = Pure argon, Working pressure = 1 Pa, Cathode current = 8 A and cathode voltage = -600 V .Microstructure of the film was investigated by X-Ray Diffraction and the scanning electron microscopy analyses. The elements profile was determined by glow discharge–optical emission spectroscopy analysis. During deposition, both targets with magnetron configuration were sputtered simultaneously by argon ions. A Plasma column on the targets surface was generated by a 290 G permanent magnet unit. Two DC power supply units with three phases input and maximum output of 12 A/1000V were used to deposit the multilayer thin films. A control phase system was used to adjust output voltage.

FAST TRACK COMMUNICATION: Deposition of amino-rich thin films by RF magnetron sputtering of nylon

Science.gov (United States)

Kylián, O.; Hanuš, J.; Choukourov, A.; Kousal, J.; Slavínská, D.; Biederman, H.

2009-07-01

RF magnetron sputtering of a nylon target in different gas mixtures was studied in order to evaluate the capability of this process to deposit amino-rich coatings needed in a wide range of biomedical applications. It has been demonstrated that both the deposition rate of the coatings and the surface density of primary amino groups are strongly linked with working gas mixture composition. From this point of view, a sufficiently high deposition rate as well as the highest amine efficiency reaching a NH2/C value of 18% was observed in the N2/H2 discharge, which leads to the surface exhibiting a high rate of protein adsorption.

Inverse free electron laser beat-wave accelerator research

International Nuclear Information System (INIS)

Marshall, T.C.; Bhattacharjee, A.

1993-09-01

A calculation on the stabilization of the sideband instability in the free electron laser (FEL) and inverse FEL (IFEL) was completed. The issue arises in connection with the use of a tapered (''variable-parameter'') undulator of extended length, such as might be used in an ''enhanced efficiency'' traveling-wave FEL or an IFEL accelerator. In addition, the FEL facility at Columbia was configured as a traveling wave amplifier for a 10-kW signal from a 24-GHz magnetron. The space charge field in the bunches of the FEL was measured. Completed work has been published

Inversion Estimate of California Methane Emissions Using a Bayesian Inverse Model with Multi-Tower Greenhouse Gas Monitoring Network and Aircraft Measurements

Science.gov (United States)

Cui, Y.; Falk, M.; Chen, Y.; Herner, J.; Croes, B. E.; Vijayan, A.

2017-12-01

Methane (CH4) is an important short-lived climate pollutant (SLCP), and the second most important greenhouse gas (GHG) in California which accounts for 9% of the statewide GHG emissions inventory. Over the years, California has enacted several ambitious climate change mitigation goals, including the California Global Warming Solutions Act of 2006 which requires ARB to reduce statewide GHG emissions to 1990 emission level by 2020, as well as Assembly Bill 1383 which requires implementation of a climate mitigation program to reduce statewide methane emissions by 40% below the 2013 levels. In order to meet these requirements, ARB has proposed a comprehensive SLCP Strategy with goals to reduce oil and gas related emissions and capture methane emissions from dairy operations and organic waste. Achieving these goals will require accurate understanding of the sources of CH4 emissions. Since direct monitoring of CH4 emission sources in large spatial and temporal scales is challenging and resource intensive, we developed a complex inverse technique combined with atmospheric three-dimensional (3D) transport model and atmospheric observations of CH4 concentrations from a regional tower network and aircraft measurements, to gain insights into emission sources in California. In this study, develop a comprehensive inversion estimate using available aircraft measurements from CalNex airborne campaigns (May-June 2010) and three years of hourly continuous measurements from the ARB Statewide GHG Monitoring Network (2014-2016). The inversion analysis is conducted using two independent 3D Lagrangian models (WRF-STILT and WRF-FLEXPART), with a variety of bottom-up prior inputs from national and regional inventories, as well as two different probability density functions (Gaussian and Lognormal). Altogether, our analysis provides a detailed picture of the spatially resolved CH4 emission sources and their temporal variation over a multi-year period.

Composite SiOx/fluorocarbon plasma polymer films prepared by r.f. magnetron sputtering of SiO2 and PTFE

Czech Academy of Sciences Publication Activity Database

Pihosh, Y.; Biederman, H.; Slavínská, D.; Kousal, J.; Choukourov, A.; Trchová, Miroslava; Macková, Anna; Boldyryeva, Hanna

2006-01-01

Roč. 81, 1-4 (2006), s. 38-44 ISSN 0042-207X R&D Projects: GA MŠk OC 527.10; GA MŠk ME 553 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.834, year: 2006

Magnetron injection gun scaling

International Nuclear Information System (INIS)

Lawson, W.

1988-01-01

Existing analytic design equations for magnetron injection guns (MIG's) are approximated to obtain a set of scaling laws. The constraints are chosen to examine the maximum peak power capabilities of MIG's. The scaling laws are compared with exact solutions of the design equations and are supported by MIG simulations

Population inversion in a stationary recombining plasma

International Nuclear Information System (INIS)

Otsuka, M.

1980-01-01

Population inversion, which occurs in a recombining plasma when a stationary He plasma is brought into contact with a neutral gas, is examined. With hydrogen as a contact gas, noticeable inversion between low-lying levels of H as been found. The overpopulation density is of the order of 10 8 cm -3 , which is much higher then that (approx. =10 5 cm -3 ) obtained previously with He as a contact gas. Relations between these experimental results and the conditions for population inversion are discussed with the CR model

Life test on indigenous s-band pulsed magnetron

International Nuclear Information System (INIS)

Wanmode, Y.D.; Shrivastava, P.; Hannurkar, P.R.

1999-01-01

A 2 MW S-band pulsed magnetron has been developed under joint collaboration between CAT and CEERI. In this development effort several lab prototypes were evaluated on 2 MW microwave test facility developed at CAT. One magnetron is subjected to life test. The present paper describes the setup and procedures used for life test. Various observations and corrections made during the life tests are also described. Results of the tests are discussed. (author)

Deposition Rates of High Power Impulse Magnetron Sputtering: Physics and Economics

Energy Technology Data Exchange (ETDEWEB)

Anders, Andre

2009-11-22

Deposition by high power impulse magnetron sputtering (HIPIMS) is considered by some as the new paradigm of advanced sputtering technology, yet this is met with skepticism by others for the reported lower deposition rates, if compared to rates of more conventional sputtering of equal average power. In this contribution, the underlying physical reasons for the rate changes are discussed, including (i) ion return to the target and self-sputtering, (ii) the less-than-linear increase of the sputtering yield with increasing ion energy, (iii) yield changes due to the shift of species responsible for sputtering, (iv) changes to due to greater film density, limited sticking, and self-sputtering on the substrate, (v) noticeable power losses in the switch module, (vi) changes of the magnetic balance and particle confinement of the magnetron due to self-fields at high current, and (vii) superposition of sputtering and sublimation/evaporation for selected materials. The situation is even more complicated for reactive systems where the target surface chemistry is a function of the reactive gas partial pressure and discharge conditions. While most of these factors imply a reduction of the normalized deposition rate, increased rates have been reported for certain conditions using hot targets and less poisoned targets. Finally, some points of economics and HIPIMS benefits considered.

Deposition rates of high power impulse magnetron sputtering: Physics and economics

International Nuclear Information System (INIS)

Anders, Andre

2010-01-01

Deposition by high power impulse magnetron sputtering (HIPIMS) is considered by some as the new paradigm of advanced sputtering technology, yet this is met with skepticism by others for the reported lower deposition rates, if compared to rates of more conventional sputtering of equal average power. In this contribution, the underlying physical reasons for the rate changes are discussed, including (i) ion return to the target and self-sputtering, (ii) the less-than-linear increase in the sputtering yield with increasing ion energy, (iii) yield changes due to the shift of species responsible for sputtering, (iv) changes due to greater film density, limited sticking, and self-sputtering on the substrate, (v) noticeable power losses in the switch module, (vi) changes in the magnetic balance and particle confinement of the magnetron due to self-fields at high current, and (vii) superposition of sputtering and sublimation/evaporation for selected materials. The situation is even more complicated for reactive systems where the target surface chemistry is a function of the reactive gas partial pressure and discharge conditions. While most of these factors imply a reduction in the normalized deposition rate, increased rates have been reported for certain conditions using hot targets and less poisoned targets. Finally, some points of economics and HIPIMS benefits are considered.

Study of deposition rae coating of Ag thin films by magnetron sputtering

International Nuclear Information System (INIS)

Ghanati, M.; Zendehnam, A.

2003-01-01

Exact knowledge about deposition rate and its distribution and variation of them with respect to coating parameters (Gas pressure, Distance, discharge current,..) is very vital. In this experimental research coating of Ag thin films by magnetron sputtering have been carried out over Ar pressure range of 10 -2 -10 -1 mbar, and discharge current up to 1000 m.A, and distance between glass substrates to silver target (Cathode) was changed from 5 to 15 cm. The obtained results have been investigated by help of computer curve fitting, and these studies show a very good agreement for the conditions used in this work

Spectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas

International Nuclear Information System (INIS)

Andersson, Joakim; Ni, Pavel; Anders, André

2013-01-01

Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side-on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation

Phase and Frequency Locked Magnetrons for SRF Sources

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Michael [Muons, Inc.; Johnson, Rolland

2014-09-12

There is great potential for a magnetron power source that can be controlled both in phase and frequency. Such a power source could revolutionize many particle accelerator systems that require lower capital cost and/or higher power efficiency. Beyond the accelerator community, phase and frequency locked magnetons could improve radar systems around the world and make affordable phased arrays for wireless power transmission for solar powered satellites. This joint project of Muons, Inc., Fermilab, and L-3 CTL was supported by an STTR grant monitored by the Nuclear Physics Office of the DOE Office of Science. The object of the program was to incorporate ferrite materials into the anode of a magnetron and, with appropriate biasing of the ferrites, to maintain frequency lock and to allow for frequency adjustment of the magnetron without mechanical tuners. If successful, this device would have a dual use both as a source for SRF linacs and for military applications where fast tuning of the frequency is a requirement. In order to place the materials in the proper location, several attributes needed to be modeled. First the impact of the magnetron’s magnetic field needed to be shielded from the ferrites so that they were not saturated. And second, the magnetic field required to change the frequency of the magnetron at the ferrites needed to be shielded from the region containing the circulating electrons. ANSYS calculations of the magnetic field were used to optimize both of these parameters. Once the design for these elements was concluded, parts were fabricated and a complete test assembly built to confirm the predictions of the computer models. The ferrite material was also tested to determine its compatibility with magnetron tube processing temperatures. This required a vacuum bake out of the chosen material to determine the cleanliness of the material in terms of outgassing characteristics, and a subsequent room temperature test to verify that the characteristics of

Very low pressure high power impulse triggered magnetron sputtering

Science.gov (United States)

Anders, Andre; Andersson, Joakim

2013-10-29

A method and apparatus are described for very low pressure high powered magnetron sputtering of a coating onto a substrate. By the method of this invention, both substrate and coating target material are placed into an evacuable chamber, and the chamber pumped to vacuum. Thereafter a series of high impulse voltage pulses are applied to the target. Nearly simultaneously with each pulse, in one embodiment, a small cathodic arc source of the same material as the target is pulsed, triggering a plasma plume proximate to the surface of the target to thereby initiate the magnetron sputtering process. In another embodiment the plasma plume is generated using a pulsed laser aimed to strike an ablation target material positioned near the magnetron target surface.

Fuzzy tungsten in a magnetron sputtering device

Energy Technology Data Exchange (ETDEWEB)

Petty, T.J., E-mail: tjpetty@liv.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom); Khan, A. [Pariser Building-G11, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL (United Kingdom); Heil, T. [NiCaL, Block C Waterhouse Building, 1-3 Brownlow Street, Liverpool, L69 3GL (United Kingdom); Bradley, J.W., E-mail: j.w.bradley@liverpool.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom)

2016-11-15

Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10{sup 23}–3.0 × 10{sup 24} m{sup −2}, the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10{sup 24} m{sup −2}, and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ{sup 1/2} relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

Fuzzy tungsten in a magnetron sputtering device

International Nuclear Information System (INIS)

Petty, T.J.; Khan, A.; Heil, T.; Bradley, J.W.

2016-01-01

Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10 23 –3.0 × 10 24  m −2 , the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10 24  m −2 , and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ 1/2 relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

Gas Sensor Based on 3-D WO3 Inverse Opal: Design and Applications

Directory of Open Access Journals (Sweden)

Ruiqing Xing

2017-03-01

Full Text Available A three-dimensional inverse opal (3DIO WO3 architecture has been synthesized via a simple sacrificial template method. Morphology features of the 3DIO were characterized by scanning electron microscope (SEM and its structure was characterized by X-ray diffraction (XRD. The shrinking ratio of the PMMA spheres was ~28.2% through measuring the distribution of the PMMA spheres and 3DIO WO3 center-to-center distance between the spheres and macropores, respectively. Beyond that, the 3DIO gas sensing properties were investigated systematically and the sensing mechanism of 3DIO WO3 was proposed. The results indicated that the response of the 3DIO sensor possessed excellent sensitivity to acetone gas, especially at trace levels. The 3DIO gas sensor response was ~7 to 5 ppm of acetone and could detect acetone low to 0.2 ppm effectively, which was in close proximity to the theoretical low detection limit of 0.14 ppm when Ra/Rg ≥ 1.2 was used as the criterion for reliable gas sensing. All in all, the obvious satisfaction of the gas-sensing properties was ascribed to the structure of the 3DIO, and the sensor could be a promising novel device in the future.

Recent progress in thin film processing by magnetron sputtering with plasma diagnostics

International Nuclear Information System (INIS)

Han, Jeon G

2009-01-01

The precise control of the structure and related properties becomes crucial for sophisticated applications of thin films deposited by magnetron sputtering in emerging industries including the flat panel display, digital electronics and nano- and bio-industries. The film structure is closely related to the total energy delivered to the substrate surface for nucleation and growth during all kinds of thin film processes, including magnetron sputtering. Therefore, the energy delivered to the surface for nucleation and growth during magnetron sputtering should be measured and analysed by integrated diagnostics of the plasma parameters which are closely associated with the process parameters and other external process conditions. This paper reviews the background of thin film nucleation and growth, the status of magnetron sputtering technology and the progress of plasma diagnostics for plasma processing. The evolution of the microstructure during magnetron sputtering is then discussed with respect to the change in the process variables in terms of the plasma parameters along with empirical data of the integrated plasma diagnostics for various magnetron sputtering conditions with conventional dc, pulsed dc and high power pulsed dc sputtering modes. Among the major energy terms to be discussed are the temperature change in the top surface region and the energies of ions and neutral species. (topical review)

Understanding of hybrid PVD–PECVD process with the aim of growing hard nc-TiC/a-C:H coatings using industrial devices with a rotating cylindrical magnetron

Czech Academy of Sciences Publication Activity Database

Žemlička, R.; Jílek, M.; Vogl, P.; Souček, P.; Buršíková, V.; Buršík, Jiří; Vašina, P.

2014-01-01

Roč. 255, 25 September (2014), s. 118-123 ISSN 0257-8972 Institutional support: RVO:68081723 Keywords : nanocomposite * magnetron sputtering * process control Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.998, year: 2014

Influence of Magnetron Effect on Barium Hexaferrite Thin Layers

International Nuclear Information System (INIS)

Hassane, H.; Chatelon, J.P.; Rousseau, J.J; Siblini, A.; Kriga, A.

2011-01-01

In this paper, we study the effects of a magnet, located in the cathode, on barium hexaferrite thin films deposited by RF magnetron sputtering technique. During the process, these effects can modify thickness, roughness and stress of coatings. The characteristics of the deposited layers depend on the substrate position that is located opposite of magnetron cathode. In the m agnetron area , one can observe that the high stress can produce cracks or detachment of layers and the increasing of both depositing rate and surface roughness. After sputtering elaboration, barium hexaferrite films are in a compressive stress mode. But, after the post-deposition heat treatment these films are in a tensile stress mode. To improve the quality of BaM films, the subsrtate has to be set outside the magnetron area. (author)

Algan/Gan Hemt By Magnetron Sputtering System

Science.gov (United States)

Garcia Perez, Roman

In this thesis, the growth of the semiconductor materials AlGaN and GaN is achieved by magnetron sputtering for the fabrication of High Electron Mobility Transistors (HEMTs). The study of the deposited nitrides is conducted by spectroscopy, diffraction, and submicron scale microscope methods. The preparation of the materials is performed using different parameters in terms of power, pressure, temperature, gas, and time. Silicon (Si) and Sapphire (Al2O3) wafers are used as substrates. The chemical composition and surface topography of the samples are analyzed to calculate the materials atomic percentages and to observe the devices surface. The instruments used for the semiconductors characterization are X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscope (AFM). The project focused its attention on the reduction of impurities during the deposition, the controlled thicknesses of the thin-films, the atomic configuration of the alloy AlxGa1-xN, and the uniformity of the surfaces.

Fabrication of Ni@Ti core-shell nanoparticles by modified gas aggregation source

Science.gov (United States)

Hanuš, J.; Vaidulych, M.; Kylián, O.; Choukourov, A.; Kousal, J.; Khalakhan, I.; Cieslar, M.; Solař, P.; Biederman, H.

2017-11-01

Ni@Ti core-shell nanoparticles were prepared by a vacuum based method using the gas aggregation source (GAS) of nanoparticles. Ni nanoparticles fabricated in the GAS were afterwards coated by a Ti shell. The Ti shell was deposited by means of magnetron sputtering. The Ni nanoparticles were decelerated in the vicinity of the magnetron to the Ar drift velocity in the second deposition chamber. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy analysis of the nanoparticles showed the core-shell structure. It was shown that the thickness of the shell can be easily tuned by the process parameters with a maximum achieved thickness of the Ti shell ~2.5 nm. The core-shell structure was confirmed by the STEM analysis of the particles.

Distribution of Fe atom density in a dc magnetron sputtering plasma source measured by laser-induced fluorescence imaging spectroscopy

Science.gov (United States)

Shibagaki, K.; Nafarizal, N.; Sasaki, K.; Toyoda, H.; Iwata, S.; Kato, T.; Tsunashima, S.; Sugai, H.

2003-10-01

Magnetron sputtering discharge is widely used as an efficient method for thin film fabrication. In order to achieve the optimized fabrication, understanding of the kinetics in plasmas is essential. In the present work, we measured the density distribution of sputtered Fe atoms using laser-induced fluorescence imaging spectroscopy. A dc magnetron plasma source with a Fe target was used. An area of 20 × 2 mm in front of the target was irradiated by a tunable laser beam having a planar shape. The picture of laser-induced fluorescence on the laser beam was taken using an ICCD camera. In this way, we obtained the two-dimensional image of the Fe atom density. As a result, it has been found that the Fe atom density observed at a distance of several centimeters from the target is higher than that adjacent to the target, when the Ar gas pressure was relatively high. It is suggested from this result that some gas-phase production processes of Fe atoms are available in the plasma. This work has been performed under the 21st Century COE Program by the Ministry of Education, Culture, Sports, Science and Technology in Japan.

NOVEL TECHNIQUE OF POWER CONTROL IN MAGNETRON TRANSMITTERS FOR INTENSE ACCELERATORS

Energy Technology Data Exchange (ETDEWEB)

Kazakevich, G. [MUONS Inc., Batavia; Johnson, R. [MUONS Inc., Batavia; Neubauer, M.; Lebedev, V. [Fermilab; Schappert, W. [Fermilab; Yakovlev, V. [Fermilab

2016-10-21

A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The con- cept uses magnetrons driven by a sufficient resonant (in- jection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wide-band phase and y power controls is presented and discussed.

Nanoporous zinc oxide films prepared by magnetron sputtering

International Nuclear Information System (INIS)

Ghimpu, L.; Lupan, O.; Popescu, L.; Tiginyanu, I.M.

2011-01-01

In this paper we demonstrate an inexpensive approach for the fabrication of nanoporous zinc oxide films by using magnetron sputtering. Study of the structural properties proves the crystallographic perfection of porous nanostructures and the possibility of its controlling by adjusting the technological parameters in the growth process. The XRD pattern of nanoporous ZnO films exhibits high intensity of the peaks relative to the background signal which is indicative of the ZnO hexagonal phase and a good crystallinity of the samples grown by magnetron sputtering.

Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Straňák, V.; Hubička, Zdeněk; Čada, Martin; Bogdanowicz, R.; Wulff, H.; Helm, C.A.; Hippler, R.

2018-01-01

Roč. 51, č. 9 (2018), s. 1-12, č. článku 095205. ISSN 0022-3727 R&D Projects: GA ČR GA17-08389S Institutional support: RVO:68378271 Keywords : high power impulse magnetron sputtering (HiPIMS) * iron oxide thin films * wüstite * magnetite * maghemite * hematite Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics ) Impact factor: 2.588, year: 2016

An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources

Energy Technology Data Exchange (ETDEWEB)

Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Silze, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

2014-05-15

An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10{sup 10} cm{sup −3} to 1 × 10{sup 11} cm{sup −3}, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10{sup 18} atoms/s for aluminum, which meets the demand for the production of a milliampere Al{sup +} ion beam.

Characterization of nanocarbons (nanotubes and nanofibers) by Inverse Gas Chromatography

Energy Technology Data Exchange (ETDEWEB)

DIaz, E [Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julian ClaverIa s/n, 33006 Oviedo (Spain); Ordonez, S [Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julian ClaverIa s/n, 33006 Oviedo (Spain); Vega, A [Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julian ClaverIa s/n, 33006 Oviedo (Spain)

2007-04-15

The adsorption of different alkanes (linear and cyclic), aromatics and chlorohydrocarbons on non-microporous carbons-carbon nanotubes (CNTs) and carbon nanofibres (CNFs)- was studied in this work by inverse gas chromatography (IGC). Capacity of adsorption was derived from the isotherms of adsorption, whereas thermodynamic properties (enthalpy of adsorption, surface free energy characteristics) have been determined from chromatographic retention data. CNTs present the highest adsorption capacity. From surface free energy data, enthalpies of adsorption of polar compounds were divided into dispersive and specific contributions. The interactions of cyclic (benzene and cyclohexane) and chlorinated compounds (trichloroethylene, tetrachloroethylene and chloroform) with the surfaces are mainly dispersive over all the carbons tested, being CNTs the material with the highest dispersive contribution. Adsorption parameters were correlated with morphological and chemical properties of the materials.

Characteristics of ZnO/diamond thin films prepared by RF magnetron sputtering

CERN Document Server

Park, Y W; Lee, J G; Baik, Y J; Kim, H J; Jung, H J; Choi, W K; Cho, B H; Park, C Y

1999-01-01

Due to its high Young's modulus, diamond has the highest acoustic wave velocity among all materials and is expected to be a candidate substrate for high-frequency surface acoustic wave(SAW) devices. In this study, the deposition of ZnO, as a piezoelectric layer, on a diamond substrate is investigated. ZnO has been fabricated by using RF magnetron sputtering with a ZnO target and various Ar/O sub 2 gas ratios, RF powers, and substrate temperatures at a vacuum of 10 sup - sup 5 Torr. The sputtered ZnO films are characterized by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS), and I-V characteristics. All the films show only a (002) orientation. The atomic concentration of the sputtered ZnO films is changed by the oxygen gas ratio, and the ZnO films are grown with a homogeneous composition over their entire thickness. The electrical resistivity of the films varied from 4x10 sup 3 to 7x10 sup 8 OMEGA cm, depending on the Ar/O sub 2 gas ratio. The phase...

Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lin, M.-C. [Department of Materials Science and Engineering, National ChungHsin University, 250, Kuo-Kung Road, 40227 Taichung, Taiwan (China); Chang, L.-S. [Department of Materials Science and Engineering, National ChungHsin University, 250, Kuo-Kung Road, 40227 Taichung, Taiwan (China)], E-mail: lschang@dragon.nchu.edu.tw; Lin, H.C. [Department of Materials Science and Engineering, National Taiwan University, 1, Roosevelt Road, Sec. 4, 106 Taipei, Taiwan (China)

2008-03-30

Titanium oxynitride (TiN{sub x}O{sub y}) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiN{sub x}O{sub y} films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm{sup 2} to 7 W/cm{sup 2}. The maximum deposition rate occurs, as the substrate bias is -40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiN{sub x}O{sub y} films deposited at power densities above 4 W/cm{sup 2} show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiN{sub x}O{sub y} films reach values as low as 0.98 g/m{sup 2}-day-atm and 0.60 cm{sup 3}/m{sup 2}-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al{sub 2}O{sub 3} barrier films. Therefore, TiN{sub x}O{sub y} films are potential candidates to be used as a gas permeation barrier for PET substrate.

Substrate heating and cooling during magnetron sputtering of copper target

Energy Technology Data Exchange (ETDEWEB)

Shapovalov, Viktor I.; Komlev, Andrey E.; Bondarenko, Anastasia S., E-mail: stopnastia@gmail.com; Baykov, Pavel B.; Karzin, Vitaliy V.

2016-02-22

Heating and cooling processes of the substrate during the DC magnetron sputtering of the copper target were investigated. The sensitive element of a thermocouple was used as a substrate. It was found, that the heat outflow rate from the substrate is lower when the magnetron is turned off rather than when it is turned on. Furthermore, the heating rate, the ultimate temperature, and the heat outflow rate related to the deposition of copper atoms are directly proportional to the discharge current density. - Highlights: • New effect of heat outflow from substrate when magnetron is on was discovered. • This new effect is linear in terms of heat outflow rate to target current ratio. • Kinetic equation for heating process additively considers this effect.

Variable Power, Short Microwave Pulses Generation using a CW Magnetron

Directory of Open Access Journals (Sweden)

CIUPA, R.

2011-05-01

Full Text Available Fine control of microwave power radiation in medical and scientific applications is a challenging task. Since a commercial Continuous Wave (CW magnetron is the most inexpensive microwave device available today on the market, it becomes the best candidate for a microwave power generator used in medical diathermy and hyperthermia treatments or high efficiency chemical reactions using microwave reactors as well. This article presents a new method for driving a CW magnetron with short pulses, using a modified commercial Zero Voltage Switching (ZVS inverter, software driven by a custom embedded system. The microwave power generator designed with this method can be programmed for output microwave pulses down to 1% of the magnetron's power and allows microwave low frequency pulse modulation in the range of human brain electrical activity, intended for medical applications. Microwave output power continuous control is also possible with the magnetron running in the oscillating area, using a dual frequency Pulse Width Modulation (PWM, where the low frequency PWM pulse is modulating a higher resonant frequency required by the ZVS inverter's transformer. The method presented allows a continuous control of both power and energy (duty-cycle at the inverter's output.

Inverse Magnetoresistance in Polymer Spin Valves.

Science.gov (United States)

Ding, Shuaishuai; Tian, Yuan; Li, Yang; Mi, Wenbo; Dong, Huanli; Zhang, Xiaotao; Hu, Wenping; Zhu, Daoben

2017-05-10

In this work, both negative and positive magnetoresistance (MR) in solution-processed regioregular poly(3-hexylthiophene) (RR-P3HT) is observed in organic spin valves (OSVs) with vertical La 2/3 Sr 1/3 MnO 3 (LSMO)/P3HT/AlO x /Co configuration. The ferromagnetic (FM) LSMO electrode with near-atomic flatness is fabricated by a DC facing-target magnetron sputtering method. This research is focused on the origin of the MR inversion. Two types of devices are investigated in details: One with Co penetration shows a negative MR of 0.2%, while the other well-defined device with a nonlinear behavior has a positive MR of 15.6%. The MR measurements in LSMO/AlO x /Co and LSMO/Co junctions are carried to exclude the interference of insulating layer and two FM electrodes themselves. By examining the Co thicknesses and their corresponding magnetic hysteresis loops, a spin-dependent hybrid-interface-state model by Co penetration is induced to explain the MR sign inversion. These results proven by density functional theory (DFT) calculations may shed light on the controllable interfacial properties in designing novel OSV devices.

A Plasma Lens for Magnetron Sputtering

International Nuclear Information System (INIS)

Anders, Andre; Brown, Jeff

2010-01-01

A plasma lens, consisting of a solenoid and potential-defining ring electrodes, has been placed between a magnetron and substrates to be coated. Photography reveals qualitative information on excitation, ionization, and the transport of plasma to the substrate.

Dielectric properties of DC reactive magnetron sputtered Al2O3 thin films

International Nuclear Information System (INIS)

Prasanna, S.; Mohan Rao, G.; Jayakumar, S.; Kannan, M.D.; Ganesan, V.

2012-01-01

Alumina (Al 2 O 3 ) thin films were sputter deposited over well-cleaned glass and Si substrates by DC reactive magnetron sputtering under various oxygen gas pressures and sputtering powers. The composition of the films was analyzed by X-ray photoelectron spectroscopy and an optimal O/Al atomic ratio of 1.59 was obtained at a reactive gas pressure of 0.03 Pa and sputtering power of 70 W. X-ray diffraction results revealed that the films were amorphous until 550 °C. The surface morphology of the films was studied using scanning electron microscopy and the as-deposited films were found to be smooth. The topography of the as-deposited and annealed films was analyzed by atomic force microscopy and a progressive increase in the rms roughness of the films from 3.2 nm to 4.53 nm was also observed with increase in the annealing temperature. Al-Al 2 O 3 -Al thin film capacitors were then fabricated on glass substrates to study the effect of temperature and frequency on the dielectric property of the films. Temperature coefficient of capacitance, AC conductivity and activation energy were determined and the results are discussed. - Highlights: ► Al 2 O 3 thin films were deposited by DC reactive magnetron sputtering. ► The films were found to be amorphous up to annealing temperature of 550 C. ► An increase in rms roughness of the films was observed with annealing. ► Al-Al 2 O 3 -Al thin film capacitors were fabricated and dielectric constant was 7.5. ► The activation energy decreased with increase in frequency.

Reactive magnetron sputtering of N-doped carbon thin films on quartz glass for transmission photocathode applications

Science.gov (United States)

Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Sasinková, V.; Boháček, P.; Arbet, J.

2018-03-01

N-doped carbon thin films were deposited on a silicon substrate and quartz glass by RF reactive magnetron sputtering using a carbon target and an Ar+N2 gas mixture. During the magnetron sputtering, the substrate holder temperatures was kept at 800 °C. The carbon film thickness on the silicon substrate was about 70 nm, while on the quartz glass it was in the range 15 nm – 60 nm. The elemental concentration in the films was determined by RBS and ERD. Raman spectroscopy was used to evaluate the intensity ratios I D/I G of the D and G peaks of the carbon films. The transmission photocathodes prepared were placed in the hollow-cathode assembly of a Pierce-structure DC gun to produce photoelectrons. The quantum efficiency (QE) was calculated from the laser energy and cathode charge measured. The properties of the transmission photocathodes based on semitransparent N-doped carbon thin films on quartz glass and their potential for application in DC gun technology are discussed.

Recent advances in Pt coating of microspheres by a batch magnetron sputtering process

International Nuclear Information System (INIS)

Hsieh, E.J.; Meyer, S.F.

1980-01-01

Some proposed inertial confinement fusion targets require high-Z, high density metal coatings on glass microspheres. Platinum, which satisfies the high-Z and density requirements, can be coated onto microspheres with a batch magnetron sputtering process incorporating oxygen as a dopant gas to prevent the microspheres from sticking. This paper outlines recent progress in three areas: First, the coating process has been improved; second, the oxygen content and resistivity of the oxygen doped platinum films are analyzed; and third, the roles oxygen may play in reducing microsphere sticking during sputtering are discussed in regard to cold welding, Van der Waals bonding, electrostatic sticking, and sintering

On the control of deposition process for enhanced mechanical properties of nc-TiC/a-C: H coatings with DC magnetron sputtering at low or high ion flux

Czech Academy of Sciences Publication Activity Database

Souček, P.; Schmidtová, T.; Zábranský, L.; Buršíková, V.; Vašina, P.; Caha, O.; Buršík, Jiří; Peřina, Vratislav; Mikšová, Romana; Pei, Y.; de Hosson, J. T. M.

Roč. 255, 25 September (2014), s. 8-14 ISSN 0257-8972 Institutional support: RVO:68081723 ; RVO:61389005 Keywords : enhanced mechanical properties * ion flux on the substrate * magnetron sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.998, year: 2014

Geometrical aspects of a hollow-cathode planar magnetron

International Nuclear Information System (INIS)

Wang, Z.; Cohen, S.A.

1999-01-01

A hollow-cathode planar magnetron (HCPM), built by surrounding a planar sputtering-magnetron cathode with a hollow-cathode structure (HCS) [Z. Wang and S. A. Cohen, J. Vac. Sci. Technol. A 17, 77 (1999)], is operable at substantially lower pressures than its planar-magnetron counterpart. HCPM operational parameters depend on the inner diameter D and length L of its cylindrical HCS. Only when L is greater than L 0 , a critical length, is the HCPM operable in the new low-pressure regime. The critical length varies with HCS inner diameter D. Explanations of the lower operational pressure regime, critical length, and plasma shape are proposed and compared with a one-dimension diffusion model for energetic electron transport. At pressures above 1 mTorr, Bohm diffusion (temperature congruent primary electron energy), with an ambipolar constraint, can explain the ion - electron pair creation required to sustain the discharge. At the lowest pressure, ∼0.3 mTorr, collision-limited diffusion creates fewer ion - electron pairs than required for steady state and therefore cannot explain the experimental data. The critical length L 0 is consistent with the magnetization length of the primary electrons. copyright 1999 American Institute of Physics

Reducing errors in aircraft atmospheric inversion estimates of point-source emissions: the Aliso Canyon natural gas leak as a natural tracer experiment

Science.gov (United States)

Gourdji, S. M.; Yadav, V.; Karion, A.; Mueller, K. L.; Conley, S.; Ryerson, T.; Nehrkorn, T.; Kort, E. A.

2018-04-01

Urban greenhouse gas (GHG) flux estimation with atmospheric measurements and modeling, i.e. the ‘top-down’ approach, can potentially support GHG emission reduction policies by assessing trends in surface fluxes and detecting anomalies from bottom-up inventories. Aircraft-collected GHG observations also have the potential to help quantify point-source emissions that may not be adequately sampled by fixed surface tower-based atmospheric observing systems. Here, we estimate CH4 emissions from a known point source, the Aliso Canyon natural gas leak in Los Angeles, CA from October 2015–February 2016, using atmospheric inverse models with airborne CH4 observations from twelve flights ≈4 km downwind of the leak and surface sensitivities from a mesoscale atmospheric transport model. This leak event has been well-quantified previously using various methods by the California Air Resources Board, thereby providing high confidence in the mass-balance leak rate estimates of (Conley et al 2016), used here for comparison to inversion results. Inversions with an optimal setup are shown to provide estimates of the leak magnitude, on average, within a third of the mass balance values, with remaining errors in estimated leak rates predominantly explained by modeled wind speed errors of up to 10 m s‑1, quantified by comparing airborne meteorological observations with modeled values along the flight track. An inversion setup using scaled observational wind speed errors in the model-data mismatch covariance matrix is shown to significantly reduce the influence of transport model errors on spatial patterns and estimated leak rates from the inversions. In sum, this study takes advantage of a natural tracer release experiment (i.e. the Aliso Canyon natural gas leak) to identify effective approaches for reducing the influence of transport model error on atmospheric inversions of point-source emissions, while suggesting future potential for integrating surface tower and

Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

Energy Technology Data Exchange (ETDEWEB)

Hänninen, Tuomas, E-mail: tuoha@ifm.liu.se; Schmidt, Susann; Jensen, Jens; Hultman, Lars; Högberg, Hans [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden)

2015-09-15

Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.

Magnetron with smooth anode. Statistical theory and ordered oscillations; Magnetron a anode lisse. Theorie statistique et oscillations ordonnees

Energy Technology Data Exchange (ETDEWEB)

Coste, J.

1961-03-15

We have to investigate the equilibrium regime that appears between a hot cathode and the electronic cloud that is confined around the cathode by a magnetic field parallel to its axis. The densities being high enough to involve the effect of space charge. The challenge of the magnetron theory is to face 2 issues: first the structure of the electronic cloud in a diode submitted to a magnetic field and secondly the oscillations that are likely to appear in this cloud. In this work we have made 2 attempts to clarify the situation, we have extended the classical theory of the static charge of space through a study of its oscillation modes on one hand and on the other hand we have tackled the issue of the structure of the electronic cloud with the tool of statistics. This document is divided into 2 chapters. In the first chapter we present a static study of the magnetron in which we take a statistical approach deliberately. We give answers to the issue of the thermodynamical equilibrium of the electronic cloud and we have found a mode very close to the Brillouin mode. The statistical approach has made us discuss the boundary conditions on the cathode, it means the coupling between the cathode and the electronic cloud. In the second chapter we present the theoretical study of the oscillations in a magnetron operating in the Brillouin mode. The resonances that appear in experimental data stay difficult to explain.

Control and enhancement of the oxygen storage capacity of ceria films by variation of the deposition gas atmosphere during pulsed DC magnetron sputtering

Science.gov (United States)

Eltayeb, Asmaa; Vijayaraghavan, Rajani K.; McCoy, Anthony; Venkatanarayanan, Anita; Yaremchenko, Aleksey A.; Surendran, Rajesh; McGlynn, Enda; Daniels, Stephen

2015-04-01

In this study, nanostructured ceria (CeO2) films are deposited on Si(100) and ITO coated glass substrates by pulsed DC magnetron sputtering using a CeO2 target. The influence on the films of using various gas ambients, such as a high purity Ar and a gas mixture of high purity Ar and O2, in the sputtering chamber during deposition are studied. The film compositions are studied using XPS and SIMS. These spectra show a phase transition from cubic CeO2 to hexagonal Ce2O3 due to the sputtering process. This is related to the transformation of Ce4+ to Ce3+ and indicates a chemically reduced state of CeO2 due to the formation of oxygen vacancies. TGA and electrochemical cyclic voltammetry (CV) studies show that films deposited in an Ar atmosphere have a higher oxygen storage capacity (OSC) compared to films deposited in the presence of O2. CV results specifically show a linear variation with scan rate of the anodic peak currents for both films and the double layer capacitance values for films deposited in Ar/O2 mixed and Ar atmosphere are (1.6 ± 0.2) × 10-4 F and (4.3 ± 0.5) × 10-4 F, respectively. Also, TGA data shows that Ar sputtered samples have a tendency to greater oxygen losses upon reduction compared to the films sputtered in an Ar/O2 mixed atmosphere.

Determination of the sputter rate variation pattern of a silicon carbide target for radio frequency magnetron sputtering using optical transmission measurements

International Nuclear Information System (INIS)

Galvez de la Puente, G.; Guerra Torres, J.A.; Erlenbach, O.; Steidl, M.; Weingaertner, R.; De Zela, F.; Winnacker, A.

2010-01-01

We produce amorphous silicon carbide thin films (a-SiC) by radio frequency (rf) magnetron sputtering from SiC bulk target. We present the emission pattern of the rf magnetron with SiC target as a function of process parameters, like target sample distance, rf power, sputtering rate and process gas pressure. The emission pattern is determined by means of thickness distribution of the deposited a-SiC films obtained from optical transmission measurements using a slightly improved method of Swanepoel concerning the determination of construction of the envelopes in the interference pattern of the transmission spectra. A calibration curve is presented which allows the conversion of integrated transmission to film thickness. Holding constant a set of process parameters and only varying the target sample distance the emission pattern of the rf magnetron with SiC target was determined, which allowed us to predict the deposition rate distribution for a wide range of process parameters and target geometry. In addition, we have found that the transmission spectra of the a-SiC films change with time and saturate after approximately 10 days. Within this process no change in thickness is involved, so that the determination of thickness using transmission data is justified.

High-current magnetron discharge with magnetic insulation of anode

International Nuclear Information System (INIS)

Bizyukov, A.A.; Sereda, K.N.; Sleptsov, V.V.

2008-01-01

In magnetron discharge at currents higher then critical which magnitude is in the range of 15...30 A the transition from glow discharge in transverse magnetic field to arc discharge occurs. In the present time the problem of arc blowout is solved at the expense of pulse and HF power supply applying. In this paper the alternative method of limiting current of magnetron discharge increasing at the expense of increasing of discharge gap resistance by means of additional anode layer transverse magnetic field and arc current interruption by sectioning of current collector of anode surface is carrying out

Development of nanocrystalline Indium Tin Oxide (ITO) thin films using RF-magnetron sputtering

International Nuclear Information System (INIS)

Tamilselvan, N.; Thilakan, Periyasamy

2013-01-01

ITO thin films have been deposited on glass substrate using RF Magnetron puttering Technique from the pre-synthesized ITO target. The sputtering parameters such as the deposition temperature, gas composition and the RF power densities were varied. X-ray diffraction studies revealed that the crystallization of the films is mostly depending on the RF power density and substrate temperature. Crystallized films exhibited a change in the preferred orientation from (111) plane to (100) plane at specific conditions such as high RF power density and high oxygen mixing to the plasma. Change in the film microstructure and a shift in the optical bandgap were recorded from the SEM and UV-Visible measurements respectively. (author)

Composite SiO.sub.x./sub./hydrocarbon plasma polymer films prepared by RF magnetron sputtering of SiO.sub.2./sub. and polyethylene or polypropylene

Czech Academy of Sciences Publication Activity Database

Pihosh, Y.; Biederman, H.; Slavínská, D.; Kousal, J.; Choukourov, A.; Trchová, Miroslava; Macková, Anna; Boldyryeva, Hanna

2006-01-01

Roč. 81, 1-4 (2006), s. 32-37 ISSN 0042-207X R&D Projects: GA MŠk 1P05ME754 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.834, year: 2006

Commissioning of indigenous microwave test facility for development and pilot production of 2 MW S-band magnetrons

International Nuclear Information System (INIS)

Shrivastava, Purushottam; Wanmode, Y.D.; Hannurkar, P.R.; Prasad, Sharda

2005-01-01

To have self reliance in the field of microwave devices and to have consistent supply of pulsed magnetrons for the Indian accelerator programme. CAT initiated development of 2 MW S-Band pulsed magnetrons in collaboration with CEERI, Pilani. The design, development and testing of the microwave test facilities for ageing. conditioning and performance testing of Indian magnetrons, was successfully done by CAT indigenously. After the rigorous testing. the test facility was shifted, installed and commissioned at CEERI, Pilani by CAT. Over a period of 10 years, nine prototypes were aged and tested, two magnetrons were life tested and five magnetrons under production programme have been successfully conditioned and tested. Testing of more numbers is underway. The system details. commissioning aspects are discussed, results are shown. (author)

Plasma diagnostics during magnetron sputtering of aluminum doped zinc oxide

DEFF Research Database (Denmark)

Stamate, Eugen; Crovetto, Andrea; Sanna, Simone

2016-01-01

Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity of the f......Plasma parameters during magnetron sputtering of aluminum-doped zinc oxide are investigated with optical emission spectroscopy, electrostatic probes and mass spectrometry with the aim of understanding the role of negative ions of oxygen during the film growth and improving the uniformity...

Dependence of the constitution, microstructure and electrochemical behaviour of magnetron sputtered Li-Ni-Mn-Co-O thin film cathodes for lithium-ion batteries on the working gas pressure and annealing conditions

International Nuclear Information System (INIS)

Strafela, Marc; Fischer, Julian; Leiste, Harald; Rinke, Monika; Bergfeldt, Thomas; Seifert, Hans Juergen; Ulrich, Sven; Music, Denis; Chang, Keke; Schneider, Jochen

2017-01-01

Li(Ni 1/3 Mn 1/3 Co 1/3 )O 2 as a cathode material for lithium ion batteries shows good thermal stability, high reversible capacity (290 mAh g -1 ), good rate capability and better results in terms of environmental friendliness. In this paper thin film cathodes in the material system Li-Ni-Mn-Co-O were deposited onto silicon and stainless steel substrates, by non-reactive r.f. magnetron sputtering from a ceramic Li 1.18 (Ni 0.39 Mn 0.19 Co 0.35 )O 1.97 target at various argon working gas pressures between 0.2 Pa and 20 Pa. A comprehensive study on the composition and microstructure was carried out. The results showed that the elemental composition varies depending on argon working gas pressure. The elemental composition was determined by inductively coupled plasma optical emission spectroscopy in combination with carrier gas hot extraction. The films showed different grain orientations depending argon working gas pressures. The degree of cation order in the lattice structure of the films deposited at 0.5 Pa and 7 Pa argon working gas pressure, was increased by annealing in an argon/oxygen atmosphere at different pressures for one hour. The microstructure of the films varies with annealing gas pressure and is characterized using X-ray diffraction and unpolarized micro-Raman spectroscopy at room temperature. Electrochemical characterization of as-deposited and annealed films was carried out by galvanostatic cycling in Li-Ni-Mn-Co-O half-cells against metallic lithium. Correlations between process parameters, constitution, microstructure and electrochemical behaviour are discussed in detail.

Estimation of Gas Hydrate Saturation Using Constrained Sparse Spike Inversion: Case Study from the Northern South China Sea

Directory of Open Access Journals (Sweden)

Xiujuan Wang

2006-01-01

Full Text Available Bottom-simulating reflectors (BSRs were observed beneath the seafloor in the northern continental margin of the South China Sea (SCS. Acoustic impedance profile was derived by Constrained Sparse Spike Inversion (CSSI method to provide information on rock properties and to estimate gas hydrate or free gas saturations in the sediments where BSRs are present. In general, gas hydrate-bearing sediments have positive impedance anomalies and free gas-bearing sediments have negative impedance anomalies. Based on well log data and Archie's equation, gas hydrate saturation can be estimated. But in regions where well log data is not available, a quantitative estimate of gas hydrate or free gas saturation is inferred by fitting the theoretical acoustic impedance to sediment impedance obtained by CSSI. Our study suggests that gas hydrate saturation in the Taixinan Basin is about 10 - 20% of the pore space, with the highest value of 50%, and free gas saturation below BSR is about 2 - 3% of the pore space, that can rise to 8 - 10% at a topographic high. The free gas is non-continuous and has low content in the southeastern slope of the Dongsha Islands. Moreover, BSR in the northern continental margin of the SCS is related to the presence of free gas. BSR is strong where free gas occurs.

Charging of nanoparticles in stationary plasma in a gas aggregation cluster source

Science.gov (United States)

Blažek, J.; Kousal, J.; Biederman, H.; Kylián, O.; Hanuš, J.; Slavínská, D.

2015-10-01

Clusters that grow into nanoparticles near the magnetron target of the gas aggregation cluster source (GAS) may acquire electric charge by collecting electrons and ions or through other mechanisms like secondary- or photo-electron emissions. The region of the GAS close to magnetron may be considered as stationary plasma. The steady state charge distribution on nanoparticles can be determined by means of three possible models—fluid model, kinetic model and model employing Monte Carlo simulations—of cluster charging. In the paper the mathematical and numerical aspects of these models are analyzed in detail and close links between them are clarified. Among others it is shown that Monte Carlo simulation may be considered as a particular numerical technique of solving kinetic equations. Similarly the equations of the fluid model result, after some approximation, from averaged kinetic equations. A new algorithm solving an in principle unlimited set of kinetic equations is suggested. Its efficiency is verified on physical models based on experimental input data.

Electron relaxation properties of Ar magnetron plasmas

Science.gov (United States)

Xinjing, CAI; Xinxin, WANG; Xiaobing, ZOU

2018-03-01

An understanding of electron relaxation properties in plasmas is of importance in the application of magnetrons. An improved multi-term approximation of the Boltzmann equation is employed to study electron transport and relaxation properties in plasmas. Elastic, inelastic and nonconservative collisions between electrons and neutral particles are considered. The expressions for the transport coefficients are obtained using the expansion coefficients and the collision operator term. Numerical solutions of the matrix equations for the expansion coefficients are also investigated. Benchmark calculations of the Reid model are presented to demonstrate the accuracy of the improved multi-term approximation. It is shown that the two-term approximation is generally not accurate enough and the magnetic fields can reduce the anisotropy of the velocity distribution function. The electron relaxation properties of Ar plasmas in magnetrons for various magnetic fields are studied. It is demonstrated that the energy parameters change more slowly than the momentum parameters.

Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering

Science.gov (United States)

Stranak, V.; Hubicka, Z.; Cada, M.; Bogdanowicz, R.; Wulff, H.; Helm, C. A.; Hippler, R.

2018-03-01

Iron oxide films were deposited using high power impulse magnetron sputtering (HiPIMS) of an iron cathode in an argon/oxygen gas mixture at different gas pressures (0.5 Pa, 1.5 Pa, and 5.0 Pa). The HiPIMS system was operated at a repetition frequency f  =  100 Hz with a duty cycle of 1%. A main goal is a comparison of film growth during conventional and electron cyclotron wave resonance-assisted HiPIMS. The deposition plasma was investigated by means of optical emission spectroscopy and energy-resolved mass spectrometry. Active oxygen species were detected and their kinetic energy was found to depend on the gas pressure. Deposited films were characterized by means of spectroscopic ellipsometry and grazing incidence x-ray diffraction. Optical properties and crystallinity of as-deposited films were found to depend on the deposition conditions. Deposition of hematite iron oxide films with the HiPIMS-ECWR discharge is attributed to the enhanced production of reactive oxygen species.

A Compact, Pi-Mode Extraction Scheme for the Axial B-Field Recirculating Planar Magnetron

Science.gov (United States)

2012-07-23

Figure 4). Thus, in a planar magnetron, the minimum phase velocity, vph , to stay above cutoff in the rectangular waveguide is ℎ = ...as magnetrons, electrons must be accelerated such that they are in synchronism with the phase velocity, vph , of the electromagnetic wave for an

Physics and phenomena in pulsed magnetrons: an overview

International Nuclear Information System (INIS)

Bradley, J W; Welzel, T

2009-01-01

This paper reviews the contribution made to the observation and understanding of the basic physical processes occurring in an important type of magnetized low-pressure plasma discharge, the pulsed magnetron. In industry, these plasma sources are operated typically in reactive mode where a cathode is sputtered in the presence of both chemically reactive and noble gases typically with the power modulated in the mid-frequency (5-350 kHz) range. In this review, we concentrate mostly, however, on physics-based studies carried out on magnetron systems operated in argon. This simplifies the physical-chemical processes occurring and makes interpretation of the observations somewhat easier. Since their first recorded use in 1993 there have been more than 300 peer-reviewed paper publications concerned with pulsed magnetrons, dealing wholly or in part with fundamental observations and basic studies. The fundamentals of these plasmas and the relationship between the plasma parameters and thin film quality regularly have whole sessions at international conferences devoted to them; however, since many different types of magnetron geometries have been used worldwide with different operating parameters the important results are often difficult to tease out. For example, we find the detailed observations of the plasma parameter (particle density and temperature) evolution from experiment to experiment are at best difficult to compare and at worst contradictory. We review in turn five major areas of studies which are addressed in the literature and try to draw out the major results. These areas are: fast electron generation, bulk plasma heating, short and long-term plasma parameter rise and decay rates, plasma potential modulation and transient phenomena. The influence of these phenomena on the ion energy and ion energy flux at the substrate is discussed. This review, although not exhaustive, will serve as a useful guide for more in-depth investigations using the referenced

UV-Enhanced Ethanol Sensing Properties of RF Magnetron-Sputtered ZnO Film.

Science.gov (United States)

Huang, Jinyu; Du, Yu; Wang, Quan; Zhang, Hao; Geng, Youfu; Li, Xuejin; Tian, Xiaoqing

2017-12-26

ZnO film was deposited by the magnetron sputtering method. The thickness of ZnO film is approximately 2 μm. The influence of UV light illumination on C₂H₅OH sensing properties of ZnO film was investigated. Gas sensing results revealed that the UV-illuminated ZnO film displays excellent C₂H₅OH characteristics in terms of high sensitivity, excellent selectivity, rapid response/recovery, and low detection limit down to 0.1 ppm. The excellent sensing performance of the sensor with UV activation could be attributed to the photocatalytic oxidation of ethanol on the surface of the ZnO film, the planar film structure with high utilizing efficiency of UV light, high electron mobility, and a good surface/volume ratio of of ZnO film with a relatively rough and porous surface.

Structural and thermal properties of nanocrystalline CuO synthesized by reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Verma, M. [Department of Chemistry, IIT Roorkee, Roorkee-247667, India and Nano Science Laboratory, Institute Instrumentation Centre, IIT Roorkee, Roorkee-247667 (India); Gupta, V. K. [Department of Chemistry, IIT Roorkee, Roorkee-247667 (India); Gautam, Y. K.; Dave, V.; Chandra, R. [Nano Science Laboratory, Institute Instrumentation Centre, IIT Roorkee, Roorkee-247667 (India)

2014-01-28

Recent research has shown immense application of metal oxides like CuO, MgO, CaO, Al{sub 2}O{sub 3}, etc. in different areas which includes chemical warfare agents, medical drugs, magnetic storage media and solar energy transformation. Among the metal oxides, CuO nanoparticles are of special interest because of their excellent gas sensing and catalytic properties. In this paper we report structural and thermal properties of CuO synthesized by reactive magnetron DC sputtering. The synthesized nanoparticles were characterized by X-ray diffractometer. The XRD result reveals that as DC power increased from 30W to 80W, size of the CuO nanoparticles increased. The same results have been verified through TEM analysis. Thermal properties of these particles were studied using thermogravimetry.

First demonstration and performance of an injection locked continuous wave magnetron to phase control a superconducting cavity

Directory of Open Access Journals (Sweden)

A. C. Dexter

2011-03-01

Full Text Available The applications of magnetrons to high power proton and cw electron linacs are discussed. An experiment is described where a 2.45 GHz magnetron has been used to drive a single cell superconducting cavity. With the magnetron injection locked, a modest phase control accuracy of 0.95° rms has been demonstrated. Factors limiting performance have been identified.

Characterization and Optimization of the Magnetron Directional Amplifier

National Research Council Canada - National Science Library

Hatfield, Michael

1999-01-01

.... A conventional microwave oven magnetron may be converted into a two-port amplifier capable of delivering over 30 dB of gain, while remaining phase-locked to the input signal over a wide frequency range...

Mass spectrometric characterizations of ions generated in RF magnetron discharges during sputtering of silver in Ne, Ar, Kr and Xe gases

Czech Academy of Sciences Publication Activity Database

Pokorný, D.; Novotný, Michal; Musil, Jindřich; Fitl, Přemysl; Bulíř, Jiří; Lančok, Ján

2013-01-01

Roč. 10, č. 7 (2013), s. 593-602 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR(CZ) GAP108/11/1312; GA ČR(CZ) GAP108/11/0958 Grant - others:AVČR(CZ) M100101271 Institutional support: RVO:68378271 Keywords : double charge ions * mass spectrometry * noble gas * RF magnetron discharges * silver * single charge ions Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.964, year: 2013

The Development and Application of the Magnetron,

Science.gov (United States)

1982-03-31

of *medicine. The power of the magnetron used is from several tens of watts to several hundred watts. Microwave physiotherapy has been used in...clinical practice for the fast cure of arthritis , rheumatism and the subsidence of swelling. Therapeutic results have been excellent. In recent years

Inverse gas chromatography determination of some physicochemical parameters of a high rank Colombian coal

Energy Technology Data Exchange (ETDEWEB)

Baquero-Haeberlin, M.C.; Rincon, J.M. [Universidad Nacional de Colombia, Santafe de Bogota (Colombia). Departamento de Quimica

1997-12-31

Dispersive component of the free surface energy of a Colombian semianthracite type coal - Paramo de Guerrero - was determined by Inverse Gas Chromatography (IGC), at zero coverage injecting the series of n-alkanes at 313, 333, 353 and 373 K. For the retention time, the mass center determination was used instead of the maximum peak in the chromatograms. The free surface energy (-{Delta}G{sub A}) increase linearly with the carbon atom number to the alkanes but is not constant due, probably to the conformational structure of the probes. The IGC study of the adsorption process in function of the temperature, provides the respective Enthalpy and Entropy values. (orig.)

Dependence of the constitution, microstructure and electrochemical behaviour of magnetron sputtered Li-Ni-Mn-Co-O thin film cathodes for lithium-ion batteries on the working gas pressure and annealing conditions

Energy Technology Data Exchange (ETDEWEB)

Strafela, Marc; Fischer, Julian; Leiste, Harald; Rinke, Monika; Bergfeldt, Thomas; Seifert, Hans Juergen; Ulrich, Sven [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Applied Materials (IAM); Music, Denis; Chang, Keke; Schneider, Jochen [RWTH Aachen Univ. (Germany). Materials Chemistry

2017-11-15

Li(Ni{sub 1/3}Mn{sub 1/3}Co{sub 1/3})O{sub 2} as a cathode material for lithium ion batteries shows good thermal stability, high reversible capacity (290 mAh g{sup -1}), good rate capability and better results in terms of environmental friendliness. In this paper thin film cathodes in the material system Li-Ni-Mn-Co-O were deposited onto silicon and stainless steel substrates, by non-reactive r.f. magnetron sputtering from a ceramic Li{sub 1.18}(Ni{sub 0.39}Mn{sub 0.19}Co{sub 0.35})O{sub 1.97} target at various argon working gas pressures between 0.2 Pa and 20 Pa. A comprehensive study on the composition and microstructure was carried out. The results showed that the elemental composition varies depending on argon working gas pressure. The elemental composition was determined by inductively coupled plasma optical emission spectroscopy in combination with carrier gas hot extraction. The films showed different grain orientations depending argon working gas pressures. The degree of cation order in the lattice structure of the films deposited at 0.5 Pa and 7 Pa argon working gas pressure, was increased by annealing in an argon/oxygen atmosphere at different pressures for one hour. The microstructure of the films varies with annealing gas pressure and is characterized using X-ray diffraction and unpolarized micro-Raman spectroscopy at room temperature. Electrochemical characterization of as-deposited and annealed films was carried out by galvanostatic cycling in Li-Ni-Mn-Co-O half-cells against metallic lithium. Correlations between process parameters, constitution, microstructure and electrochemical behaviour are discussed in detail.

Improved Magnetron Stability and Reduced Noise in Efficient Transmitters for Superconducting Accelerators

Energy Technology Data Exchange (ETDEWEB)

Kazakevich, G. [MUONS Inc., Batavia; Johnson, R. [MUONS Inc., Batavia; Lebedev, V. [Fermilab; Yakovlev, V. [Fermilab

2018-04-01

State of the art high-current superconducting accelerators require efficient RF sources with a fast dynamic phase and power control. This allows for compensation of the phase and amplitude deviations of the accelerating voltage in the Superconducting RF (SRF) cavities caused by microphonics, etc. Efficient magnetron transmitters with fast phase and power control are attractive RF sources for this application. They are more cost effective than traditional RF sources such as klystrons, IOTs and solid-state amplifiers used with large scale accelerator projects. However, unlike traditional RF sources, controlled magnetrons operate as forced oscillators. Study of the impact of the controlling signal on magnetron stability, noise and efficiency is therefore important. This paper discusses experiments with 2.45 GHz, 1 kW tubes and verifies our analytical model which is based on the charge drift approximation.

Accounting for the Complex Surface Structure in Ellipsometric Studies of the Effects of Magnetron Sputtering Modes on the Growth and Optical Properties of In2O3 Films

Science.gov (United States)

Tikhii, A. A.; Nikolaenko, Yu. M.; Gritskih, V. A.; Svyrydova, K. A.; Murga, V. V.; Zhikhareva, Yu. I.; Zhikharev, I. V.

2018-03-01

The efficiency of invoking additional information on optical transmission in solving the inverse problem of ellipsometry by a minimization method is demonstrated in practice for In2O3 fi doped and nondoped with Sn on Al2O3 (012) substrates. This approach allows the thickness and refractive index of thin films with rough surfaces to be uniquely determined. Solutions of the inverse problem in the framework of one-, two-, and multilayer models are compared. The last provides the best description of the experimental data and the correct parameters of the samples. The dependences of the investigated properties of films produced with different magnetron sputtering modes are found using the above methods and models and do not contradict general concepts about the film formation by this material.

Dielectric properties of DC reactive magnetron sputtered Al{sub 2}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Prasanna, S. [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore, 641 004 (India); Mohan Rao, G. [Department of Instrumentation, Indian Institute of Science (IISc), Bangalore, 560 012 (India); Jayakumar, S., E-mail: s_jayakumar_99@yahoo.com [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore, 641 004 (India); Kannan, M.D. [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore, 641 004 (India); Ganesan, V. [Low Temperature Lab, UGC-DAE Consortium for Scientific Research (CSR), Indore, 452 017 (India)

2012-01-31

Alumina (Al{sub 2}O{sub 3}) thin films were sputter deposited over well-cleaned glass and Si < 100 > substrates by DC reactive magnetron sputtering under various oxygen gas pressures and sputtering powers. The composition of the films was analyzed by X-ray photoelectron spectroscopy and an optimal O/Al atomic ratio of 1.59 was obtained at a reactive gas pressure of 0.03 Pa and sputtering power of 70 W. X-ray diffraction results revealed that the films were amorphous until 550 Degree-Sign C. The surface morphology of the films was studied using scanning electron microscopy and the as-deposited films were found to be smooth. The topography of the as-deposited and annealed films was analyzed by atomic force microscopy and a progressive increase in the rms roughness of the films from 3.2 nm to 4.53 nm was also observed with increase in the annealing temperature. Al-Al{sub 2}O{sub 3}-Al thin film capacitors were then fabricated on glass substrates to study the effect of temperature and frequency on the dielectric property of the films. Temperature coefficient of capacitance, AC conductivity and activation energy were determined and the results are discussed. - Highlights: Black-Right-Pointing-Pointer Al{sub 2}O{sub 3} thin films were deposited by DC reactive magnetron sputtering. Black-Right-Pointing-Pointer The films were found to be amorphous up to annealing temperature of 550 C. Black-Right-Pointing-Pointer An increase in rms roughness of the films was observed with annealing. Black-Right-Pointing-Pointer Al-Al{sub 2}O{sub 3}-Al thin film capacitors were fabricated and dielectric constant was 7.5. Black-Right-Pointing-Pointer The activation energy decreased with increase in frequency.

Effects of Al concentrations on the microstructure and mechanical properties of Ti–Al–N films deposited by RF-ICPIS enhanced magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Li, Dongke [The School of Physics and Telecommunication Engineering, SCNU, Guangzhou 510000 (China); Chen, JunFang, E-mail: chenjf@scnu.edu.com [The School of Physics and Telecommunication Engineering, SCNU, Guangzhou 510000 (China); Research Resources Center, SCNU, Guangzhou 510000 (China); Zou, Changwei, E-mail: qingyihaiyanas@163.com [Department of Physics and Development Center for New Materials Engineering and Technology in University of Guangdong, Zhanjiang Normal University, Zhanjiang 524048 (China); Ma, Junhui; Li, Pengfei; Li, Ye [The School of Physics and Telecommunication Engineering, SCNU, Guangzhou 510000 (China)

2014-10-01

Highlights: • RF-ICPIS enhanced magnetron sputtering technique is used for Ti–Al–N deposition. • Al contents has closed relation with total gas pressure. • Ti–Al–N films with high Al contents of 34.16 at.% are obtained. • Effects of Al on the microstructure and mechanical properties are discussed. - Abstract: Ti–Al–N films were deposited on Si (1 0 0) and mirror-polished stainless steel at 300 °C by RF-ICPIS enhanced magnetron sputtering technique. Focusing on the effects of Al concentrations on the microstructure and mechanical properties of Ti–Al–N films, the structure and the growth morphology were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). Ti–Al–N films with highest Al contents of were deposited at total gas pressure of 1.0 Pa. XRD experiments exhibited that the Ti–Al–N films were f.c.c structure with diffraction peaks at 2θ = 37.1°, 43.5°, 63.2°, and 75.1°, respectively. The FWHM values of (1 1 1) diffraction peaks showed a decrease while the (2 2 0) diffraction peaks showed an increase trend with the increasing of Al concentrations. With the variation of total gas pressure from 0.5 to 1.5 Pa, the RMS values of Ti–Al–N films increased from 1.286 to 7.751 nm. The hardness of the Ti–Al–N films was in the range of 28.4–36.2 GPa while the friction coefficients were in the range of 0.339–0.732.

Origin of stress in radio frequency magnetron sputtered zinc oxide thin films

Science.gov (United States)

Menon, Rashmi; Gupta, Vinay; Tan, H. H.; Sreenivas, K.; Jagadish, C.

2011-03-01

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10-50 mTorr) and oxygen percentage (50-100%) in the reactive gas (Ar + O2) mixture. The as-grown films were found to be stressed over a wide range from -1 × 1011 to -2 × 108 dyne/cm2 that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.

Solid-state pulse modulator for a 1.7-MW X-band magnetron

International Nuclear Information System (INIS)

Choi, Jaegu; Shin, Yongmoon; Choi, Youngwook; Kim, Kwanho

2014-01-01

Medical linear accelerators (LINAC) for cancer treatment require pulse modulators to generate high-power pulses with a fast rise time, flat top and short duration to drive high-power magnetrons. Solid-state pulse modulators (SSPM) for medical LINACs that use high power semiconductor switches with high repetition rates, high stability and long lifetimes have been introduced to replace conventional linear-type pulse generators that use gaseous discharge switches. In this paper, the performance of a developed SSPM, which mainly consists of a capacitor charger, an insulated-gate bipolar transistor (IGBT) - capacitor stack and a pulse transformer, is evaluated with a dummy load and an X-band magnetron load. A theoretical analysis of the pulse transformer, which is a critical element of the SSPM, is carried out. The output pulse has a fast rise time and low droop, such that the modulator can drive the X-band magnetron.

Particle-balance models for pulsed sputtering magnetrons

Science.gov (United States)

Huo, Chunqing; Lundin, D.; Gudmundsson, J. T.; Raadu, M. A.; Bradley, J. W.; Brenning, N.

2017-09-01

The time-dependent plasma discharge ionization region model (IRM) has been under continuous development during the past decade and used in several studies of the ionization region of high-power impulse magnetron sputtering (HiPIMS) discharges. In the present work, a complete description of the most recent version of the IRM is given, which includes improvements, such as allowing for returning of the working gas atoms from the target, a separate treatment of hot secondary electrons, addition of doubly charged metal ions, etc. To show the general applicability of the IRM, two different HiPIMS discharges are investigated. The first set concerns 400 μs long discharge pulses applied to an Al target in an Ar atmosphere at 1.8 Pa. The second set focuses on 100 μs long discharge pulses applied to a Ti target in an Ar atmosphere at 0.54 Pa, and explores the effects of varying the magnetic field strength. The model results show that Al2+ -ions contribute negligibly to the production of secondary electrons, while Ti2+ -ions effectively contribute to the production of secondary electrons. Similarly, the model results show that for an argon discharge with Al target the contribution of Al+-ions to the discharge current at the target surface is over 90% at 800 V. However, at 400 V the Al+-ions and Ar+-ions contribute roughly equally to the discharge current in the initial peak, while in the plateau region Ar+-ions contribute to roughly \\frac{2}{3} of the current. For high currents the discharge with Al target develops almost pure self-sputter recycling, while the discharge with Ti target exhibits close to a 50/50 combination of self-sputter recycling and working gas-recycling. For a Ti target, a self-sputter yield significantly below unity makes working gas-recycling necessary at high currents. For the discharge with Ti target, a decrease in the B-field strength, resulted in a corresponding stepwise increase in the discharge resistivity.

A Two-Dimensional Post-Stack Seismic Inversion for Acoustic Impedance of Gas and Hydrate Bearing Deep-Water Sediments Within the Continental Slope of the Ulleung Basin, East Sea, Korea

Directory of Open Access Journals (Sweden)

Keumsuk Lee

2013-01-01

Full Text Available A post-stack inversion of 2D seismic data was conducted to estimate the spatial distribution of acoustic impedance associated with gas and hydrates in the Ulleung Basin, East Sea, Korea constrained by logs from three boreholes drilled on its continental margin. A model-based inversion was applied to a Plio-Quaternary succession composed of alternations of unconsolidated mass-flow deposits/turbidites. A comparison of seismic reflections and synthetic data computed from impedance logs is shown for two zones. An upper (steep slope zone contains a moderately continuous, possibly bottom-simulating reflector feature along the corresponding section. This feature may be associated with a lithology boundary near a drill site in addition to, or instead of, a stability boundary of gas hydrates (i.e., gas below and hydrates above. The lower (gentle slope zone has locally cross-cutting reflection patterns that are more likely to be attributed to gas- and hydrate-related physical phenomena than to spatiotemporal changes in lithology. This seismic inversion is informative and useful, making a contribution to enhance the interpretability of the seismic profiles for a potential hydrate recovery.

Photoelectron-spectroscopic and reactivity investigation of thin Pd-Sn films prepared by magnetron sputtering

International Nuclear Information System (INIS)

Skala, T.; Veltruska, K.; Sedlacek, L.; Masek, K.; Matolinova, I.; Matolin, V.

2007-01-01

We have studied Pd-Sn layers with different composition prepared by magnetron sputtering. Layers were sputtered onto Al 2 O 3 and SiO 2 substrates and studied by X-ray photoelectron spectroscopy (XPS). Spectra confirmed that after vacuum annealing residual oxygen and carbon have been removed and bimetallic bonds have been created. The shift of Pd 3d 5/2 core level to higher binding energy followed by the peak narrowing in dependence on the composition was observed, accompanied by the shift of the Pd 4d in the valence band region, induced by hybridization of Pd-d and Sn-s,p states. Experiments carried out on a gas-flow reactor indicate increasing temperature of the CO oxidation with tin ratio in the alloy

Defect free C-axis oriented zinc oxide (ZnO) films grown at room temperature using RF magnetron sputtering

International Nuclear Information System (INIS)

Kunj, Saurabh; Sreenivas, K.

2016-01-01

Radio frequency Magnetron sputtering technique was employed to fabricate ZnO thin films on quartz substrate at room temperature. The effect of varying oxygen to argon (O_2/Ar) gas ratio on the structural and photoluminescence properties of the film is analyzed.X-ray diffraction (XRD) spectra reveals the formation of hexagonal wurtzite structured ZnO thin films with preferred orientation along (002) plane. Photoluminescence (PL) characterization reveals the preparation of highly crystalline films exhibiting intense Ultraviolet (UV) emission with negligible amount of defects as indicated by the absence of Deep Level Emission (DLE) in the PL spectra.

Defect free C-axis oriented zinc oxide (ZnO) films grown at room temperature using RF magnetron sputtering

Science.gov (United States)

Kunj, Saurabh; Sreenivas, K.

2016-05-01

Radio frequency Magnetron sputtering technique was employed to fabricate ZnO thin films on quartz substrate at room temperature. The effect of varying oxygen to argon (O2/Ar) gas ratio on the structural and photoluminescence properties of the film is analyzed.X-ray diffraction (XRD) spectra reveals the formation of hexagonal wurtzite structured ZnO thin films with preferred orientation along (002) plane. Photoluminescence (PL) characterization reveals the preparation of highly crystalline films exhibiting intense Ultraviolet (UV) emission with negligible amount of defects as indicated by the absence of Deep Level Emission (DLE) in the PL spectra.

Defect free C-axis oriented zinc oxide (ZnO) films grown at room temperature using RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Kunj, Saurabh, E-mail: saurabhkunj22@gmail.com; Sreenivas, K. [Department of Physics & Astrophysics, University of Delhi, Delhi-110007 (India)

2016-05-23

Radio frequency Magnetron sputtering technique was employed to fabricate ZnO thin films on quartz substrate at room temperature. The effect of varying oxygen to argon (O{sub 2}/Ar) gas ratio on the structural and photoluminescence properties of the film is analyzed.X-ray diffraction (XRD) spectra reveals the formation of hexagonal wurtzite structured ZnO thin films with preferred orientation along (002) plane. Photoluminescence (PL) characterization reveals the preparation of highly crystalline films exhibiting intense Ultraviolet (UV) emission with negligible amount of defects as indicated by the absence of Deep Level Emission (DLE) in the PL spectra.

Characterization of ZnO:SnO{sub 2} (50:50) thin film deposited by RF magnetron sputtering technique

Energy Technology Data Exchange (ETDEWEB)

Cynthia, S. R.; Sanjeeviraja, C.; Ponmudi, S. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi-630004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi-630004 (India)

2016-05-06

Zinc oxide (ZnO) and tin oxide (SnO{sub 2}) thin films have attracted significant interest recently for use in optoelectronic application such as solar cells, flat panel displays, photonic devices, laser diodes and gas sensors because of their desirable electrical and optical properties and wide band gap. In the present study, thin films of ZnO:SnO{sub 2} (50:50) were deposited on pre-cleaned microscopic glass substrate by RF magnetron sputtering technique. The substrate temperature and RF power induced changes in structural, surface morphological, compositional and optical properties of the films have been studied.

Structure evolution of zinc oxide thin films deposited by unbalance DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Aryanto, Didik, E-mail: didi027@lipi.go.id [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); Materials Research Group, Physics Department, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Marwoto, Putut; Sugianto [Physics Department, Faculty of Mathematics and Science, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Materials Research Group, Physics Department, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia); Sudiro, Toto [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); Birowosuto, Muhammad D. [Research Center for Physics, Indonesian Institute of Sciences, Serpong 15314, Tangerang Selatan (Indonesia); CINTRA UMI CNRS/NTU/THALES 3288 Research Techno Plaza, 50 Nanyang Drive, Border X Block, level 6, 637553 (Singapore); Sulhadi [Physics Department, Faculty of Mathematics and Science, Universitas Negeri Semarang, Gunungpati, Semarang 50229 Jawa Tengah (Indonesia)

2016-04-19

Zinc oxide (ZnO) thin films are deposited on corning glass substrates using unbalanced DC magnetron sputtering. The effect of growth temperature on surface morphology and crystallographic orientation of ZnO thin film is studied using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The surface morphology and crystallographic orientation of ZnO thin film are transformed against the increasing of growth temperature. The mean grain size of film and the surface roughness are inversely and directly proportional towards the growth temperature from room temperature to 300 °C, respectively. The smaller grain size and finer roughness of ZnO thin film are obtained at growth temperature of 400 °C. The result of AFM analysis is in good agreement with the result of XRD analysis. ZnO thin films deposited in a series of growth temperatures have hexagonal wurtzite polycrystalline structures and they exhibit transformations in the crystallographic orientation. The results in this study reveal that the growth temperature strongly influences the surface morphology and crystallographic orientation of ZnO thin film.

Simulation Study Using an Injection Phase-locked Magnetron as an Alternative Source for SRF Accelerators

Energy Technology Data Exchange (ETDEWEB)

Wang, Haipeng [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Plawski, Tomasz E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2015-09-01

As a drop-in replacement for the CEBAF CW klystron system, a 1497 MHz, CW-type high-efficiency magnetron using injection phase lock and amplitude variation is attractive. Amplitude control using magnetic field trimming and anode voltage modulation has been studied using analytical models and MATLAB/Simulink simulations. Since the 1497 MHz magnetron has not been built yet, previously measured characteristics of a 2.45GHz cooker magnetron are used as reference. The results of linear responses to the amplitude and phase control of a superconducting RF (SRF) cavity, and the expected overall benefit for the current CEBAF and future MEIC RF systems are presented in this paper.

ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

Energy Technology Data Exchange (ETDEWEB)

Purandare, Yashodhan, E-mail: Y.Purandare@shu.ac.uk; Ehiasarian, Arutiun; Hovsepian, Papken [Nanotechnology Centre for PVD Research, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Santana, Antonio [Ionbond AG Olten, Industriestrasse 211, CH-4600 Olten (Switzerland)

2014-05-15

Zirconium nitride (ZrN) coatings were deposited on 1 μm finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5 μm with hardness in the range of 30–40 GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

Computer analysis, design and construction of the BNL Mk V magnetron

International Nuclear Information System (INIS)

McKenzie-Wilson, R.B.; Kovarik, V.J.

1981-01-01

As part of a program to develop a high energy neutral beam injector for fusion reactor applications, the BNL Neutral Beam Group is studying, among other options, a surface plasma source of the magnetron type. This source has been developed to the point at which a large compact model, known as the Mk V magnetron, has been designed and constructed. The source is designed to operate in the steady state mode and to produce 1-2A of H - (D - ) ions at 25 kV. Under these conditions, 18 KW of heat are removed from the source by the cooling system

Pressure dependence of Ar.sup.+./sup..sub.2./sub., ArTi.sup.+./sup., and Ti.sup.+./sup..sub.2./sub. dimer formation in a magnetron sputtering discharge

Czech Academy of Sciences Publication Activity Database

Hippler, R.; Čada, Martin; Straňák, V.; Hubička, Zdeněk; Helm, C.A.

2017-01-01

Roč. 50, č. 44 (2017), s. 1-8, č. článku 445205. ISSN 0022-3727 R&D Projects: GA ČR GA17-08389S Institutional support: RVO:68378271 Keywords : magnetron sputtering * ion mass spectrometry * dimer formation * cluster formation Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016

Magnetic field effects on coating deposition rate and surface morphology coatings using magnetron sputtering

International Nuclear Information System (INIS)

Yang, Yu-Sen; Huang, Wesley

2010-01-01

Chromium nitride coatings exhibit superior hardness, excellent wear and oxidation resistance, and are widely applied in the die and mold industries. The aim of this study was to investigate magnetic field effects on the deposition rate and surface morphology of chromium nitride coatings deposited by magnetron sputtering. Four types of magnetic field configurations, including the magnetron sputtering system, SNSN, SNNN, and intermediate magnetron modification, are discussed in this paper. SKD11 cold work die steel and a silicon (100) chip were used as substrates in the chromium nitride depositions. The process parameters, such as target current, substrate bias, and the distance between the substrate and target, are at fixed conditions, except for the magnetic arrangement type. The experimental results showed that the deposition rates of the four types of magnetic field configurations were 1.06, 1.38, 1.67 and 1.26 µm h −1 , respectively. In these cases, the SNNN type performs more than 58% faster than the unbalanced magnetron configuration does for the deposition rate. The surface morphology of chromium nitride films was also examined by SEM and is discussed in this paper

Influence of Microwave Power on the Properties of Hydrogenated Diamond-Like Carbon Films Prepared by ECR Plasma Enhanced DC Magnetron Sputtering

International Nuclear Information System (INIS)

Ru Lili; Huang Jianjun; Gao Liang; Qi Bing

2010-01-01

Electron cyclotron resonance (ECR) plasma was applied to enhance the direct current magnetron sputtering to prepare hydrogenated diamond-like carbon (H-DLC) films. For different microwave powers, both argon and hydrogen gas are introduced separately as the ECR working gas to investigate the influence of microwave power on the microstructure and electrical property of the H-DLC films deposited on P-type silicon substrates. A series of characterization methods including the Raman spectrum and atomic force microscopy are used. Results show that, within a certain range, the increase in microwave power affects the properties of the thin films, namely the sp 3 ratio, the hardness, the nanoparticle size and the resistivity all increase while the roughness decreases with the increase in microwave power. The maximum of resistivity amounts to 1.1 x 10 9 Ω · cm. At the same time it is found that the influence of microwave power on the properties of H-DLC films is more pronounced when argon gas is applied as the ECR working gas, compared to hydrogen gas.

RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

Science.gov (United States)

Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

2014-10-01

Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Yuan, Xiaohong, E-mail: yxhong1981_2004@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Xu, Wenzheng, E-mail: xwz8199@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Huang, Fenglin, E-mail: windhuang325@163.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Chen, Dongsheng, E-mail: mjuchen@126.com [Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China)

2016-12-30

Highlights: • Ag/ZnO composite film was successfully deposited on polyester fabric by magnetron sputtering technique. • Ag film was easily oxidized into Ag{sub 2}O film in high vacuum oxygen environment. • The zinc film coated on the surface of Ag film before RF reactive sputtering could protect the silver film from oxidation. • Polyester fabric coated with Ag/ZnO composite film can obtained structural color. • The anti-ultraviolet and antistatic properties of polyester fabric coated with Ag/ZnO composite film all were good. - Abstract: Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag{sub 2}O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

Characterization of single crystal uranium-oxide thin films grown via reactive-gas magnetron sputtering on yttria-stabilized zirconia and sapphire

Energy Technology Data Exchange (ETDEWEB)

Strehle, Melissa M.; Heuser, Brent J., E-mail: bheuser@illinois.edu; Elbakhshwan, Mohamed S.; Han Xiaochun; Gennardo, David J.; Pappas, Harrison K.; Ju, Hyunsu

2012-06-30

The microstructure and valence states of three single crystal thin film systems, UO{sub 2} on (11{sup Macron }02) r-plane sapphire, UO{sub 2} on (001) yttria-stabilized zirconia, and U{sub 3}O{sub 8} on (11{sup Macron }02) r-plane sapphire, grown via reactive-gas magnetron sputtering are analyzed primarily with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). XRD analysis indicates the growth of single crystal domains with varying degrees of mosaicity. XPS and UPS analyses yield U-4f, U-5f, O-1s, and O-2p electron binding energies consistent with reported bulk values. A change from p-type to n-type semiconductor behavior induced by preferential sputtering of oxygen during depth profile analysis was observed with both XPS and UPS. Trivalent cation impurities (Nd and Al) in UO{sub 2} lower the Fermi level, shifting the XPS spectral weight. This observation is consistent with hole-doping of a Mott-Hubbard insulator. The uranium oxide-(11{sup Macron }02) sapphire system is unstable with respect to Al interdiffusion across the film-substrate interface at elevated temperature. - Highlights: Black-Right-Pointing-Pointer Single crystal uranium-oxides grown on sapphire and yttria-stabilized zirconia. Black-Right-Pointing-Pointer Anion and cation valence states studied by photoelectron emission spectroscopy. Black-Right-Pointing-Pointer Trivalent Nd and Al impurities lower the Fermi level. Black-Right-Pointing-Pointer Uranium-oxide films on sapphire found to be unstable with respect to Al interdiffusion.

SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

Science.gov (United States)

Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

2011-02-01

As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

Effect of N Concentration on Microstructure Evolution of the Nanostructured (Al, Ti, SiN Coatings Prepared by d.c. Reactive Magnetron Sputtering

Directory of Open Access Journals (Sweden)

L. Jakab-Farkas

2009-12-01

Full Text Available Nanostructured (Al, Ti, SiN thin film coatings were synthesized by d.c. reactive magnetron sputtering, performed in an Ar/N2 gas mixture from a planar rectangular Al:Ti:Si=50:25:25 alloyed target. The mass flow of N2 reactive gas was strictly controlled in sputtering process. Conventional transmission electron microscopy (TEM technique was used for microstructure investigation of the as deposited films. Cross-sectional cuts performed through the deposited films revealed distinct microstructure evolution for different samples. It was found that the variation of the reactive gas amount induced changes in film microstructure. The metallic AlTiSi film exhibited strong columnar growth with a crystalline structure. The addition of a small amount of nitrogen to the process gas leads to a crystallite refinement. Further increase of N concentration resulted in evolution of fine lamellae growth morphology consisting of hainlike pearls in a dendrite, clusters of very fine grains in close crystallographic orientation.

Time resolved 2-D optical imaging of a pulsed unbalanced magnetron plasma

International Nuclear Information System (INIS)

Bradley, J W; Clarke, G C B; Braithwaite, N St J; Bryant, P M; Kelly, P J

2006-01-01

Using wavelength filtered two dimensional (2-D) optical imaging, the temporal and spatial evolution of selected excited species in a pulsed magnetron discharge has been studied. A titanium target was sputtered at a pulse frequency of 100 kHz, in an argon atmosphere, at an operating pressure of 0.27 Pa. The radial information of the emissivity was determined using the Abel inversion technique. The results show strong excitation of the observed species above the racetrack in the on-time, and the possible development of an ion-acoustic wave, initiated after the off-on transition. The on-off transition is accompanied by a burst of light from the plasma bulk consistent with the transient plasma potential reaching about +200 V. During this phase, we argue that there is a release of secondary electrons from the grounded substrate and walls due to ion bombardment, as well as an increased confinement of energetic plasma electrons. The characteristic decay times of the selected transitions at 750.4, 751.5, 810.4 and 811.5 nm (ArI), present within the bandpass width of our filters, is briefly discussed in terms of the production of fast electrons in the system

Characterization of AZO and Ag based films prepared by RF magnetron sputtering

International Nuclear Information System (INIS)

Miao, Dagang; Jiang, Shouxiang; Zhao, Hongmei; Shang, Songmin; Chen, Zhuoming

2014-01-01

Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films

Operational experience with the BNL magnetron H- source

International Nuclear Information System (INIS)

Witkover, R.L.

1983-01-01

A magnetron H - source with a grooved cathode has been in operation at the BNL Linac for over 18 months. The source has run at 5 pps with a 600 μsec pulse width for periods as long as 5 months. Its development and performance will be discussed

Synthesis and morphology of iron-iron oxide core-shell nanoparticles produced by high pressure gas condensation

NARCIS (Netherlands)

Xing, Lijuan; ten Brink, Gert H.; Chen, Bin; Schmidt, Franz P.; Haberfehlner, Georg; Hofer, Ferdinand; Kooi, Bart J.; Palasantzas, Georgios

2016-01-01

Core-shell structured Fe nanoparticles (NPs) produced by high pressure magnetron sputtering gas condensation were studied using transmission electron microscopy (TEM) techniques, electron diffraction, electron energy-loss spectroscopy (EELS), tomographic reconstruction, and Wulff shape construction

Effect of nitrogen doping on TiO.sub.x./sub.N.sub.y./sub. thin film formation at reactive high-power pulsed magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Straňák, Vítězslav; Quaas, M.; Bogdanowicz, R.; Steffen, H.; Wulff, H.; Hubička, Zdeněk; Tichý, M.; Hippler, R.

2010-01-01

Roč. 43, č. 28 (2010), s. 1-7 ISSN 0022-3727 R&D Projects: GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002 Grant - others:AVČR(CZ) M100100915 Institutional research plan: CEZ:AV0Z10100522 Keywords : magnetron sputtering * TiO 2 * pulse discharge * XRD * band gap Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.105, year: 2010 http://iopscience.iop.org/0022-3727/43/28/285203/

Origin of stress in radio frequency magnetron sputtered zinc oxide thin films

International Nuclear Information System (INIS)

Menon, Rashmi; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

2011-01-01

Highly c-axis oriented ZnO thin films have been deposited on silicon substrates by planar rf magnetron sputtering under varying pressure (10-50 mTorr) and oxygen percentage (50-100%) in the reactive gas (Ar + O 2 ) mixture. The as-grown films were found to be stressed over a wide range from -1 x 10 11 to -2 x 10 8 dyne/cm 2 that in turn depends strongly on the processing conditions, and the film becomes stress free at a unique combination of sputtering pressure and reactive gas composition. Raman spectroscopy and photoluminescence (PL) analyses identified the origin of stress as lattice distortion due to defects introduced in the ZnO thin film. FTIR study reveals that Zn-O bond becomes stronger with the increase in oxygen fraction in the reactive gas mixture. The lattice distortion or stress depends on the type of defects introduced during deposition. PL spectra show the formation of a shoulder in band emission with an increase in the processing pressure and are related to the presence of stress. The ratio of band emission to defect emission decreases with the increase in oxygen percentage from 50 to 100%. The studies show a correlation of stress with the structural, vibrational, and photoluminescence properties of the ZnO thin film. The systematic study of the stress will help in the fabrication of efficient devices based on ZnO film.

Multi-sided metallization of textile fibres by using magnetron system with grounded cathode

Directory of Open Access Journals (Sweden)

Chodun Rafał

2017-10-01

Full Text Available The synthesis of coatings on textiles fibers enables functionalization of their properties e.g.: changing the reaction on IR radiation. In our experiment, a magnetron with a grounded cathode and positively biased anode was used as a source of plasma. A ring anode was positioned at 8 cm distance from the cathode. Samples of glass and cotton textile were placed at the plane of the anode. Ti and TiN coatings were deposited by sputtering of titanium target in Ar or Ar+ N2 atmosphere. SEM studies showed that, using the magnetron system described above, the textile fibers were covered by the 2 μm to 3 μm thick coatings. Unexpectedly, the coatings were deposited at both sides of the samples: the front side was exposed to glow discharge plasma and the backside was completely shaded from the plasma. IR optical investigation exhibited significant change in reflectance and transmittance of the coated textiles. The using of standard magnetron system (grounded anode and cathode at negative potential resulted in a coating deposition at the textile side exposed to the plasma action only. We believe that the multi-sided deposition of coatings observed during the process run with magnetron with grounded cathode is a result of an ambipolar diffusion mechanism in the anodic potential drop region.

Superhydrophobic photocatalytic PTFE – Titania coatings deposited by reactive pDC magnetron sputtering from a blended powder target

Energy Technology Data Exchange (ETDEWEB)

Ratova, Marina, E-mail: marina_ratova@hotmail.com; Kelly, Peter J.; West, Glen T.

2017-04-01

The production of photocatalytic coatings with superhydrophobic properties, as opposed to the conventional hydrophilic properties, is desirable for the prevention of adhesion of contaminants to photocatalytic surfaces with subsequent deterioration of photocatalytic properties. In this work polytetrafluoroethylene (PTFE) – TiO{sub 2} composite thin films were deposited using a novel method of reactive pulsed direct current (pDC) magnetron sputtering of a blended PTFE – titanium oxide powder target. The surface characteristics and photocatalytic properties of the deposited composite coatings were studied. The as-deposited coatings were annealed at 523 K in air and analysed with Raman spectroscopy, optical profilometry and scanning electron microscopy. Hydrophobicity was assessed though measurements of water contact angles, and photocatalytic properties were studied via methylene blue dye degradation under UV irradiation. It was found that variations of gas flow and, hence, process pressures allowed deposition of samples combining superhydrophobicity with stable photocatalytic efficiency under UV light irradiation. Reversible wettability behaviour was observed with the alternation of light-dark cycles. - Highlights: • PTFE-TiO{sub 2} coatings were deposited by pDC reactive magnetron sputtering. • Blended powder target was used for coatings deposition. • Deposited coatings combined superhydrophobic and photocatalytic properties. • Under UV irradiation coatings exhibited reversible wettability.

The effect of sputtering gas pressure on the structure and optical properties of MgNiO films grown by radio frequency magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Xie, Wuze; Jiao, Shujie, E-mail: shujiejiao@gmail.com; Wang, Dongbo; Gao, Shiyong; Wang, Jinzhong; Yu, Qingjiang; Li, Hongtao

2017-05-31

Highlights: • MgNiO thin films were fabricated by radio frequency magnetron sputtering. • The structure and optical properties of MgNiO films were studied. • The mechanism of phase separation was discussed in detail. • The effect of different sputtering pressure also was discussed. - Abstract: In this study, MgNiO thin films were grown on quartz substrates by radio frequency (RF) magnetron sputtering. The influence of different sputtering pressures on the crystalline and optical properties of MgNiO thin films has been studied. X-ray diffraction measurement indicates that the MgNiO films are cubic structure with (200) preferred orientation. UV–vis transmission spectra show that all the MgNiO thin films show more than 75% transmission at visible region, and the absorption edges of all thin films locate at solar-blind region (220 nm–280 nm). The lattice constant and Mg content of MgNiO samples were calculated using X-ray diffraction and transmission spectra data. The phase separation is observed both in the X-ray diffraction patterns and transmission spectra, and the phase separation is studied in detail based on the crystal growth theory and sputtering process.

High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

2015-01-01

Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films.

High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

International Nuclear Information System (INIS)

Lisco, F.; Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

2015-01-01

Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films

Discharge Characteristic of VHF-DC Superimposed Magnetron Sputtering System

Science.gov (United States)

Toyoda, Hirotaka; Fukuoka, Yushi; Fukui, Takashi; Takada, Noriharu; Sasai, Kensuke

2014-10-01

Magnetron plasmas are one of the most important tools for sputter deposition of thin films. However, energetic particles from the sputtered target such as backscattered rare gas atoms or oxygen negative ions from oxide targets sometimes induce physical and chemical damages as well as surface roughening to the deposited film surface during the sputtering processes. To suppress kinetic energy of such particles, superposition of RF or VHF power to the DC power has been investigated. In this study, influence of the VHF power superposition on the DC target voltage, which is important factor to determine kinetic energy of high energy particles, is investigated. In the study, 40 MHz VHF power was superimposed to an ITO target and decrease in the target DC voltage was measured as well as deposited film deposition properties such as deposition rate or electrical conductivity. From systematic measurement of the target voltage, it was revealed that the target voltage can be determined by a very simple parameter, i.e., a ratio of VHF power to the total input power (DC and VHF powers) in spite of the DC discharge current. Part of this work was supported by ASTEP, JST.

Stratigraphic inversion of pre-stack multicomponent data; Inversion stratigraphique multicomposante avant sommation

Energy Technology Data Exchange (ETDEWEB)

Agullo, Y.

2005-09-15

This thesis present the extension of mono-component seismic pre-stack data stratigraphical inversion method to multicomponent data, with the objective of improving the determination of reservoir elastic parameters. In addiction to the PP pressure waves, the PS converted waves proved their interest for imaging under gas clouds; and their potential is highly significant for the characterization of lithologies, fluids, fractures... Nevertheless the simultaneous use ol PP and PS data remains problematic because of their different the time scales. To jointly use the information contained in PP and PS data, we propose a method in three steps first, mono-component stratigraphic inversions of PP then PS data; second, estimation of the PP to PS time conversion law; third, multicomponent stratigraphic inversion. For the second point, the estimation of the PP to PS conversion law is based on minimizing the difference between the S impedances obtained from PP and PS mono-component stratigraphic inversion. The pre-stack mono-component stratigraphic inversions was adapted to the case of multicomponent data by leaving each type of data in its own time scale in order to avoid the distortion of the seismic wavelet. The results obtained on a realistic synthetic PP-PS case show on one hand that determining PP to PS conversion law (from the mono-component inversion results) is feasible, and on the other hand that the joint inversion of PP and PS data with this conversion law improves the results compared to the mono-component inversion ones. Although this is presented within the framework of the PP and PS multi-component data, the developed methodology adapts directly to PP and SS data for example. (author)

Stationary Population Inversion in an Expanding Argon Plasma Jet by Helium Puffing

International Nuclear Information System (INIS)

Akatsuka, H.; Kano, K.

2005-01-01

An experiment of He gas-contact for generating population inversion in a recombining Ar plasma jet is carried out. Population inversion between Ar I excited states 5s' → 4p'[1/2]1 and 5s' → 4p[3/2]1,2, [5/2]2,3 is created by helium gas-contact cooling of electrons, whereas it is not created without gas-contact. Ar I lines 1.14 μm, 1.34 μm, and 1.09 μm are strongly enhanced due to the He gas cooling. It is experimentally found that helium gas contact effectively lowers electron temperature of the Ar plasma jet. The mechanisms giving rise to population inversion are discussed in terms of atomic collisional processes of the recombining plasma. The experimental results of electron temperature and population densities are discussed by simple numerical analysis which we previously developed. It is shown that the experimental results are well explained by our modeling quantitatively for the case without gas contact, except that the agreement of number densities of lower lying non-LTE levels is qualitative for the case with the gas contact

Preliminary assessment of the waveform inversion method for interpretation of cross-well seismic data from the thermal production test, JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T. [Nagoya Univ., Nagoya (Japan). Research Center for Seismology and Volcanology; Shimizu, S. [Japan National Oil Co., Chiba (Japan); Asakawa, E. [JGI Inc., Tokyo (Japan); Kamei, R.; Matsuoka, T. [Kyoto Univ., Kyoto (Japan). Dept. of Civil and Earth Resources Engineering

2005-07-01

The JAPEX/JNOC/GSC et al. Mallik 3L-38 and 4L-38 test wells were subjected to repeated cross-well seismic surveys before and during the gas production test from the gas-hydrate-bearing layer at a depth of about 905 to 920 m. High-resolution velocity images in the gas-hydrate-bearing layer were obtained using the frequency-domain nonlinear waveform inversion method. An acoustic waveform inversion method was used along with the frequency-domain approach in order to detect the change in acoustic properties of the gas-hydrate-bearing layer resulting from gas production. The layered structures with small lateral heterogeneities were reconstructed by tomography analysis of preprocessed waveform data using a smaller number of source-receiver pairs. Preliminary results reveal high velocity and very high attenuation in the gas-hydrate-bearing layers. No obvious velocity decreases were noted. Information for further detailed processing was also gathered.

TOPICAL REVIEW: Physics and phenomena in pulsed magnetrons: an overview

Science.gov (United States)

Bradley, J. W.; Welzel, T.

2009-05-01

This paper reviews the contribution made to the observation and understanding of the basic physical processes occurring in an important type of magnetized low-pressure plasma discharge, the pulsed magnetron. In industry, these plasma sources are operated typically in reactive mode where a cathode is sputtered in the presence of both chemically reactive and noble gases typically with the power modulated in the mid-frequency (5-350 kHz) range. In this review, we concentrate mostly, however, on physics-based studies carried out on magnetron systems operated in argon. This simplifies the physical-chemical processes occurring and makes interpretation of the observations somewhat easier. Since their first recorded use in 1993 there have been more than 300 peer-reviewed paper publications concerned with pulsed magnetrons, dealing wholly or in part with fundamental observations and basic studies. The fundamentals of these plasmas and the relationship between the plasma parameters and thin film quality regularly have whole sessions at international conferences devoted to them; however, since many different types of magnetron geometries have been used worldwide with different operating parameters the important results are often difficult to tease out. For example, we find the detailed observations of the plasma parameter (particle density and temperature) evolution from experiment to experiment are at best difficult to compare and at worst contradictory. We review in turn five major areas of studies which are addressed in the literature and try to draw out the major results. These areas are: fast electron generation, bulk plasma heating, short and long-term plasma parameter rise and decay rates, plasma potential modulation and transient phenomena. The influence of these phenomena on the ion energy and ion energy flux at the substrate is discussed. This review, although not exhaustive, will serve as a useful guide for more in-depth investigations using the referenced

Reducing the impurity incorporation from residual gas by ion bombardment during high vacuum magnetron sputtering

International Nuclear Information System (INIS)

Rosen, Johanna; Widenkvist, Erika; Larsson, Karin; Kreissig, Ulrich; Mraz, Stanislav; Martinez, Carlos; Music, Denis; Schneider, J. M.

2006-01-01

The influence of ion energy on the hydrogen incorporation has been investigated for alumina thin films, deposited by reactive magnetron sputtering in an Ar/O 2 /H 2 O environment. Ar + with an average kinetic energy of ∼5 eV was determined to be the dominating species in the plasma. The films were analyzed with x-ray diffraction, x-ray photoelectron spectroscopy, and elastic recoil detection analysis, demonstrating evidence for amorphous films with stoichiometric O/Al ratio. As the substrate bias potential was increased from -15 V (floating potential) to -100 V, the hydrogen content decreased by ∼70%, from 9.1 to 2.8 at. %. Based on ab initio calculations, these results may be understood by thermodynamic principles, where a supply of energy enables surface diffusion, H 2 formation, and desorption [Rosen et al., J. Phys.: Condens. Matter 17, L137 (2005)]. These findings are of importance for the understanding of the correlation between ion energy and film composition and also show a pathway to reduce impurity incorporation during film growth in a high vacuum ambient

Development of a Magnetron Resonance Frequency Auto Tuning System for Medical Xband [9300 MHz] RF Linear Accelerator

Energy Technology Data Exchange (ETDEWEB)

Cha, Sung Su; Lee, Byung Cheol [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Yujong; Park, Hyung Dal; Lee, Byeong-No; Joo, Youngwoo; Cha, Hyungki; Lee, Soo Min; Song, Ki Baek [KAERI, Daejeon (Korea, Republic of); Lee, Seung Hyun [Sungkyunkwan University, Suwon (Korea, Republic of)

2015-05-15

The total components of the accelerator are the magnetron, electron gun, accelerating structure, a set of solenoid magnets, four sets of steering coils, a modulator, and a circulator. One of the accelerator components of the accelerating structure is made of oxygen-free high-conductivity copper (OFHC), and its volume is changed according to the ambient temperature. As the volume changes, the resonant frequency of the accelerating structure is changed. Accordingly, the resonance frequency is mismatched between the source of the magnetron and the accelerating structure. An automatic frequency tuning system is automatically matched with the resonant frequency of the magnetron and accelerating structure, which allows a high output power and reliable accelerator operation. An automatic frequency tuning system is composed of a step motor control part for correcting the frequency of the source and power measuring parts, i.e., the forward and reflected power between the magnetron and accelerating structure. In this paper, the design, fabrication, and RF power test of the automatic frequency tuning system for the X-band linac are presented. A frequency tuning system was developed to overcome an unstable accelerator operation owing to the frequency mismatch between the magnetron and accelerating structure. The frequency measurement accuracy is 100 kHz and 0.72 degree per pulse.

Reconstruction of the static magnetic field of a magnetron

Science.gov (United States)

Krüger, Dennis; Köhn, Kevin; Gallian, Sara; Brinkmann, Ralf Peter

2018-06-01

The simulation of magnetron discharges requires a quantitatively correct mathematical model of the magnetic field structure. This study presents a method to construct such a model on the basis of a spatially restricted set of experimental data and a plausible a priori assumption on the magnetic field configuration. The example in focus is that of a planar circular magnetron. The experimental data are Hall probe measurements of the magnetic flux density in an accessible region above the magnetron plane [P. D. Machura et al., Plasma Sources Sci. Technol. 23, 065043 (2014)]. The a priori assumption reflects the actual design of the device, and it takes the magnetic field emerging from a center magnet of strength m C and vertical position d C and a ring magnet of strength m R , vertical position d R , and radius R. An analytical representation of the assumed field configuration can be formulated in terms of generalized hypergeometric functions. Fitting the ansatz to the experimental data with a least square method results in a fully specified analytical field model that agrees well with the data inside the accessible region and, moreover, is physically plausible in the regions outside of it. The outcome proves superior to the result of an alternative approach which starts from a multimode solution of the vacuum field problem formulated in terms of polar Bessel functions and vertical exponentials. As a first application of the obtained field model, typical electron and ion Larmor radii and the gradient and curvature drift velocities of the electron guiding center are calculated.

Thermodynamics of poly(7-methoxy-2-acetylbenzofurane methyl methacrylate-co-styrene) and poly(2-acetylbenzofurane methyl methacrylate-co-styrene)-probe interactions at different temperatures by inverse gas chromatography

International Nuclear Information System (INIS)

İlter, Zülfiye; Demir, Abdullah; Kaya, İsmet

2016-01-01

Highlights: • Thermodynamic of methacrylate-co-styrene polymers were studied by the inverse gas chromatography. • The sorption parameters of polymer-solute systems were determined under glass transition temperature of polymers. • The solubility parameter (δ 2 ) of the polymer was obtained from the slope and intercepts. • Flory-Huggins interaction parameter (χ 12 ∞ ) were determined for polymer-solute systems. - Abstract: In this study, some thermodynamic properties of poly(7-methoxy-2-acetylbenzofurane methyl methacrylate-co-styrene) Poly(MABMM-co-St) and poly(2-acetylbenzofurane methyl methacrylate-co-styrene) Poly(ABMM-co-St) were studied by the inverse gas chromatography (IGC) technique. The retention times (t r ) of selected organic probes were determined from the interactions with Poly(MABMM-co-St) and Poly(ABMM-co-St) of four groups of solvents with different chemical natures and polarities. Then, specific volume (V g 0 ) values of probes were calculated at different column temperatures. The glass transition temperatures (T g ) of Poly(MABMM-co-St) and Poly(ABMM-co-St) were found as 393, 413 K from inverse gas chromatography measurements, respectively. Under the glass transition temperatures adsorption heat (ΔH a ) and above the glass transition molar heat (ΔH 1 S ), free energies (ΔG 1 S ) and entropies (ΔS 1 S ) belonging to sorption for every probe were calculated from inverse gas chromatography measurements. The partial molar heat (ΔH 1 ∞ ), partial molar free energy (ΔG 1 ∞ ), Flory-Huggins interaction parameter (χ 12 ∞ ) and weight fraction activity coefficient (a 1 /w 1 ) ∞ , values for infinite dilute solutions were calculated for polymer-probe systems. The solubility parameter (δ 2 ) of the polymer was obtained from the slope and intercepts of Flory-Huggins interaction parameter (χ 12 ∞ ) graphs with solubility parameters (δ 1 ) of probes.

Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Crăciunescu, Corneliu M., E-mail: corneliu.craciunescu@upt.ro; Mitelea, Ion, E-mail: corneliu.craciunescu@upt.ro; Budău, Victor, E-mail: corneliu.craciunescu@upt.ro [Department of Materials and Manufacturing Engineering, Politehnica University of Timisoara (Romania); Ercuţa, Aurel [Department of Materials and Manufacturing Engineering, Politehnica University of Timisoara and Department of Physics, West University Timisoara (Romania)

2014-11-24

Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

Properties of H- and D- beams from magnetron and Penning sources

International Nuclear Information System (INIS)

Sluyters, T.; Kovarik, V.

1979-01-01

The quality of negative hydrogen isotope beams are evaluated after extraction from magnetron and Penning sources. The general conclusions of these measurements are that: (a) the beam quality from these plasma sources are adequate for the transport of high current negative ion beams in bending magnets; (b) there is evidence of practically complete space charge neutralization in the drift space beyond the extractor; (c) the beam performance from the Penning source appears to be better compared with the magnetron source; and (d) it is likely that the high electric field gradient and a concave ion emission boundary are responsible for a beam cross-over near the anode aperture, which causes beam divergence practically independent of the extraction geometry

On the inverse Magnus effect in free molecular flow

Science.gov (United States)

Weidman, Patrick D.; Herczynski, Andrzej

2004-02-01

A Newton-inspired particle interaction model is introduced to compute the sideways force on spinning projectiles translating through a rarefied gas. The simple model reproduces the inverse Magnus force on a sphere reported by Borg, Söderholm and Essén [Phys. Fluids 15, 736 (2003)] using probability theory. Further analyses given for cylinders and parallelepipeds of rectangular and regular polygon section point to a universal law for this class of geometric shapes: when the inverse Magnus force is steady, it is proportional to one-half the mass M of gas displaced by the body.

Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

Directory of Open Access Journals (Sweden)

L. G. Silva

2014-01-01

Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A; Borderon, C; Tacon, S Le; Averty, D; Gundel, H W

2008-01-01

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi 3.25 La 0.75 Ti 3 O 12 (BLT 0,75 ), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi 3.25 La 0.75 Ti 3 O 12 . After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO 2 /SiO 2 /Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed

High temperature superconducting films by rf magnetron sputtering

International Nuclear Information System (INIS)

Kadin, A.M.; Ballentine, P.H.

1989-01-01

The authors have produced sputtered films of Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O by rf magnetron sputtering from an oxide target consisting of loose reacted powder. The use of a large 8-inch stoichiometric target in the magnetron mode permits films located above the central region to be free of negative-ion resputtering effects, and hence yields reproducible, uniform stoichiometric compositions for a wide range of substrate temperatures. Superconducting YBCO films have been obtained either by sputtering at low temperatures followed by an 850 0 C oxygen anneal, or alternatively by depositing onto substrates heated to ∼600 - 650 0 C and cooling in oxygen. Films prepared by the former method on cubic zirconia substrate consist of randomly oriented crystallites with zero resistance above 83 K. Those deposited on zirconia at medium temperatures without the high-temperature anneal contain smooth partially oriented crystallites, with a slightly depressed T/sub c/ ∼75K. Finally, superconducting films have been deposited on MgO using a BiSrCaCu/sub 2/O/sub x/ powder target

Hybrid plasma system for magnetron deposition of coatings with ion assistance

International Nuclear Information System (INIS)

Vavilin, K V; Kralkina, E A; Nekludova, P A; Petrov, A. K; Nikonov, A M; Pavlov, V B; Airapetov, A A; Odinokov, V V; Pavlov, G Ya; Sologub, V A

2016-01-01

The results of the study of the plasma hybrid system based on the combined magnetron discharge and high-frequency inductive discharge located in the external magnetic field is presented. Magnetron discharge provides the generation of atoms and ions of the target materials while the flow of accelerated ions used for the ion assistance is provided by the RF inductive discharge. An external magnetic field is used to optimize the power input to the discharge, to increase the ion current density in the realm of substrate and to enhance the area of uniform plasma. The joint operation of magnetron and RF inductive discharge leads to a substantial increase (not equal to the sum of the parameters obtained under separate operation of two hybrid system channels) of the ion current density and intensity of sputtered material spectral lines radiation. Optimal mode of the hybrid plasma system operation provides uniform ion current density on the diameter of at least 150mm at 0.7PA argon pressure. The optimal values of the magnetic fields in the region of the substrate location lie in the range 2-8 mTl, while in the region of the RF input power unit lie in the range 0.5-25 mTl. (paper)

Setup for in situ X-ray diffraction studies of thin film growth by magnetron sputtering

CERN Document Server

Ellmer, K; Weiss, V; Rossner, H

2001-01-01

A novel method is described for the in situ-investigation of nucleation and growth of thin films during magnetron sputtering. Energy dispersive X-ray diffraction with synchrotron light is used for the structural analysis during film growth. An in situ-magnetron sputtering chamber was constructed and installed at a synchrotron radiation beam line with a bending magnet. The white synchrotron light (1-70 keV) passes the sputtering chamber through Kapton windows and hits one of the substrates on a four-fold sample holder. The diffracted beam, observed under a fixed diffraction angle between 3 deg. and 10 deg., is energy analyzed by a high purity Ge-detector. The in situ-EDXRD setup is demonstrated for the growth of tin-doped indium oxide (ITO) films prepared by reactive magnetron sputtering from a metallic target.

Multi-gas interaction modeling on decorated semiconductor interfaces: A novel Fermi distribution-based response isotherm and the inverse hard/soft acid/base concept

Science.gov (United States)

Laminack, William; Gole, James

2015-12-01

A unique MEMS/NEMS approach is presented for the modeling of a detection platform for mixed gas interactions. Mixed gas analytes interact with nanostructured decorating metal oxide island sites supported on a microporous silicon substrate. The Inverse Hard/Soft acid/base (IHSAB) concept is used to assess a diversity of conductometric responses for mixed gas interactions as a function of these nanostructured metal oxides. The analyte conductometric responses are well represented using a combination diffusion/absorption-based model for multi-gas interactions where a newly developed response absorption isotherm, based on the Fermi distribution function is applied. A further coupling of this model with the IHSAB concept describes the considerations in modeling of multi-gas mixed analyte-interface, and analyte-analyte interactions. Taking into account the molecular electronic interaction of both the analytes with each other and an extrinsic semiconductor interface we demonstrate how the presence of one gas can enhance or diminish the reversible interaction of a second gas with the extrinsic semiconductor interface. These concepts demonstrate important considerations in the array-based formats for multi-gas sensing and its applications.

Influence of the microstructure on the corrosion behavior of magnetron sputter-quenched amorphous metallic alloys

Science.gov (United States)

Thakoor, A. P.; Khanna, S. K.; Williams, R. M.; Landel, R. F.

1983-01-01

The microstructure and corrosion behavior of magnetron sputter deposited amorphous metallic films of (Mo6ORu40)82B18 under varying sputtering atmospheres have been investigated. The microstructural details and topology of the films have been studied by scanning electron microscopy and correlated with the deposition conditions. By reducing the pressure of pure argon gas, the characteristic features of rough surface and columnar growth full of vertical voids can be converted into a mirror-smooth finish with very dense deposits. Films deposited in the presence of O2 or N2 exhibit columnar structure with vertical voids. Film deposited in pure argon at low pressure show remarkably high corrosion resistance due to the formation of a uniform passive surface layer. The influence of the microstructure and surface texture on the corrosion behavior is discussed.

Structural and tribological properties of CrTiAlN coatings on Mg alloy by closed-field unbalanced magnetron sputtering ion plating

International Nuclear Information System (INIS)

Shi Yongjing; Long Siyuan; Yang Shicai; Pan Fusheng

2008-01-01

In this paper, a series of multi-layer hard coating system of CrTiAlN has been prepared by closed-field unbalanced magnetron sputtering ion plating (CFUBMSIP) technique in a gas mixture of Ar + N 2 . The coatings were deposited onto AZ31 Mg alloy substrates. During deposition step, technological temperature and metallic atom concentration of coatings were controlled by adjusting the currents of different metal magnetron targets. The nitrogen level was varied by using the feedback control of plasma optical emission monitor (OEM). The structural, mechanical and tribological properties of coatings were characterized by means of X-ray photoelectron spectrometry, high-resolution transmission electron microscope, field emission scanning electron microscope (FESEM), micro-hardness tester, and scratch and ball-on-disc tester. The experimental results show that the N atomic concentration increases and the oxide on the top of coatings decreases; furthermore the modulation period and the friction coefficient decrease with the N 2 level increasing. The outstanding mechanical property can be acquired at medium N 2 level, and the CrTiAlN coatings on AZ31 Mg alloy substrates outperform the uncoated M42 high speed steel (HSS) and the uncoated 316 stainless steel (SS)

Investigation of the physical properties of ion assisted ZrN thin films deposited by RF magnetron sputtering

International Nuclear Information System (INIS)

Signore, M A; Valerini, D; Rizzo, A; Tapfer, L; Capodieci, L; Cappello, A

2010-01-01

Ion bombardment during thin film growth is known to cause structural and morphological changes in the deposited films, thus affecting their physical properties. In this work zirconium nitride films have been deposited by the ion assisted magnetron sputtering technique. The ion energy is controlled by varying the voltage applied to the substrate in the range 0-25 V. The deposited ZrN films are characterized for their structure, surface roughness, oxygen contamination, optical reflectance and electrical resistivity. With increasing substrate voltage crystallinity of the films is enhanced with a preferential orientation of the ZrN grains having the (1 1 1) axis perpendicular to the substrate surface. At the same time, a decrease in electrical resistivity and oxygen contamination content is observed up to 20 V. A higher substrate voltage (25 V) causes an inversion in the observed experimental trends. The role of oxygen contamination decrease and generation of nitrogen vacancies due to ionic assistance have been considered as a possible explanation for the experimental results.

Investigation of the physical properties of ion assisted ZrN thin films deposited by RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Signore, M A; Valerini, D; Rizzo, A; Tapfer, L; Capodieci, L; Cappello, A [ENEA, Department of Physical Technologies and New Materials, SS7, Appia, km 706, 72100 Brindisi (Italy)

2010-06-09

Ion bombardment during thin film growth is known to cause structural and morphological changes in the deposited films, thus affecting their physical properties. In this work zirconium nitride films have been deposited by the ion assisted magnetron sputtering technique. The ion energy is controlled by varying the voltage applied to the substrate in the range 0-25 V. The deposited ZrN films are characterized for their structure, surface roughness, oxygen contamination, optical reflectance and electrical resistivity. With increasing substrate voltage crystallinity of the films is enhanced with a preferential orientation of the ZrN grains having the (1 1 1) axis perpendicular to the substrate surface. At the same time, a decrease in electrical resistivity and oxygen contamination content is observed up to 20 V. A higher substrate voltage (25 V) causes an inversion in the observed experimental trends. The role of oxygen contamination decrease and generation of nitrogen vacancies due to ionic assistance have been considered as a possible explanation for the experimental results.

Chromium-nanodiamond coatings obtained by magnetron sputtering and their tribological properties

Science.gov (United States)

Atamanov, M. V.; Khrushchov, M. M.; Marchenko, E. A.; Shevchenko, N. V.; Levin, I. S.; Petrzhik, M. I.; Miroshnichenko, V. I.; Relianu, M. D.

2017-07-01

Peculiarities of structure, chemical and phase composition, micromechanical and tribological properties of chromium-based coatings obtained by magnetron-sputtering of composite and/or compacted chromium-nanodiamond targets have been investigated.

Corrosion of thin, magnetron sputtered Nb_2O_5 films

International Nuclear Information System (INIS)

Pillis, Marina Fuser; Geribola, Guilherme Altomari; Scheidt, Guilherme; Gonçalves de Araújo, Edval; Lopes de Oliveira, Mara Cristina; Antunes, Renato Altobelli

2016-01-01

Highlights: • Niobium oxide based films were obtained by DC magnetron sputtering. • Different deposition times were tested. • The best corrosion resistance was obtained for the Nb_2O_5 film produced at 15′. • Film porosity determines the corrosion resistance. - Abstract: Niobium oxide based thin films were deposited on AISI 316 stainless steel substrates using reactive DC magnetron sputtering. Structure, composition and corrosion resistance of the niobium oxide films were studied. The corrosion behavior of the specimens was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The concentration of niobium and oxygen in the films was obtained by Rutherford backscattering spectroscopy (RBS). The film structure was analyzed by X-ray diffractometry. The corrosion resistance of the substrate was improved by the Nb_2O_5 layers. The best protective performance was achieved for the deposition time of 15 min.

Simulation of the electric potential and plasma generation coupling in magnetron sputtering discharges

Science.gov (United States)

Trieschmann, Jan; Krueger, Dennis; Schmidt, Frederik; Brinkmann, Ralf Peter; Mussenbrock, Thomas

2016-09-01

Magnetron sputtering typically operated at low pressures below 1 Pa is a widely applied deposition technique. For both, high power impulse magnetron sputtering (HiPIMS) as well as direct current magnetron sputtering (dcMS) the phenomenon of rotating ionization zones (also referred to as spokes) has been observed. A distinct spatial profile of the electric potential has been associated with the latter, giving rise to low, mid, and high energy groups of ions observed at the substrate. The adherent question of which mechanism drives this process is still not fully understood. This query is approached using Monte Carlo simulations of the heavy particle (i.e., ions and neutrals) transport consistently coupled to a pre-specified electron density profile via the intrinsic electric field. The coupling between the plasma generation and the electric potential, which establishes correspondingly, is investigated. While the system is observed to strive towards quasi-neutrality, distinct mechanisms governing the shape of the electric potential profile are identified. This work is supported by the German Research Foundation (DFG) in the frame of the transregional collaborative research centre TRR 87.

Catalytic growth of ZnO nanostructures by r.f. magnetron sputtering

Directory of Open Access Journals (Sweden)

Arroyo-Hernández María

2011-01-01

Full Text Available Abstract The catalytic effect of gold seed particles deposited on a substrate prior to zinc oxide (ZnO thin film growth by magnetron sputtering was investigated. For this purpose, selected ultra thin gold layers, with thicknesses close to the percolation threshold, are deposited by thermal evaporation in ultra high vacuum (UHV conditions and subsequently annealed to form gold nanodroplets. The ZnO structures are subsequently deposited by r.f. magnetron sputtering in a UHV chamber, and possible morphological differences between the ZnO grown on top of the substrate and on the gold are investigated. The results indicate a moderate catalytic effect for a deposited gold underlayer of 4 nm, quite close to the gold thin film percolation thickness.

RF Reactive Magnetron Sputter Deposition of Silicon Sub-Oxides

NARCIS (Netherlands)

Hattum, E.D. van

2007-01-01

RF reactive magnetron plasma sputter deposition of silicon sub oxide E.D. van Hattum Department of Physics and Astronomy, Faculty of Sciences, Utrecht University The work described in the thesis has been inspired and stimulated by the use of SiOx layers in the direct inductive printing technology,

Characteristics of a-IGZO/ITO hybrid layer deposited by magnetron sputtering.

Science.gov (United States)

Bang, Joon-Ho; Park, Hee-Woo; Cho, Sang-Hyun; Song, Pung-Keun

2012-04-01

Transparent a-IGZO (In-Ga-Zn-O) films have been actively studied for use in the fabrication of high-quality TFTs. In this study, a-IGZO films and a-IGZO/ITO double layers were deposited by DC magnetron sputtering under various oxygen flow rates. The a-IGZO films showed an amorphous structure up to 500 degrees C. The deposition rate of these films decreased with an increase in the amount of oxygen gas. The amount of indium atoms in the film was confirmed to be 11.4% higher than the target. The resistivity of double layer follows the rules for parallel DC circuits The maximum Hall mobility of the a-IGZO/ITO double layers was found to be 37.42 cm2/V x N s. The electrical properties of the double layers were strongly dependent on their thickness ratio. The IGZO/ITO double layer was subjected to compressive stress, while the ITO/IGZO double layer was subjected to tensile stress. The bending tolerance was found to depend on the a-IGZO thickness.

Theory of the inverse Faraday effect in metals

International Nuclear Information System (INIS)

Hertel, Riccardo

2006-01-01

An analytic expression is given for the inverse Faraday effect, i.e., for the magnetization occurring in a transparent medium exposed to a circularly polarized high-frequency electromagnetic wave. Using a microscopic approach based on the Drude approximation of a free-electron gas, the magnetization of the medium due to the inverse Faraday effect is identified as the result of microscopic solenoidal currents generated by the electromagnetic wave. In contrast to the better known phenomenological derivation, this microscopic treatment provides important information on the frequency dependence of the inverse Faraday effect

ZnO:Al Thin Film Gas Sensor for Detection of Ethanol Vapor

Directory of Open Access Journals (Sweden)

Min Hsiung Hon

2006-10-01

Full Text Available The ZnO:Al thin films were prepared by RF magnetron sputtering on Si substrateusing Pt as interdigitated electrodes. The structure was characterized by XRD and SEManalyses, and the ethanol vapor gas sensing as well as electrical properties have beeninvestigated and discussed. The gas sensing results show that the sensitivity for detecting400 ppm ethanol vapor was ~20 at an operating temperature of 250°C. The high sensitivity,fast recovery, and reliability suggest that ZnO:Al thin film prepared by RF magnetronsputtering can be used for ethanol vapor gas sensing.

Electrical and optical study of transparent V-based oxide semiconductors prepared by magnetron sputtering under different conditions

Directory of Open Access Journals (Sweden)

E. Prociow

2011-04-01

Full Text Available This work is focused on structural, optical and electrical behaviors of vanadium-based oxide thin films prepared by magnetron sputtering under different conditions. Thin films have been deposited on glass substrates from metallic vanadium target at low sputtering pressure. Different working gases: argon/oxygen mixture, and especially pure oxygen gas, have been applied. Results of X-ray diffraction together with optical transmission and temperature- dependent electrical resistivity measurements have been presented. Transmission coefficient, cut-off wavelength and the width of the optical band gap have been calculated from optical measurements. The d.c. resistivity values at room temperature and thermal activation energy have been obtained from electrical investigations. The influence of sputtering process conditions on optical and electrical properties has been discussed.

Low resistivity of Ni–Al co-doped ZnO thin films deposited by DC magnetron sputtering at low sputtering power

Energy Technology Data Exchange (ETDEWEB)

Lee, JongWoo [Department of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Hui, K.N. [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Hui, K.S., E-mail: kshui@hanyang.ac.kr [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Cho, Y.R., E-mail: yescho@pusan.ac.kr [Department of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Chun, Ho-Hwan [Global Core Research Center for Ships and Offshore Plants (GCRC-SOP), Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

2014-02-28

Ni–Al co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates by DC magnetron sputtering in Ar using a single ceramic, spark-plasma-sintered target with 2 wt% Al and 5 wt% Ni. The effects of the sputtering power and gas pressure on the NiAl:ZnO films were studied. The structural, electrical, and optical properties of the films were characterized by X-ray diffraction, field emission scanning electron microscopy, Hall effect measurements and UV–vis transmission spectroscopy. As the sputtering power and gas pressure increased, the crystallinity, electrical properties and optical band gap of the films were improved. The NiAl:ZnO film deposited at 40 W at 6.0 mTorr had the strongest (0 0 2) XRD peak and the lowest resistivity of approximately 2.19 × 10{sup −3} Ω cm with an optical transmittance of 90%.

Functional nanostructured titanium nitride films obtained by sputtering magnetron

International Nuclear Information System (INIS)

Sanchez, O.; Hernandez-Velez, M.; Navas, D.; Auger, M.A.; Baldonedo, J.L.; Sanz, R.; Pirota, K.R.; Vazquez, M.

2006-01-01

Development of new methods in the formation of hollow structures, in particular, nanotubes and nanocages are currently generating a great interest as a consequence of the growing relevance of these nanostructures on many technological fields, ranging from optoelectronics to biotechnology. In this work, we report the formation of titanium nitride (TiN) nanotubes and nanohills via reactive sputtering magnetron processes. Anodic Alumina Membranes (AAM) were used as template substrates to grow the TiN nanostructures. The AAM were obtained through electrochemical anodization processes by using oxalic acid solutions as electrolytes. The nanotubes were produced at temperatures below 100 deg. C, and using a pure titanium (99.995%) sputtering target and nitrogen as reactive gas. The obtained TiN thin films showed surface morphologies adjusted to pore diameter and interpore distance of the substrates, as well as ordered arrays of nanotubes or nanohills depending on the sputtering and template conditions. High Resolution Scanning Electron Microscopy (HRSEM) was used to elucidate both the surface order and morphology of the different grown nanostructures. The crystalline structure of the samples was examined using X-ray Diffraction (XRD) patterns and their qualitative chemical composition by using X-ray Energy Dispersive Spectroscopy (XEDS) in a scanning electron microscopy

High temperature oxidation resistance of magnetron-sputtered homogeneous CrAlON coatings on 430 steel

Energy Technology Data Exchange (ETDEWEB)

Garratt, E; Wickey, K J; Nandasiri, M I; Moore, A; AlFaify, S; Gao, X [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States); Smith, R J; Buchanan, T L; Priyantha, W; Kopczyk, M; Gannon, P E [Montana State University, Bozeman, MT, 59717 (United States); Kayani, A, E-mail: asghar.kayani@wmich.ed

2009-11-01

The requirements of low cost and high-temperature corrosion resistance for bipolar interconnect plates in solid oxide fuel cell stacks has directed attention to the use of metal plates with oxidation resistant coatings. We have investigated the performance of steel plates with homogenous coatings of CrAlON (oxynitrides). The coatings were deposited using RF magnetron sputtering, with Ar as a sputtering gas. Oxygen in these coatings was not intentionally added. Oxygen might have come through contaminated nitrogen gas bottle, leak in the chamber or from the partial pressure of water vapors. Nitrogen was added during the growth process to get oxynitride coating. The Cr/Al composition ratio in the coatings was varied in a combinatorial approach. The coatings were subsequently annealed in air for up to 25 hours at 800 {sup o}C. The composition of the coated plates and the rate of oxidation were characterized using Rutherford backscattering (RBS) and nuclear reaction analysis (NRA). Surface characterization was carried out using Atomic Force Microscopy (AFM) and surfaces of the coatings were found smooth on submicron scale. From our results, we conclude that Al rich coatings are more susceptible to oxidation than Cr rich coatings.

Preparation of basil seed mucilage aerogels loaded with paclitaxel nanoparticles by the combination of phase inversion technique and gas antisolvent process

Directory of Open Access Journals (Sweden)

Seyyed Ghoreishi

2017-09-01

Full Text Available Objective(S: In this work, paclitaxel (PX, a promising anticancer drug, was loaded in the basil seed mucilage (BSM aerogels by implementation of supercritical carbon dioxide (SC-CO2 technology. Then, the effects of operating conditions were studied on the PX mean particle size (MPS, particle size distribution (PSD and drug loading efficiency (DLE. Methods: The employed SC-CO2 process in this research is the combination of phase inversion technique and gas antisolvent (GAS process. The effect of DMSO/water ratio (4 and 6 (v/v, pressure (10-20 MPa, CO2 addition rate (1–3 mL/min and ethanol concentration (5-10% were studied on MPS, PSD and DLE. Scanning electron microscopy (SEM and Zetasizer were used for particle analysis. DLE was investigated by utilizing the high-performance liquid chromatography (HPLC. Results: Nanoparticles of paclitaxel (MPS of 82–131 nm depending on process variables with narrow PSD were successfully loaded in BSM aerogel with DLE of 28–52%. Experimental results indicated that higher DMSO/water ratio, ethanol concentration, pressure and CO2 addition rate reduced MPS and DLE. Conclusions: A modified semi batch SC-CO2 process based on the combination of gas antisolvent process and phase inversion methods using DMSO as co-solvent and ethanol as a secondary solvent was developed for the loading of an anticancer drug, PX, in ocimum basilicum mucilage aerogel. The experimental results determined that the mean particle size, particle size distribution, and drug loading efficiency be controlled with operating conditions.

Magnetron co-sputtering system for coating ICF targets

International Nuclear Information System (INIS)

Hsieh, E.J.; Meyer, S.F.; Halsey, W.G.; Jameson, G.T.; Wittmayer, F.J.

1981-01-01

Fabrication of Inertial Confinement Fusion (ICF) targets requires deposition of various types of coatings on microspheres. The mechanical strength, and surface finish of the coatings are of concern in ICF experiments. The tensile strength of coatings can be controlled through grain refinement, selective doping and alloy formation. We have constructed a magnetron co-sputtering system to produce variable density profile coatings with high tensile strength on microspheres

Special traits of the millimeter wave relativistic magnetron

International Nuclear Information System (INIS)

Berdin, S.A.; Chizhov, K.V.; Gadetski, N.P.; Korenev, V.G.; Lebedenko, A.N.; Marchenko, M.I.; Magda, I.I.; Melezhik, O.G.; Sinitsin, V.G.; Soshenko, V.A.

2014-01-01

A 8 mm band relativistic magnetron is investigated experimentally and by means of numerical simulation. The physical effects are analyzed which influence negatively the r.f. generation. The processes capable of reducing effectiveness of the generation and duration of the generated pulse include forward and backward axial flows of electrons, and intense electric fields - the generated microwaves and the fields owing to the space charge

The action of cellulose-based and conventional flotation reagents under dry and wet conditions correlating inverse gas chromatography to microflotation studies

OpenAIRE

Hartmann, R. (R.); Rudolph, M. (M.); Ämmälä, A. (A.); Illikainen, M. (M.)

2017-01-01

Abstract The fundamental formation of the three phase contact in flotation is an intensively and controversially discussed phenomenon and the contact angle method is usually employed to characterise the wettability of solid surfaces. A more recent technique to explore the hydrophobicity of solid particulate phases is inverse gas chromatography (iGC) which is used to quantify the wettability of solid surfaces through thermodynamic parameters. In this article, the recently introduced net fre...

Status and prospects of a compact FIR FEL driven by a magnetron-based microtron

International Nuclear Information System (INIS)

Jeong, Young Uk; Kazakevitch, Grigori M.; Lee, Byung Cheol; Kim, Sun Kook; Cho, Sung Oh; Gavrilov, Nicolai G.; Lee, Jongmin

2002-01-01

A magnetron-based microtron as a driver of FIR FEL has several prominent advantages in cost, size, beam quality and operation convenience. However, it has some disadvantages due to the instability of the RF frequency and a low current. In order to overcome these disadvantages, the frequency stability of the magnetron was improved, and the interaction between the electron beam and the FIR radiation was enhanced by using a high-performance undulator and a low-loss waveguide-mode optical resonator. The FEL is now under upgrade in order to extend the wavelength range to cover 90-300 μm, which can be done by increasing the energy range of electron beam to 4.3-7 MeV. In this paper, we report the results of investigations on output characteristics of the FEL depending on cavity detuning, electron beam matching, and RF instability. Based on the results, we discuss the prospects of wide-band FIR FELs driven by magnetron-based microtrons as potent sources of radiation for scientific applications

Fabrication and characterization of flaky core-shell particles by magnetron sputtering silver onto diatomite

Science.gov (United States)

Wang, Yuanyuan; Zhang, Deyuan; Cai, Jun

2016-02-01

Diatomite has delicate porous structures and various shapes, making them ideal templates for microscopic core-shell particles fabrication. In this study, a new process of magnetron sputtering assisted with photoresist positioning was proposed to fabricate lightweight silver coated porous diatomite with superior coating quality and performance. The diatomite has been treated with different sputtering time to investigate the silver film growing process on the surface. The morphologies, constituents, phase structures and surface roughness of the silver coated diatomite were analyzed with SEM, EDS, XRD and AFM respectively. The results showed that the optimized magnetron sputtering time was 8-16 min, under which the diatomite templates were successfully coated with uniform silver film, which exhibits face centered cubic (fcc) structure, and the initial porous structures were kept. Moreover, this silver coating has lower surface roughness (RMS 4.513 ± 0.2 nm) than that obtained by electroless plating (RMS 15.692 ± 0.5 nm). And the infrared emissivity of coatings made with magnetron sputtering and electroless plating silver coated diatomite can reach to the lowest value of 0.528 and 0.716 respectively.

Thermodynamic properties of hyperbranched polymer, Boltorn U3000, using inverse gas chromatography.

Science.gov (United States)

Domańska, Urszula; Zołek-Tryznowska, Zuzanna

2009-11-19

Mass-fraction activity coefficients at infinite dilution (Omega13(infinity)) of alkanes (C5-C10), cycloalkanes (C5-C8), alkenes (C5-C8), alkynes (C5-C8), aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-, m-, p-xylene, thiophene), alcohols (C1-C5), water, ethers (tetrahydrofuran (THF), methyl-tert-butylether (MTBE), diethyl-, di-n-propyl-, di-n-butyl ether), and ketones (propanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, cyclopentanone) in the hyperbranched polymer, Boltorn U3000 (B-U3000), have been determined by inverse gas chromatography (IGC) using the polymer as the stationary phase. The measurements were carried out at different temperatures between 308.15 and 348.15 K. The density and thermophysical properties of polymer were described. The specific retention volume (V(g)), the Flory-Huggins interaction parameter (chi13(infinity)), the molar enthalpy of sorption (the partial molar enthalpies of solute dissolution) (Delta(s)H), the partial molar excess enthalpy at infinite dilution of the solute and polymer (DeltaH1(E,infinity)), the partial molar Gibbs excess energy at infinite dilution (DeltaG1(E,infinity)), and the solubility parameter (delta3) were calculated.

Experimental study on an S-band near-field microwave magnetron power transmission system on hundred-watt level

Science.gov (United States)

Zhang, Biao; Jiang, Wan; Yang, Yang; Yu, Chengyang; Huang, Kama; Liu, Changjun

2015-11-01

A multi-magnetron microwave source, a metamaterial transmitting antenna, and a large power rectenna array are presented to build a near-field 2.45 GHz microwave power transmission system. The square 1 m2 rectenna array consists of sixteen rectennas with 2048 Schottky diodes for large power microwave rectifying. It receives microwave power and converts them into DC power. The design, structure, and measured performance of a unit rectenna as well as the entail rectenna array are presented in detail. The multi-magnetron microwave power source switches between half and full output power levels, i.e. the half-wave and full-wave modes. The transmission antenna is formed by a double-layer metallic hole array, which is applied to combine the output power of each magnetron. The rectenna array DC output power reaches 67.3 W on a 1.2 Ω DC load at a distance of 5.5 m from the transmission antenna. DC output power is affected by the distance, DC load, and the mode of microwave power source. It shows that conventional low power Schottky diodes can be applied to a microwave power transmission system with simple magnetrons to realise large power microwave rectifying.

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A [Universite de Nantes - Institut des Materiaux Jean Rouxel, UMR CNRS 6502, 2, rue de la Houssiniere BP32229, 44322 Nantes Cedex (France); Borderon, C; Tacon, S Le; Averty, D; Gundel, H W [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, UPRES-EA 1770, IREENA, Universite de Nantes, 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex (France)], E-mail: Marie-Paule.Besland@cnrs-imn.fr

2008-01-15

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}(BLT{sub 0,75}), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}. After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed.

Magnetron based high energy S-band linac system

International Nuclear Information System (INIS)

Tiwari, T.; Krishnan, R.; Phatangare, Manoj

2012-01-01

This paper deals with the study of magnetron based high energy S-band linear accelerator (linac) system operating at spot frequency 2.998 GHz. The energy and dose are two important parameters of linac system which depend on input power of microwave source and length of linac tube. Here the author has studied how these parameters can be improved for side coupled standing wave S-band linac system

Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

Directory of Open Access Journals (Sweden)

Partha Saikia

2016-04-01

Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

High power pulsed magnetron sputtering: A method to increase deposition rate

International Nuclear Information System (INIS)

Raman, Priya; McLain, Jake; Ruzic, David N; Shchelkanov, Ivan A.

2015-01-01

High power pulsed magnetron sputtering (HPPMS) is a state-of-the-art physical vapor deposition technique with several industrial applications. One of the main disadvantages of this process is its low deposition rate. In this work, the authors report a new magnetic field configuration, which produces deposition rates twice that of conventional magnetron's dipole magnetic field configuration. Three different magnet pack configurations are discussed in this paper, and an optimized magnet pack configuration for HPPMS that leads to a higher deposition rate and nearly full-face target erosion is presented. The discussed magnetic field produced by a specially designed magnet assembly is of the same size as the conventional magnet assembly and requires no external fields. Comparison of deposition rates with different power supplies and the electron trapping efficiency in complex magnetic field arrangements are discussed

Electrical properties of AlN{sub x}O{sub y} thin films prepared by reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Borges, J., E-mail: joelborges@fisica.uminho.pt [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal); Martin, N. [Institut FEMTO-ST, Departement MN2S, UMR 6174 (CNRS, UFC, ENSMM, UTBM) 32, Avenue de l' Observatoire 25044 BESANCON Cedex (France); Barradas, N.P.; Alves, E. [Instituto Superior Tecnico, Instituto Tecnologico Nuclear, E.N. 10, 2686-953 Sacavem (Portugal); Eyidi, D.; Beaufort, M.F.; Riviere, J.P. [Institut PPRIME, UPR 3346 CNRS-Universite de Poitiers-ENSMA, Departement de Physique et Mecanique des Materiaux, BP 30179 86962 Chasseneuil-Futuroscope Cedex (France); Vaz, F.; Marques, L. [Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal)

2012-08-31

Direct current magnetron sputtering was used to produce AlN{sub x}O{sub y} thin films, using an aluminum target, argon and a mixture of N{sub 2} + O{sub 2} (17:3) as reactive gases. The partial pressure of the reactive gas mixture was increased, maintaining the discharge current constant. Within the two identified regimes of the target (metallic and compound), four different tendencies for the deposition rate were found and a morphological evolution from columnar towards cauliflower-type, ending up as dense and featureless-type films. The structure was found to be Al-type (face centered cubic) and the structural characterization carried out by X-ray diffraction and transmission electron microscopy suggested the formation of an aluminum-based polycrystalline phase dispersed in an amorphous aluminum oxide/nitride (or oxynitride) matrix. This type of structure, composition, morphology and grain size, were found to be strongly correlated with the electrical response of the films, which showed a gradual transition between metallic-like responses towards semiconducting and even insulating-type behaviors. A group of films with high aluminum content revealed a sharp decrease of the temperature coefficient of resistance (TCR) as the concentration ratio of non-metallic/aluminum atomic ratio increased. Another group of samples, where the non-metallic content became more important, revealed a smooth transition between positive and negative values of TCR. In order to test whether the oxynitride films have a unique behavior or simply a transition between the typical responses of aluminum and of those of the correspondent nitride and oxide, the electrical properties of the ternary oxynitride system were compared with AlN{sub x} and AlO{sub y} systems, prepared in similar conditions. - Highlights: Black-Right-Pointing-Pointer AlN{sub x}O{sub y} thin films were produced using magnetron sputtering. Black-Right-Pointing-Pointer AlN{sub x}O{sub y} film morphology, composition and

Additive manufactured Ti6Al4V scaffolds with the RF- magnetron sputter deposited hydroxyapatite coating

International Nuclear Information System (INIS)

Chudinova, E; Surmeneva, M; Surmenev, R; Koptioug, A; Scoglund, P

2016-01-01

Present paper reports on the results of surface modification of the additively manufactured porous Ti6Al4V scaffolds. Radio frequency (RF) magnetron sputtering was used to modify the surface of the alloy via deposition of the biocompatible hydroxyapatite (HA) coating. The surface morphology, chemical and phase composition of the HA-coated alloy were studied. It was revealed that RF magnetron sputtering allows preparing a homogeneous HA coating onto the entire surface of scaffolds. (paper)

Control of the optical properties of silicon and chromium mixed oxides deposited by reactive magnetron sputtering

International Nuclear Information System (INIS)

Vergara, L.; Galindo, R. Escobar; Martinez, R.; Sanchez, O.; Palacio, C.; Albella, J.M.

2011-01-01

The development of mixed-oxide thin films allows obtaining materials with better properties than those of the different binary oxides, which makes them suitable for a great number of applications in different fields, such as tribology, optics or microelectronics. In this paper we investigate the deposition of mixed chromium and silicon oxides deposited by reactive magnetron sputtering with a view to use them as optical coatings with an adjustable refractive index. These films have been characterized by means of Rutherford backscattering spectrometry, Auger electron spectroscopy, X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy and spectroscopic ellipsometry so as to determine how the deposition conditions influence the characteristics of the material. We have found that the deposition parameter whose influence determines the properties of the films to a greater extent is the amount of oxygen in the reactive sputtering gas.

Electrochromic properties of bipolar pulsed magnetron sputter deposited tungsten–molybdenum oxide films

Energy Technology Data Exchange (ETDEWEB)

Lin, Tai-Nan [Chemical Engineering Division, Institute of Nuclear Energy Research, Taoyuan 325, Taiwan, ROC (China); Lin, Yi Han; Lee, Chin Tan [Department of Electronic Engineering, National Quemoy University, Kinmen 892, Taiwan, ROC (China); Han, Sheng [Center of General Education, National Taichung Institute of Technology, Taichung 404, Taiwan, ROC (China); Weng, Ko-Wei, E-mail: kowei@nqu.edu.tw [Department of Electronic Engineering, National Quemoy University, Kinmen 892, Taiwan, ROC (China)

2015-06-01

There are great interests in electrochromic technology for smart windows and displays over past decades. In this study, the WMoO{sub x} thin films were deposited onto indium tin oxide glass and silicon substrates by pulsed magnetron sputter system with W and Mo targets. The films were deposited with fixed W target power while the variant parameter of Mo target power in the range 50, 100, 150 and 200 W was investigated. The working pressure was fixed at 1.33 Pa with a gas mixture of Ar (30 sccm) and O{sub 2} (15 sccm). The film thickness increased with the Mo target power. Higher plasma power resulted in a crystalline structure which would reduce the electrochromic property of the film. The influence of plasma powers applied to Mo target on the structural, optical and electrochromic properties of the WMoO{sub x} thin films has been investigated. WMoO{sub x} films grown at Mo target powers less than 100 W were found to be amorphous. The films deposited at 150 W, which is the optimal fabrication condition, exhibit better electrochromic properties with high optical modulation, high coloration efficiency and less color memory effect at wavelength 400, 550 and 800 nm. The improvement resulted from the effect of doping Mo has been tested. The maximum ΔT (%) values are 36.6% at 400 nm, 65.6% at 550 nm, and 66.6% at 800 nm for pure WO{sub 3} film. The addition of Mo content in the WMoO{sub x} films provides better resistance to the short wavelength light source and can be used in the concerned application. - Highlights: • WMoO{sub x} films are deposited by pulsed magnetron sputter with pure W and Mo targets. • Mo addition in WMoO{sub x} provides better resistance to short wavelength light source. • WMoO{sub x} films exhibit electrochemical stability in the cycling test.

Blue Diode Laser Absorption Spectroscopy of Pulsed Magnetron Discharge

Czech Academy of Sciences Publication Activity Database

Olejníček, Jiří; Do, H.T.; Hubička, Zdeněk; Hippler, R.; Jastrabík, Lubomír

2006-01-01

Roč. 45, 10B (2006), s. 8090-8094 ISSN 0021-4922 R&D Projects: GA AV ČR 1QS100100563; GA ČR GA202/05/2242 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z10100520 Keywords : laser absorption spectroscopy * pulsed magnetron * sputtering parameters Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.222, year: 2006

Analysis of conditions for magnetron discharge initiation at vacuum camera testing

International Nuclear Information System (INIS)

Tzeneva, Raina; Dineff, Peter; Darjanova, Denitza

2002-01-01

Models of electric field distribution for two typical cases of vacuum camera internal pressure control are investigated. New relations between the maximum magnetron discharge current value I max and the maximum electric field strength radial component value E τ max are established. (Author)

Rutile TiO2 thin films grown by reactive high power impulse magnetron sputtering

International Nuclear Information System (INIS)

Agnarsson, B.; Magnus, F.; Tryggvason, T.K.; Ingason, A.S.; Leosson, K.; Olafsson, S.; Gudmundsson, J.T.

2013-01-01

Thin TiO 2 films were grown on Si(001) substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 °C. Optical and structural properties of films were compared both before and after post-annealing using scanning electron microscopy, low angle X-ray reflection (XRR), grazing incidence X-ray diffractometry and spectroscopic ellipsometry. Both dcMS- and HiPIMS-grown films reveal polycrystalline rutile TiO 2 , even prior to post-annealing. The HiPIMS-grown films exhibit significantly larger grains compared to that of dcMC-grown films, approaching 100% of the film thickness for films grown at 700 °C. In addition, the XRR surface roughness of HiPIMS-grown films was significantly lower than that of dcMS-grown films over the whole temperature range 300–700 °C. Dispersion curves could only be obtained for the HiPIMS-grown films, which were shown to have a refractive index in the range of 2.7–2.85 at 500 nm. The results show that thin, rutile TiO 2 films, with high refractive index, can be obtained by HiPIMS at relatively low growth temperatures, without post-annealing. Furthermore, these films are smoother and show better optical characteristics than their dcMS-grown counterparts. - Highlights: • We demonstrate growth of rutile TiO 2 on Si (111) by high power impulse magnetron sputtering. • The films exhibit significantly larger grains than dc magnetron sputtered films • TiO 2 films with high refractive index are obtained without post-growth annealing

A hybrid electron cyclotron resonance metal ion source with integrated sputter magnetron for the production of an intense Al{sup +} ion beam

Energy Technology Data Exchange (ETDEWEB)

Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Philipp, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

2015-09-15

A metal ion source prototype has been developed: a combination of magnetron sputter technology with 2.45 GHz electron cyclotron resonance (ECR) ion source technology—a so called magnetron ECR ion source (MECRIS). An integrated ring-shaped sputter magnetron with an Al target is acting as a powerful metal atom supply in order to produce an intense current of singly charged metal ions. Preliminary experiments show that an Al{sup +} ion current with a density of 167 μA/cm{sup 2} is extracted from the source at an acceleration voltage of 27 kV. Spatially resolved double Langmuir probe measurements and optical emission spectroscopy were used to study the plasma states of the ion source: sputter magnetron, ECR, and MECRIS plasma. Electron density and temperature as well as Al atom density were determined as a function of microwave and sputter magnetron power. The effect of ECR heating is strongly pronounced in the center of the source. There the electron density is increased by one order of magnitude from 6 × 10{sup 9} cm{sup −3} to 6 × 10{sup 10} cm{sup −3} and the electron temperature is enhanced from about 5 eV to 12 eV, when the ECR plasma is ignited to the magnetron plasma. Operating the magnetron at constant power, it was observed that its discharge current is raised from 1.8 A to 4.8 A, when the ECR discharge was superimposed with a microwave power of 2 kW. At the same time, the discharge voltage decreased from about 560 V to 210 V, clearly indicating a higher plasma density of the MECRIS mode. The optical emission spectrum of the MECRIS plasma is dominated by lines of excited Al atoms and shows a significant contribution of lines arising from singly ionized Al. Plasma emission photography with a CCD camera was used to prove probe measurements and to identify separated plasma emission zones originating from the ECR and magnetron discharge.

1D inversion and analysis of marine controlled-source EM data

DEFF Research Database (Denmark)

Christensen, N.B.; Dodds, Kevin; Bulley, Ian

2006-01-01

been displaced by resistive oil or gas. We present preliminary results from an investigation of the applicability of one-dimensional inversion of the data. A noise model for the data set is developed and inversion is carried out with multi-layer models and 4-layer models. For the data set in question...

Efficiencies of subcritical and transcritical CO2 inverse cycles with and without an internal heat exchanger

International Nuclear Information System (INIS)

Zhang, F.Z.; Jiang, P.X.; Lin, Y.S.; Zhang, Y.W.

2011-01-01

An internal heat exchanger (IHX) is often used to improve the coefficient of performance (COP) of CO 2 inverse cycles. This paper presents a detailed analysis of the IHX's effect in CO 2 inverse cycles and finds suitable operating conditions for the IHX from a thermodynamic performance point of view. The results indicate that the COP is slightly reduced by an IHX in a CO 2 subcritical inverse cycle, so an IHX is not justified. However, for transcritical CO 2 inverse cycles, the compressor discharge pressures and CO 2 gas cooler outlet temperatures both have significant impacts on system performance. The analysis results for transcritical CO 2 inverse cycles show that a transition discharge pressure and a transition CO 2 gas cooler outlet temperature are objective existence above which the IHX improves the cycle performance. - Research highlights: → Find suitable operating conditions for the IHX. → Above transition CO2 gas cooler outlet temperature IHX improves cycle performance. → The IHX is not very useful for optimized space heating and refrigerating cycles.

Gas-discharge sources with charged particle emission from the plasma of glow discharge with a hollow cathode

CERN Document Server

Semenov, A P

2001-01-01

One studied properties of a magnetron discharge with a cold hollow and uncooled rod cathodes. One demonstrated the dominant effect of thermoelectron emission of a rod cathode heated in a discharge on characteristics of discharge and on emission properties of a gas-discharge plasma and the possibility pf a smooth transition of glow discharge to diffusion mode of arc discharge combustion. Paper describes sources of ions and electrons with improved physical and generalized design and engineering parameters. One shows the promise of the electrode structure of a hollow cathode magnetron discharge to be used as a source, in particular, of the atomic hydrogen and of atom flow of a working rod cathode

Indium zinc oxide films deposited on PET by LF magnetron sputtering

International Nuclear Information System (INIS)

Kim, Eun Lyoung; Jung, Sang Kooun; Sohn, Sang Ho; Park, Duck Kyu

2007-01-01

Indium zinc oxide (IZO) has attracted much attention recently for use in transparent oxide films compared with the ITO film. We carried out the deposition of IZO on a polyethylene terapthalate (PET) substrate at room temperature by a low-frequency (LF) magnetron sputtering system. These films have amorphous structures with excellent electrical stability, surface uniformity and high optical transmittance. The effects of LF applied voltage and O 2 flow rate were investigated. The electrical and optical properties were studied. At optimal deposition conditions, thin films of IZO with a sheet resistance of 32 Ω/sq and an optical transmittance of over 80% in the visible spectrum range were achieved. The IZO thin films fabricated by this method do not require substrate heating during the film preparation of any additional post-deposition annealing treatment. The experimental results show that films with good qualities of surface morphology, transmittance and electrical conduction can be grown by the LF magnetron sputtering method on PET which is recommendable

Optimizing electrical conductivity and optical transparency of IZO thin film deposited by radio frequency (RF) magnetron sputtering

Science.gov (United States)

Zhang, Lei

Transparent conducting oxide (TCO) thin films of In2O3, SnO2, ZnO, and their mixtures have been extensively used in optoelectronic applications such as transparent electrodes in solar photovoltaic devices. In this project I deposited amorphous indium-zinc oxide (IZO) thin films by radio frequency (RF) magnetron sputtering from a In2O3-10 wt.% ZnO sintered ceramic target to optimize the RF power, argon gas flowing rate, and the thickness of film to reach the maximum conductivity and transparency in visible spectrum. The results indicated optimized conductivity and transparency of IZO thin film is closer to ITO's conductivity and transparency, and is even better when the film was deposited with one specific tilted angle. National Science Foundation (NSF) MRSEC program at University of Nebraska Lincoln, and was hosted by Professor Jeff Shields lab.

Growth Al{sub x}Ga{sub 1−x}N films on Si substrates by magnetron sputtering and high ammoniated two-step method

Energy Technology Data Exchange (ETDEWEB)

Wang, Xuewen, E-mail: wangxuew@nwu.edu.cn [School of Information Science and Technology, Northwest University, Xi' an 710127 (China); Su, Xingxing; Hu, Feng; He, Lin; He, Lewan; Zhang, Zhiyong; Zhao, Wu [School of Information Science and Technology, Northwest University, Xi' an 710127 (China); Wang, Kai-Ge; Wang, Shuang [Institute of Photonics & Photo-Technology, International Joint Research Centre of Photoelectric Technology & Nano-functional Materials and Application, Northwest University, Xi' an 710069 (China)

2016-05-15

In this paper, Al{sub x}Ga{sub 1−x}N films on Si substrates were synthesized with adjusting process parameters by magnetron sputtering and high ammoniated two-step method innovatively, while gallium oxide was used as gallium target, and aluminum was used as aluminum target, ammonia gas and nitrogen were used as nitrogen source. The influence of process parameters on the quality of Al{sub x}Ga{sub 1−x}N films was researched with X-ray diffraction (XRD), scanning electron microscope (SEM), and Energy Diffraction Spectrum (EDS) for the prepared samples. The results showed that Al{sub x}Ga{sub 1−x}N film can be grown on the Si substrate by magnetron sputtering and high ammoniated two-step method, and substrate temperature, sputtering power, nitrogen concentration also have a great impact on the quality of Al{sub x}Ga{sub 1−x}N film. The sample was developed along (002) peak preferred with high orientation at 200 °C. High-quality film could be grown when the x is 0.32 in Al{sub x}Ga{sub 1−x}N films grown in 300 °C substrate temperature, 150 W sputtering power and 50% nitrogen concentration conditions, which is used for gas sensitive sensor. And compared stress by the measurement of Raman with an excitation wavelength λ = 532 nm. The samples were tested by photoluminescence (PL), which indicated two light-emitting peaks at 405 nm and 645 nm when the excitation wavelength is 325 nm. The measure in Hall Effect Measurement System showed that the carrier concentration and mobility were changed with different Al components. - Highlights: • Grow Al{sub 0.32}Ga{sub 0.68}N films on Si by RF sputtering and high ammoniated two-step method. • The sample was developed along (002) peak preferred with high orientation at 200 °C. • The growth technics of the film was employed for the preparation of gas sensors. • Carrier concentration and mobility were changed with different Al components.

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

International Nuclear Information System (INIS)

Biederman, H.; Holland, L.

1983-01-01

Fluorocarbon films have been prepared by plasma polymerization of CF 4 using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an r.f. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF 4 [25%]-argon[75%] mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF 4 [87%]-argon[13%] were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF 4 as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined. (orig.)

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

Energy Technology Data Exchange (ETDEWEB)

Biederman, H.; Holland, L. (Sussex Univ., Brighton (UK). Lab. for Plasma Materials Processing)

1983-07-01

Fluorocarbon films have been prepared by plasma polymerization of CF/sub 4/ using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an R.F. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF/sub 4/(25%)-argon(75%) mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF/sub 4/(87%)-argon(13%) were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF/sub 4/ as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined.

Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

Science.gov (United States)

Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

2016-09-30

A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well. Copyright © 2016 Elsevier B.V. All rights reserved.

Prediction of Adsorption Equilibrium of VOCs onto Hyper-Cross-Linked Polymeric Resin at Environmentally Relevant Temperatures and Concentrations Using Inverse Gas Chromatography.

Science.gov (United States)

Jia, Lijuan; Ma, Jiakai; Shi, Qiuyi; Long, Chao

2017-01-03

Hyper-cross-linked polymeric resin (HPR) represents a class of predominantly microporous adsorbents and has good adsorption performance toward VOCs. However, adsorption equilibrium of VOCs onto HPR are limited. In this research, a novel method for predicting adsorption capacities of VOCs on HPR at environmentally relevant temperatures and concentrations using inverse gas chromatography data was proposed. Adsorption equilibrium of six VOCs (n-pentane, n-hexane, dichloromethane, acetone, benzene, 1, 2-dichloroethane) onto HPR in the temperature range of 403-443 K were measured by inverse gas chromatography (IGC). Adsorption capacities at environmentally relevant temperatures (293-328 K) and concentrations (P/P s = 0.1-0.7) were predicted using Dubinin-Radushkevich (DR) equation based on Polany's theory. Taking consideration of the swelling properties of HPR, the volume swelling ratio (r) was introduced and r·V micro was used instead of V micro determined by N 2 adsorption data at 77 K as the parameter q 0 (limiting micropore volume) of the DR equation. The results showed that the adsorption capacities of VOCs at environmentally relevant temperatures and concentrations can be predicted effectively using IGC data, the root-mean-square errors between the predicted and experimental data was below 9.63%. The results are meaningful because they allow accurate prediction of adsorption capacities of adsorbents more quickly and conveniently using IGC data.

[Effects of magnetron sputtered ZrN on the bonding strength of titanium porcelain].

Science.gov (United States)

Zhou, Shu; Zhang, Wen-yan; Guang, Han-bing; Xia, Yang; Zhang, Fei-min

2009-04-01

To investigate the effect of magnetron sputtered ZrN on the bonding strength between a low-fusing porcelain (Ti/Vita titankeramik system) and commercially pure cast titanium. Sixteen specimens were randomly assigned to test group and control group (n=8). The control group received no surface treated. Magnetron sputtered ZrN film was deposited on the surface of specimens in the test group. Then the sixteen titanium-porcelain specimens were prepared in a rectangular shape and went through three-point bending test on a universal test machine. The bond strength of Ti/porcelain was recorded. The phase composition of the specimens was analyzed using X-ray diffraction (XRD). The interface at titanium and porcelain and the titanium surface after debonding were observed with a scanning electron microscopy (SEM) and analyzed using energy depressive spectrum (EDS). New phase of ZrN was found with XRD in the test group. Statistical analysis showed higher bond strength following ZrN surface treatment in the test group [(45.991+/-0.648) MPa] than that in the control group [(29.483+/-1.007) MPa] (P=0.000). Bonded ceramic could be observed in test group, the amount of bonded ceramic was more than that in the control group. No obvious bonded ceramic in control group was found. Magnetron sputtered ZrN can improve bond strength of Ti/Vita titankeramik system significantly.

A study of the adsorption activities of silanol surface structures on a fused silica model substrate by combining 29Si CP MAS NMR and inverse gas chromatographic data

NARCIS (Netherlands)

Scholten, A.B.; Janssen, J.G.M.; Haan, de J.W.; Cramers, C.A.

1994-01-01

The possibilities of inverse gas-solid chromatog. (IGC) in obtaining chromatog. data on fumed silica were examd. Aerosil A-200, a fused silica model substrate in 29Si NMR anal., was trimethylsilylated to different degrees. IGC was used to vary reproducibly det. the free specific energies of

Improved genetic algorithms using inverse-elitism; Gyakuerito senryaku wo mochiita kairyo identeki algorithm

Energy Technology Data Exchange (ETDEWEB)

Kawanishi, H.; Hagiwara, M. [Keio University, Tokyo (Japan)

1998-05-01

Improved Genetic Algorithms (GAs) have been proposed in this paper. We have directed our attention to `selection` and `crossover` in GAs. Novel strategies in selection and crossover are used in the proposed method. Various selecting strategies have been used in the conventional GAs such as Elitism, Tournament, Ranking, Roulette wheel, and Expected value model. These are not always effective, since these refer to only the fitness of each chromosome. We have developed the following techniques to improve the conventional GAs: `inverse-elitism` as a selecting strategy and variable crossover range as a crossover strategy. In the `inverse-elitism`, an inverse-elite whose gene values are reversed from those in the corresponding elite is produced. This strategy greatly contributes to diversification of chromosomes. As for the variable crossover range, we combine the following crossover techniques effectively: one is that range in crossover is varied from wide to narrow gradually to carry out global search in the beginning and local search in the ending; another is that range in crossover is varied from narrow to wide. We confirmed validity and superior performance of the proposed method by computer simulations. 18 refs., 9 figs., 3 tabs.

Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

International Nuclear Information System (INIS)

Matyash, K; Froehlich, M; Kersten, H; Thieme, G; Schneider, R; Hannemann, M; Hippler, R

2004-01-01

During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed

Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

Energy Technology Data Exchange (ETDEWEB)

Matyash, K [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Froehlich, M [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Kersten, H [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Thieme, G [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Schneider, R [Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, 17489 Greifswald (Germany); Hannemann, M [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Hippler, R [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany)

2004-10-07

During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed.

Increase in the accuracy of approximating the profile of the erosion zone in planar magnetrons

Science.gov (United States)

Rogov, A. V.; Kapustin, Yu. V.

2017-09-01

It has been shown that the use of the survival function of the Weibull distribution shifted along the ordinate axis allows one to increase the accuracy of the approximation of the normalized profile of an erosion zone in the area from the axis to the maximum sputtering region compared with the previously suggested distribution function of the extremum values. The survival function of the Weibull distribution is used in the area from the maximum to the outer boundary of an erosion zone. The major advantage of using the new approximation is observed for magnetrons with a large central nonsputtered spot and for magnetrons with substantial sputtering in the paraxial zone.

Heated probe diagnostic inside of the gas aggregation nanocluster source

Science.gov (United States)

Kolpakova, Anna; Shelemin, Artem; Kousal, Jaroslav; Kudrna, Pavel; Tichy, Milan; Biederman, Hynek; Surface; Plasma Science Team

2016-09-01

Gas aggregation cluster sources (GAS) usually operate outside common working conditions of most magnetrons and the size of nanoparticles created in GAS is below that commonly studied in dusty plasmas. Therefore, experimental data obtained inside the GAS are important for better understanding of process of nanoparticles formation. In order to study the conditions inside the gas aggregation chamber, special ``diagnostic GAS'' has been constructed. It allows simultaneous monitoring (or spatial profiling) by means of optical emission spectroscopy, mass spectrometry and probe diagnostic. Data obtained from Langmuir and heated probes map the plasma parameters in two dimensions - radial and axial. Titanium has been studied as an example of metal for which the reactive gas in the chamber starts nanoparticles production. Three basic situations were investigated: sputtering from clean titanium target in argon, sputtering from partially pre-oxidized target and sputtering with oxygen introduced into the discharge. It was found that during formation of nanoparticles the plasma parameters differ strongly from the situation without nanoparticles. These experimental data will support the efforts of more realistic modeling of the process. Czech Science Foundation 15-00863S.

Adsorption isotherms of some alkyl aromatic hydrocarbons and surface energies on partially dealuminated Y faujasite zeolite by inverse gas chromatography.

Science.gov (United States)

Kondor, Anett; Dallos, András

2014-10-03

Adsorption isotherm data of some alkyl aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene) measured in the temperature range of 423-523K on a partially dealuminated faujasite type DAY F20 zeolite by inverse gas chromatography are presented in this work. The temperature dependent form of Tóth's equation has been fitted to the multiple temperature adsorption isotherms of benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene with standard deviations of 4.6, 5.0, 5.9, 4.3, 5.1 and 6.3mmolkg(-1) and coefficients of determinations (r(2)) of 0.977, 0.971, 0.974, 0.975, 0.991 and 0.991, respectively. The gas-solid equilibria and modeling were interpreted on the basis of the interfacial properties of the zeolite, by dispersive, specific and total surface energy heterogeneity profiles and distributions of the adsorbent measured by surface energy analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Properties of RF magnetron sputtered gallium nitride semiconductors doped with erbium

Czech Academy of Sciences Publication Activity Database

Peřina, Vratislav; Macková, Anna; Hnatowicz, Vladimír; Prajzler, V.; Machovič, V.; Matějka, P.; Schröfel, J.

2004-01-01

Roč. 36, č. 8 (2004), s. 952-954 ISSN 0142-2421 R&D Projects: GA ČR GA104/03/0387 Institutional research plan: CEZ:AV0Z1048901 Keywords : Er-doped GaN * luminescence * magnetron sputtering Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.209, year: 2004

SeisFlows-Flexible waveform inversion software

Science.gov (United States)

Modrak, Ryan T.; Borisov, Dmitry; Lefebvre, Matthieu; Tromp, Jeroen

2018-06-01

SeisFlows is an open source Python package that provides a customizable waveform inversion workflow and framework for research in oil and gas exploration, earthquake tomography, medical imaging, and other areas. New methods can be rapidly prototyped in SeisFlows by inheriting from default inversion or migration classes, and code can be tested on 2D examples before application to more expensive 3D problems. Wave simulations must be performed using an external software package such as SPECFEM3D. The ability to interface with external solvers lends flexibility, and the choice of SPECFEM3D as a default option provides optional GPU acceleration and other useful capabilities. Through support for massively parallel solvers and interfaces for high-performance computing (HPC) systems, inversions with thousands of seismic traces and billions of model parameters can be performed. So far, SeisFlows has run on clusters managed by the Department of Defense, Chevron Corp., Total S.A., Princeton University, and the University of Alaska, Fairbanks.

Multi-gas interaction modeling on decorated semiconductor interfaces: A novel Fermi distribution-based response isotherm and the inverse hard/soft acid/base concept

Energy Technology Data Exchange (ETDEWEB)

Laminack, William [Department of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Gole, James, E-mail: James.Gole@physics.gatech.edu [Department of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Department of Mechanical Engineering, Georgia Tech, Atlanta, GA 30332 (United States)

2015-12-30

Graphical abstract: Visual representation of the PS interface interacting with mixed gas configurations. The red dots correspond to nanostructured metal oxides. Each combination of distinct molecules are labeled below the pores, which are oversized in the figure. - Highlights: • First study of mixed gas analytes interacting with a micro-porous silicon substrate. • Responses are represented by a newly developed response absorption isotherm. • This isotherm is modeled on the basis of the Fermi distribution function. • The developing IHSAB concept explains multi-gas analyte–analyte interactions. - Abstract: A unique MEMS/NEMS approach is presented for the modeling of a detection platform for mixed gas interactions. Mixed gas analytes interact with nanostructured decorating metal oxide island sites supported on a microporous silicon substrate. The Inverse Hard/Soft acid/base (IHSAB) concept is used to assess a diversity of conductometric responses for mixed gas interactions as a function of these nanostructured metal oxides. The analyte conductometric responses are well represented using a combination diffusion/absorption-based model for multi-gas interactions where a newly developed response absorption isotherm, based on the Fermi distribution function is applied. A further coupling of this model with the IHSAB concept describes the considerations in modeling of multi-gas mixed analyte–interface, and analyte–analyte interactions. Taking into account the molecular electronic interaction of both the analytes with each other and an extrinsic semiconductor interface we demonstrate how the presence of one gas can enhance or diminish the reversible interaction of a second gas with the extrinsic semiconductor interface. These concepts demonstrate important considerations in the array-based formats for multi-gas sensing and its applications.

Stress Inversion of Coal with a Gas Drilling Borehole and the Law of Crack Propagation

Directory of Open Access Journals (Sweden)

Tianjun Zhang

2017-10-01

Full Text Available For studying the law of crack propagation around a gas drilling borehole, an experimental study about coal with a cavity under uniaxial compression was carried out, with the digital speckle correlation method capturing the images of coal failure. A sequence of coal failure images and the full-field strain of failure were obtained. The strain softening characteristic was shown by the curve. A method of curve dividing—named fitting-damaging—was proposed, combining the least square fitting residual norm and damage fraction. By this method, the five stages and four key points of a stress-strain curve were defined. Then, the full-field stress was inverted by means of the theory of elasticity and the adjacent element weight sharing model. The results show that σci was 30.28–41.71 percent of σf and σcd was 83.08–87.34 percent of σf, calculated by the fitting-damaging method, agreeing with former research. The results of stress inversion showed that under a low stress level (0.15 σf < σ < 0.5 σf, microdamage evolving into plastic failure later was formed around the cavity. Under a high stress level (0.5 σf < σ < 0.85 σf, the region of stress concentration suddenly crazed and formed a brittle crack. When σ ≥ 0.85 σf, the crack was developing, crack lines were connecting with each other, and the coal finally failed. The outcome of the stress inversion was completely concomitant with the images of crack propagation. Additionally, the stress around the cavity was able to be calculated accurately.

Thickness characteristics of YBaCuO system thin films prepared by RF magnetron sputtering

International Nuclear Information System (INIS)

Furuhashi, Hideo; Jinno, Makoto; Takashima, Osamu; Uchida, Yoshiyuki; Maeda, Akinori; Kojima, Kenzo; Ochiai, Shizuyasu; Ohashi, Asao

1994-01-01

The practical use of oxide high temperature superconductors for electronics field has been advanced. The oxide high temperature superconductor thin films is very sensitive to the production conditions, and their making with good reproducibility is difficult. In this study, the method of producing the thin films having good quality with good reproducibility by RF magnetron sputtering, and the relation of the film thickness with the superconductivity characteristics of YBaCuO system thin films in the different methods of substrate washing were examined. The sputtering conditions are shown. For the purpose of preventing the worsening of the film quality due to the reverse sputtering of oxygen negative ions to the thin film surface, sputtering gas pressure was set up high at 30 Pa. The film thickness and the temperature-resistance characteristics were measured. The experimental method and the experimental results are reported. By keeping the temperature on substrate surfaces constant, the reproducibility in the production of the thin films was improved remarkably. The effect of substrate washing was large. (K.I.)

CrN thin films prepared by reactive DC magnetron sputtering for symmetric supercapacitors

KAUST Repository

Wei, Binbin; Liang, Hanfeng; Zhang, Dongfang; Wu, Zhengtao; Qi, Zhengbing; Wang, Zhoucheng

2016-01-01

stability are promising candidates as supercapacitor electrode materials. In this work, we report the fabrication of CrN thin films using reactive DC magnetron sputtering and further their applications for symmetric supercapacitors for the first time. The Cr

Comparative analysis of electrophysical properties of ceramic tantalum pentoxide coatings, deposited by electron beam evaporation and magnetron sputtering methods

Science.gov (United States)

Donkov, N.; Mateev, E.; Safonov, V.; Zykova, A.; Yakovin, S.; Kolesnikov, D.; Sudzhanskaya, I.; Goncharov, I.; Georgieva, V.

2014-12-01

Ta2O5 ceramic coatings have been deposited on glass substrates by e-beam evaporation and magnetron sputtering methods. For the magnetron sputtering process Ta target was used. X-ray diffraction measurements show that these coatings are amorphous. XPS survey spectra of the ceramic Ta2O5 coatings were obtained. All spectra consist of well-defined XPS lines of Ta 4f, 4d, 4p and 4s; O 1s; C 1s. Ta 4f doublets are typical for Ta2O5 coatings with two main peaks. Scanning electron microscopy and atomic force microscopy images of the e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have revealed a relatively flat surface with no cracks. The dielectric properties of the tantalum pentoxide coatings have been investigated in the frequency range of 100 Hz to 1 MHz. The electrical behaviour of e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have also been compared. The deposition process conditions principally effect the structure parameters and electrical properties of Ta2O5 ceramic coatings. The coatings deposited by different methods demonstrate the range of dielectric parameters due to the structural and stoichiometric composition changes

Pd-catalysts for DFAFC prepared by magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Bieloshapka, Igor; Jiříček, Petr; Vorokhta, M.; Tomšík, Elena; Rednyk, A.; Perekrestov, R.; Jurek, Karel; Ukraintsev, Egor; Hruška, Karel; Romanyuk, Olexandr; Lesiak, B.

2017-01-01

Roč. 419, Oct (2017), s. 838-846 ISSN 0169-4332 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015088 Institutional support: RVO:68378271 ; RVO:61389013 Keywords : Pd catalyst * formic acid fuel cell * magnetron sputtering * DFAFC * surface morphology Subject RIV: BM - Solid Matter Physics ; Magnetism; BM - Solid Matter Physics ; Magnetism (UMCH-V) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Condensed matter physics (including formerly solid state physics, supercond.) (UMCH-V) Impact factor: 3.387, year: 2016

Magnetron sputtering system with an annual discharge zone and two cathode modules

International Nuclear Information System (INIS)

Savich, V. A.; Yasyunas, A. A.; Kovrigo, V. M.; Kotov, D. A.; Shiripov, V. Ya.

2013-01-01

In this article, general discharge characteristics of a cylindrical magnetron sputtering system with an annual sputtering zone and a high target usage coefficient designed for transparent conducting coatings are shown. Two coupled DC-cathodes are used to improve coating uniformity. Radial sputtered material fluxes are being created. The engineered magnetic system is extremely balanced (G-factor is much higher than 2) and thus provides maximal effective operating power higher than 6 kW. The effectiveness of a magnetic trap results in a fast work cycle (less than 1.5 min) and a high target material usage coefficient (higher than 40%). A multipole magnetic field with null magnetic flux density zones lower target’s surface is being created. There is an influence between cathode modules despite mutual magnetic isolation, so magnetic conductors-shunts are used to weaken it. The magnetron can be used to sputter both metals and conducting ceramics (including ITO). (authors)

Contribution to crystallographical and mechanical analysis of molybdenum coatings prepared by magnetron cathode sputtering

International Nuclear Information System (INIS)

Bosland, P.

1989-07-01

Molybdenum coatings with different compression stresses are obtained by magnetron cathode sputtering by varying negative voltage applied to the substrate during deposition. Stress evolution, crystal texture and argon content are studied [fr

Use of Genetic Algorithms to solve Inverse Problems in Relativistic Hydrodynamics

Science.gov (United States)

Guzmán, F. S.; González, J. A.

2018-04-01

We present the use of Genetic Algorithms (GAs) as a strategy to solve inverse problems associated with models of relativistic hydrodynamics. The signal we consider to emulate an observation is the density of a relativistic gas, measured at a point where a shock is traveling. This shock is generated numerically out of a Riemann problem with mildly relativistic conditions. The inverse problem we propose is the prediction of the initial conditions of density, velocity and pressure of the Riemann problem that gave origin to that signal. For this we use the density, velocity and pressure of the gas at both sides of the discontinuity, as the six genes of an organism, initially with random values within a tolerance. We then prepare an initial population of N of these organisms and evolve them using methods based on GAs. In the end, the organism with the best fitness of each generation is compared to the signal and the process ends when the set of initial conditions of the organisms of a later generation fit the Signal within a tolerance.

RF magnetron sputtering and evaporation of polyisobutylene and low density polyethylene

Czech Academy of Sciences Publication Activity Database

Kousal, J.; Hanuš, J.; Choukourov, A.; Hlídek, P.; Biederman, H.; Slavinská, D.; Zemek, Josef

2005-01-01

Roč. 200, 1-4 (2005), s. 472-475 ISSN 0257-8972 R&D Projects: GA MŠk(CZ) OC 527.10; GA MŠk(CZ) ME 553 Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetron * radio frequency * sputtering * polyethylene * polyisobutylene Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.646, year: 2005

Advanced TiC/a-C : H nanocomposite coatings deposited by magnetron sputtering

NARCIS (Netherlands)

Pei, Y.T.; Galvan, D.; Hosson, J.Th.M. De; Strondl, C.

2006-01-01

TiC/a-C:H nanocomposite coatings have been deposited by magnetron Sputtering. They consist of 2-5 nm TiC nanocrystallites embedded in the amorphous hydrocarbon (a-C:H) matrix. A transition from a Columnar to a glassy microstructure has been observed in the nanocomposite coatings with increasing

[Effect of niobium nitride on the bonding strength of titanium porcelain by magnetron sputtering].

Science.gov (United States)

Wang, Shu-shu; Zhang, La-bao; Guang, Han-bing; Zhou, Shu; Zhang, Fei-min

2010-05-01

To investigate the effect of magnetron sputtered niobium nitride (NbN) on the bonding strength of commercially pure cast titanium (Ti) and low-fusing porcelain (Ti/Vita titankeramik system). Sixty Ti specimens were randomly divided into four groups, group T1, T2, T3 and T4. All specimens of group T1 and T2 were first treated with 120 microm blasted Al2O3 particles, and then only specimens of group T2 were treated with magnetron sputtered NbN film. All specimens of group T3 and T4 were first treated with magnetron sputtered NbN film and then only specimens of group T4 were treated with 120 microm blasted Al2O3 particles. The composition of the deposits were analyzed by X-ray diffraction (XRD). A universal testing machine was used to perform the three-point bending test to evaluate the bonding strength of Ti and porcelain. The microstructure of NbN, the interface of Ti-porcelain and the fractured Ti surface were observed with scanning electron microscopy (SEM) and energy depressive spectrum (EDS), and the results were compared. The XRD results showed that the NbN deposits were cubic crystalline phases. The bonding strength of Ti and porcelain in T1 to T4 group were (27.2+/-0.8), (43.1+/-0.6), (31.4+/-1.0) and (44.9+/-0.6) MPa. These results were analyzed by one-way analysis of variance and differences between groups were compared using least significant difference test. Significant inter-group differences were found among all groups (Pporcelain, while samples treated with both Al2O3 and NbN had better bond. EDS of Ti-porcelain interface showed oxidation occurred in T1, T2 and T3, but was well controlled in T4. Magnetron sputtered NbN can prevent Ti from being oxidized, and can improve the bonding strength of Ti/Vita titankeramik system. Al2O3 blast can also improve the bonding strength of Ti/Vita titankeramik system.

Radio-frequency magnetron sputtering and wet thermal oxidation of ZnO thin film

International Nuclear Information System (INIS)

Liu, H. F.; Chua, S. J.; Hu, G. X.; Gong, H.; Xiang, N.

2007-01-01

The authors studied the growth and wet thermal oxidation (WTO) of ZnO thin films using a radio-frequency magnetron sputtering technique. X-ray diffraction reveals a preferred orientation of [1010]ZnO(0002)//[1120]Al 2 O 3 (0002) coexisted with a small amount of ZnO (1011) and ZnO (1013) crystals on the Al 2 O 3 (0001) substrate. The ZnO (1011) and ZnO (1013) crystals, as well as the in-plane preferred orientation, are absent from the growth of ZnO on the GaAs(001) substrate. WTO at 550 deg. C improves the crystalline and the photoluminescence more significantly than annealing in air, N 2 and O 2 ambient; it also tends to convert the crystal from ZnO (1011) and ZnO (1013) to ZnO (0002). The evolution of the photoluminescence upon WTO and annealing reveals that the green and orange emissions, centered at 520 and 650 nm, are likely originated from oxygen vacancies and oxygen interstitials, respectively; while the 420 nm emission, which is very sensitive to the postgrowth thermal processing regardless of the substrate and the ambient gas, is likely originated from the surface-state related defects

Inverse gas chromatography as a method for determination of surface properties of binding materials

Science.gov (United States)

Yu, Jihai; Lu, Xiaolei; Yang, Chunxia; Du, Baoli; Wang, Shuxian; Ye, Zhengmao

2017-09-01

Inverse gas chromatography (IGC) is a promising measurement technique for investigating the surface properties of binding materials, which are the major influence element for the adsorption performance of superplasticizer. In this work, using the IGC method, blast furnace slag (BFS), sulphoaluminate cement (SAC) and portland cement (P·O) are employed to systematically evaluate the corresponding dispersive component (γsd), specific surface free energy (γsab), and acid-base properties. The obtained results show that γsd contributes to a major section of the surface free energy in the three binding materials, suggesting they are of a relatively low polarity. Compared to the two kinds of cements, the BFS possesses the highest dispersive and specific surface free energies (the values are 45.01 mJ/m2 and 11.68 mJ/m2, respectively), and also exhibits a wider distribution range of γsd, indicating their surfaces are heterogeneous. For acid-base properties, the results indicate the surfaces of three samples are basic in nature. In addition, the adsorption investigation shows that per unit surface of BFS adsorbs the most superplasticizer molecules, which indicates the higher surface free energies is beneficial to the superplasticizer adsorption.

Heat treatable indium tin oxide films deposited with high power pulse magnetron sputtering

International Nuclear Information System (INIS)

Horstmann, F.; Sittinger, V.; Szyszka, B.

2009-01-01

In this study, indium tin oxide (ITO) films were prepared by high power pulse magnetron sputtering [D. J. Christie, F. Tomasel, W. D. Sproul, D. C. Carter, J. Vac. Sci. Technol. A, 22 (2004) 1415. ] without substrate heating. The ITO films were deposited from a ceramic target at a deposition rate of approx. 5.5 nm*m/min kW. Afterwards, the ITO films were covered with a siliconoxynitride film sputtered from a silicon alloy target in order to prevent oxidation of the ITO film during annealing at 650 deg. C for 10 min in air. The optical and electrical properties as well as the texture and morphology of these films were investigated before and after annealing. Mechanical durability of the annealed films was evaluated at different test conditions. The results were compared with state-of-the art ITO films which were obtained at optimized direct current magnetron sputtering conditions

The microstructure and properties of titanium dioxide films synthesized by unbalanced magnetron sputtering

International Nuclear Information System (INIS)

Leng, Y.X.; Chen, J.Y.; Yang, P.; Sun, H.; Huang, N.

2007-01-01

In this work, titanium oxide films were deposited on Ti6Al4V and Si (1 0 0) by DC unbalanced magnetron sputtering method at different oxygen pressure. X-ray diffraction (XRD), microhardness tests, pin-on-disk wear experiments, surface contact angle tests and platelet adhesion investigation were conducted to evaluate the properties of the films. The corrosion behavior of titanium dioxide films was characterized by potentiodynamic polarization. The results showed that titanium oxide films deposited by unbalance magnetron sputtering were compact and could obviously enhance microhardness, wear resistance of titanium alloy substrate. Potentiodynamic polarization curves showed that Ti-6Al-4V deposited with titanium dioxide films had lower dissolution currents than that of the uncoated one. The results of in vitro hemocompatibility analyses indicated that the blood compatibility of the titanium dioxide films with bandgap 3.2 eV have better blood compatibility

Determination of thermodynamic properties of poly(cyclohexyl methacrylate)by inverse gas chromatography

Institute of Scientific and Technical Information of China (English)

Ismet KAYA; Cigdem Yigit PALA

2014-01-01

In this work,some thermodynamic properties of poly( cyclohexyl methacrylate)were studied by inverse gas chromatography( IGC). For this purpose,the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times(tr)of the probes were determined from the interactions of poly(cyclohexyl methacrylate)with n-pentane,n-hexane,n-heptane,n-octane,n-decane, methanol,ethanol,2-propanol,butanol,acetone,ethyl methyl ketone,benzene,toluene and o-xylene by IGC technique. Then,the specific volume(V0g)was determined for each probe molecule. By using(1/T;lnV0g) graphics,the glass transition temperature of poly( cyclohexyl methacrylate)was found to be 373 K. The adsorp-tion heat under the glass transition temperature(ΔH a ),and partial molar heat of sorption above the glass tran-sition(ΔHS1 ),partial molar free energy of sorption(ΔGS1 )and partial molar entropy of sorption(ΔSS1 )belong-ing to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution(ΔH∞1 ), partial molar free energy of mixing at infinite dilution(ΔG∞1 ),Flory-Huggins interaction parameter(χ∞12 )and weight fraction activity coefficient(a1/w1)∞ values of polymer-solute systems were calculated at different col-umn temperatures. The solubility parameters(δ2 )of the polymer were obtained by IGC technique.

Determination of thermodynamic properties of poly (cyclohexyl methacrylate) by inverse gas chromatography.

Science.gov (United States)

Kaya, Ismet; Pala, Cigdem Yigit

2014-07-01

In this work, some thermodynamic properties of poly (cyclohexyl methacrylate) were studied by inverse gas chromatography (IGC). For this purpose, the polymeric substance was coated on Chromosorb W and which was filled into a glass column. The retention times (t(r)) of the probes were determined from the interactions of poly (cyclohexyl methacrylate) with n-pentane, n-hexane, n-heptane, n-octane, n-decane, methanol, ethanol, 2-propanol, butanol, acetone, ethyl methyl ketone, benzene, toluene and o-xylene by IGC technique. Then, the specific volume (Vg(0)) was determined for each probe molecule. By using (1/T; lnVg(0)) graphics, the glass transition temperature of poly (cyclohexyl methacrylate) was found to be 373 K. The adsorption heat under the glass transition temperature (deltaH(a)), and partial molar heat of sorption above the glass transition (deltaH1(S)), partial molar free energy of sorption (deltaG1(S)) and partial molar entropy of sorption (deltaS1(S)) belonging to sorption for every probe were calculated. The partial molar heat of mixing at infinite dilution (deltaH1(infinity)), partial molar free energy of mixing at infinite dilution (deltaG1(infinity)), Flory-Huggins interaction parameter (chi12(infinity)) and weight fraction activity coefficient (a1/w1)(infinity) values of polymer-solute systems were calculated at different column temperatures. The solubility parameters (delta2) of the polymer were obtained by IGC technique.

Determination of the Thermodynamic Properties of Poly [2-(3-phenyl-3-methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] at Infinite Dilution by Inverse Gas Chromatography

OpenAIRE

KAYA, İsmet

2014-01-01

Some thermodynamic quantities were obtained for the interactions of poly [2-(3-phenyl -3- methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] Poly (PCHEMA-co-MA) with alcohols, ketones, acetates, aromatics and n-alkanes by inverse gas chromatography in the temperature range of 150-180oC. The specific retention volumes, Vgo, weight fraction activity coefficients of solute probes at infinite dilution, W1\\infty and Flory-Huggins thermodynamic interaction parameters, c12...

Semiconductor inversion contact - a new heterogeneous structure with two-dimensional zero-mass electron gas

International Nuclear Information System (INIS)

Volkov, B.A.; Pankratov, O.A.

1986-01-01

Semiconductor inversion junction, presenting the contact of materials in which energy levels corresponding to band edges are mutually inverted. At that, the symmetry of wave function of conductivity band in one material coincides with the symmetry of valence band of the other and vice versa. Specificity of the inversion contact is determined by the presence of electron states independent of the transition band type, which are similar to soliton ones in one-dimensional systems. In the region of the junction the states are characterized by linear massless spectrum nondegenerate in spin. Energy spectrum of the inversion junction for semiconductors of the Pb 1-x Sn y Te x type is considered

Development of thin film cathodes for lithium-ion batteries in the material system Li–Mn–O by r.f. magnetron sputtering

International Nuclear Information System (INIS)

Fischer, J.; Adelhelm, C.; Bergfeldt, T.; Chang, K.; Ziebert, C.; Leiste, H.; Stüber, M.; Ulrich, S.; Music, D.; Hallstedt, B.; Seifert, H.J.

2013-01-01

Today most commercially available lithium ion batteries are still based on the toxic and expensive LiCoO 2 as a standard cathode material. However, lithium manganese based cathode materials are cheaper and environmentally friendlier. In this work cubic-LiMn 2 O 4 spinel, monoclinic-Li 2 MnO 3 and orthorhombic-LiMnO 2 thin films have been synthesized by non-reactive r.f. magnetron sputtering from two ceramic targets (LiMn 2 O 4 , LiMnO 2 ) in a pure argon discharge. The deposition parameters, namely target power and working gas pressure, were optimized in a combination with a post deposition heat treatment with respect to microstructure and electrochemical behavior. The chemical composition was determined using inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The films' crystal structure, phase evolution and morphology were investigated by X-ray diffraction, micro Raman spectroscopy and scanning electron microscopy. Due to the fact that these thin films consist of the pure active material without any impurities, such as binders or conductive additives like carbon black, they are particularly well suited for measurements of the intrinsic physical properties, which is essential for fundamental understanding. The electrochemical behavior of the cubic and the orthorhombic films was investigated by galvanostatic cycling in half cells against metallic lithium. The cubic spinel films exhibit a maximum specific capacity of ∼ 82 mAh/g, while a specific capacity of nearly 150 mAh/g can be reached for the orthorhombic counterparts. These films are promising candidates for future all solid state battery applications. - Highlights: ► Synthesis of 3 Li–Mn–O structures by one up-scalable thin film deposition method ► Formation of o-LiMnO 2 by r.f. magnetron sputtering in combination with post-annealing ► Discharge capacity with o-LiMnO 2 cathodes twice as high as for c-LiMn 2 O 4 ► Thin film deposition of m-Li 2 MnO 3 and

Novel high power impulse magnetron sputtering enhanced by an auxiliary electrical field

Energy Technology Data Exchange (ETDEWEB)

Li, Chunwei, E-mail: lcwnefu@126.com, E-mail: xiubotian@163.com [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Tian, Xiubo, E-mail: lcwnefu@126.com, E-mail: xiubotian@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

2016-08-15

The high power impulse magnetron sputtering (HIPIMS) technique is a novel highly ionized physical vapor deposition method with a high application potential. However, the electron utilization efficiency during sputtering is rather low and the metal particle ionization rate needs to be considerably improved to allow for a large-scale industrial application. Therefore, we enhanced the HIPIMS technique by simultaneously applying an electric field (EF-HIPIMS). The effect of the electric field on the discharge process was studied using a current sensor and an optical emission spectrometer. Furthermore, the spatial distribution of the electric potential and electric field during the EF-HIPIMS process was simulated using the ANSYS software. The results indicate that a higher electron utilization efficiency and a higher particle ionization rate could be achieved. The auxiliary anode obviously changed the distribution of the electric potential and the electric field in the discharge region, which increased the plasma density and enhanced the degree of ionization of the vanadium and argon gas. Vanadium films were deposited to further compare both techniques, and the morphology of the prepared films was investigated by scanning electron microscopy. The films showed a smaller crystal grain size and a denser growth structure when the electric field was applied during the discharge process.

Heteroepitaxial Ge-on-Si by DC magnetron sputtering

Directory of Open Access Journals (Sweden)

Martin Steglich

2013-07-01

Full Text Available The growth of Ge on Si(100 by DC Magnetron Sputtering at various temperatures is studied by Spectroscopic Ellipsometry and Transmission Electron Microscopy. Smooth heteroepitaxial Ge films are prepared at relatively low temperatures of 380°C. Typical Stransky-Krastanov growth is observed at 410°C. At lower temperatures (320°C, films are essentially amorphous with isolated nanocrystallites at the Si-Ge interface. A minor oxygen contamination at the interface, developing after ex-situ oxide removal, is not seen to hinder epitaxy. Compensation of dislocation-induced acceptors in Ge by sputtering from n-doped targets is proposed.

Combined optical emission and resonant absorption diagnostics of an Ar-O{sub 2}-Ce-reactive magnetron sputtering discharge

Energy Technology Data Exchange (ETDEWEB)

El Mel, A.A. [Chimie des Interactions Plasma-Surface (ChIPS), Research Institute for Materials Science and Engineering, Université de Mons, Place du Parc 23, Mons B-7000 (Belgium); Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, 2 rue de la Houssinière B.P. 32229, Nantes Cedex 3 44322 (France); Ershov, S. [Chimie des Interactions Plasma-Surface (ChIPS), Research Institute for Materials Science and Engineering, Université de Mons, Place du Parc 23, Mons B-7000 (Belgium); Britun, N., E-mail: nikolay.britun@umons.ac.be [Chimie des Interactions Plasma-Surface (ChIPS), Research Institute for Materials Science and Engineering, Université de Mons, Place du Parc 23, Mons B-7000 (Belgium); Ricard, A. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, Toulouse Cedex 9 F-31062 (France); Konstantinidis, S. [Chimie des Interactions Plasma-Surface (ChIPS), Research Institute for Materials Science and Engineering, Université de Mons, Place du Parc 23, Mons B-7000 (Belgium); Snyders, R. [Chimie des Interactions Plasma-Surface (ChIPS), Research Institute for Materials Science and Engineering, Université de Mons, Place du Parc 23, Mons B-7000 (Belgium); Materia Nova Research Center, Parc Initialis, Avenue Copernic 1, Mons B-7000 (Belgium)

2015-01-01

We report the results on combined optical characterization of Ar-O{sub 2}-Ce magnetron sputtering discharges by optical emission and resonant absorption spectroscopy. In this study, a DC magnetron sputtering system equipped with a movable planar magnetron source with a Ce target is used. The intensities of Ar, O, and Ce emission lines, as well as the absolute densities of Ar metastable and Ce ground state atoms are analyzed as a function of the distance from the magnetron target, applied DC power, O{sub 2} content, etc. The absolute number density of the Ar{sup m} is found to decrease exponentially as a function of the target-to-substrate distance. The rate of this decrease is dependent on the sputtering regime, which should be due to the different collisional quenching rates of Ar{sup m} by O{sub 2} molecules at different oxygen contents. Quantitatively, the absolute number density of Ar{sup m} is found to be equal to ≈ 3 × 10{sup 8} cm{sup −3} in the metallic, and ≈ 5 × 10{sup 7} cm{sup −3} in the oxidized regime of sputtering, whereas Ce ground state densities at the similar conditions are found to be few times lower. The absolute densities of species are consistent with the corresponding deposition rates, which decrease sharply during the transition from metallic to poisoned sputtering regime. - Highlights: • Optical emission and resonant absorption spectroscopy are employed to study Ar-O{sub 2}-Ce magnetron sputtering discharges. • The density of argon metastables is found to decrease exponentially when increasing the target-to-substrate distance. • The collision-quenching rates of Ar{sup m} by O{sub 2} molecules at different oxygen contents is demonstrated. • The deposition rates of cerium and cerium oxide thin films decrease sharply during the transition from the metallic to the poisoned sputtering regime.

Inverse Estimation of Surface Radiation Properties Using Repulsive Particle Swarm Optimization Algorithm

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyun Ho [Sejong University, Sejong (Korea, Republic of); Kim, Ki Wan [Agency for Defense Development, Daejeon (Korea, Republic of)

2014-09-15

The heat transfer mechanism for radiation is directly related to the emission of photons and electromagnetic waves. Depending on the participation of the medium, the radiation can be classified into two forms: surface and gas radiation. In the present study, unknown radiation properties were estimated using an inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure. For efficiency, a repulsive particle swarm optimization (RPSO) algorithm, which is a relatively recent heuristic search method, was used as inverse solver. By comparing the convergence rates and accuracies with the results of a genetic algorithm (GA), the performances of the proposed RPSO algorithm as an inverse solver was verified when applied to the inverse analysis of the surface radiation problem.

Inverse Estimation of Surface Radiation Properties Using Repulsive Particle Swarm Optimization Algorithm

International Nuclear Information System (INIS)

Lee, Kyun Ho; Kim, Ki Wan

2014-01-01

The heat transfer mechanism for radiation is directly related to the emission of photons and electromagnetic waves. Depending on the participation of the medium, the radiation can be classified into two forms: surface and gas radiation. In the present study, unknown radiation properties were estimated using an inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure. For efficiency, a repulsive particle swarm optimization (RPSO) algorithm, which is a relatively recent heuristic search method, was used as inverse solver. By comparing the convergence rates and accuracies with the results of a genetic algorithm (GA), the performances of the proposed RPSO algorithm as an inverse solver was verified when applied to the inverse analysis of the surface radiation problem

Stationary Population Inversion in an Expanding Argon Plasma Jet by Helium Puffing

National Research Council Canada - National Science Library

Akatsuka, H; Kano, K

2005-01-01

... out. Population inversion between Ar I excited states 5s'->4p'[1/2]1 and 5s'->4p[3/2]1,2, [5/2]2,3 is created by helium gas-contact cooling of electrons, whereas it is not created without gas-contact. Ar I lines 1.14 m, 1.34 m...

Preparation and Characterization of FC Films Coated on PET Substrates by RF Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Huang Mei-lin

2018-01-01

Full Text Available Fluorocarbon (FC films were prepared on polyethylene terephthalate (PET plates and PET fabrics respectively by a radiofrequency (RF magnetron sputtering technique using polytetrafluoroethylene (PTFE as a target. Scanning electron microscope and X-ray photoelectron spectroscopy were used to investigate the morphology, structure and composition of the obtained FC films. The hydrophobicity and uvioresistant properties of the FC film coated fabric were studied. The results show that the FC films were successfully deposited on the PET substrates by a RF magnetron sputtering. The deposited films are made up of four components -CF3, -CF2-, CF- and -C-. The proportions of the four components and surface morphologies of the deposited films vary with the sputtering conditions. Compared with the original fabric samples, the hydrophobicity of the FC film coated fabrics is quite good and improved significantly.

High-speed deposition of protective films of aluminium oxide by the method of reactive magnetron sputtering

International Nuclear Information System (INIS)

Bugaev, S.P.; Zakhrov, A.N.; Ladyzhenskii, O.P.; Sochugov, M.S.

2001-01-01

The high optical characteristics of aluminium films made them attractive for different functional and decorative applications. It is well-known that the corrosion resistance of alloying is determined by the presence of the oxide film on its surface, but on the aluminium films, deposited by vacuum methods, the resistance is extremely low resulting in the relatively rapid failure of the coating. At present, there is a large number of methods of depositing the films of aluminium oxide. In most cases, it is recommended to use reactive magnetron sputtering of an aluminium target in a magnetron spraying system (MSS) using direct current, on dispersion of the target of aluminium oxide in a high-frequency MSS

Nanostructured multilayers of TiN/ZrN obtained by magnetron sputtering

International Nuclear Information System (INIS)

Caicedo A, J.C.; Bejarano G, G.; Gomez, M.E.; Prieto, P.; Cortez, C.; Munoz, J.

2007-01-01

In order to find an industrial application for thin films of TiN and ZrN monolayers, as well as TiN/ZrN multilayers were deposited onto silicon (100) and AISI 5160 steel substrates by r.f. (13.56 MHz) multi-target magnetron sputtering from high-purity (99.5%) Ti and (99.5%) Zr targets in an Ar (93%)/N 2 (7%) gas mixture. For their deposition, we applied a substrate bias voltage of -100 V and a target power of 350 W. The films were deposited at a pressure of 6x10 -3 mbar and a temperature of 250 C. The structure, composition, morphology, and topography were characterized by, XRD, FTIR, SEM, AFM, and optical microscopy. Mechanical properties like hardness and elastic modulus were determined by Nanoindentation. Hardness and elastic modulus of the films increased proportionally to the number of bilayers. Finally, cutting tools were coated with 1, 2, 3, 4, 5, 6, 7, and 8 bilayers of TiN/ZrN. Cutting tests on paper blades were conducted. Increased cut quality performance was observed for cutting tools coated with 8 bilayers, as compared to uncoated tools. This work opens the possibility to use coated AISI 5160 as cutting tools for the paper industry, reducing the import of expensive high-quality tool steel. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Nanostructured multilayers of TiN/ZrN obtained by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Caicedo A., J.C. [CDT ASTIN, SENA Regional Valle, Cali (Colombia); Grupo de Peliculas Delgadas, Universidad del Valle (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Bejarano G., G. [CDT ASTIN, SENA Regional Valle, Cali (Colombia); Group of Corrosion and Protection, Antioquia University, Medellin (Colombia); Gomez, M.E. [Grupo de Peliculas Delgadas, Universidad del Valle (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Prieto, P. [Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Cortez, C.; Munoz, J. [Centro de Investigacion y Estudios Avanzados del CINVESTAV-IPN, Queretaro (Mexico)

2007-07-01

In order to find an industrial application for thin films of TiN and ZrN monolayers, as well as TiN/ZrN multilayers were deposited onto silicon (100) and AISI 5160 steel substrates by r.f. (13.56 MHz) multi-target magnetron sputtering from high-purity (99.5%) Ti and (99.5%) Zr targets in an Ar (93%)/N{sub 2} (7%) gas mixture. For their deposition, we applied a substrate bias voltage of -100 V and a target power of 350 W. The films were deposited at a pressure of 6x10{sup -3} mbar and a temperature of 250 C. The structure, composition, morphology, and topography were characterized by, XRD, FTIR, SEM, AFM, and optical microscopy. Mechanical properties like hardness and elastic modulus were determined by Nanoindentation. Hardness and elastic modulus of the films increased proportionally to the number of bilayers. Finally, cutting tools were coated with 1, 2, 3, 4, 5, 6, 7, and 8 bilayers of TiN/ZrN. Cutting tests on paper blades were conducted. Increased cut quality performance was observed for cutting tools coated with 8 bilayers, as compared to uncoated tools. This work opens the possibility to use coated AISI 5160 as cutting tools for the paper industry, reducing the import of expensive high-quality tool steel. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

A novel DC Magnetron sputtering facility for space research and synchrotron radiation optics

DEFF Research Database (Denmark)

Hussain, A.M.; Christensen, Finn Erland; Pareschi, G.

1998-01-01

A new DC magnetron sputtering facility has been build up at the Danish Space Research Institute (DSRI), specially designed to enable uniform coatings of large area curved optics, such as Wolter-I mirror optics used in space telescopes and curved optics used in synchrotron radiation facilities...

Inverse Faraday effect with plasmon beams

International Nuclear Information System (INIS)

Ali, S; Mendonca, J T

2011-01-01

The angular momentum conservation equation is considered for an electron gas, in the presence of Laguerre-Gaussian (LG) plasmons propagating along the z-axis. The LG plasmons carry a finite orbital angular momentum despite longitudinal nature, which can be partly transfered to the electrons. For short timescales, such that ion motion can be neglected, plasmons primarily interact with the electrons, creating an azimuthal electric field and generating an axial magnetic field. This effect can be called an inverse Faraday effect due to plasmons. Numerically, it is found that the magnitude of the magnetic field enhances with the plasmon density or with the energy of the electron plasma waves. A comparison of the magnitudes of the axial magnetic field is made for the inverse Faraday effect excited by both plasmons and transverse photons.

Heating of polymer substrate by discharge plasma in radiofrequency magnetron sputtering deposition

International Nuclear Information System (INIS)

Sirghi, Lucel; Popa, Gheorghe; Hatanaka, Yoshinori

2006-01-01

The substrate used for the thin film deposition in a radiofrequency magnetron sputtering deposition system is heated by the deposition plasma. This may change drastically the surface properties of the polymer substrates. Deposition of titanium dioxide thin films on polymethyl methacrylate and polycarbonate substrates resulted in buckling of the substrate surfaces. This effect was evaluated by analysis of atomic force microscopy topography images of the deposited films. The amount of energy received by the substrate surface during the film deposition was determined by a thermal probe. Then, the results of the thermal probe measurements were used to compute the surface temperature of the polymer substrate. The computation revealed that the substrate surface temperature depends on the substrate thickness, discharge power and substrate holder temperature. For the case of the TiO 2 film depositions in the radiofrequency magnetron plasma, the computation indicated substrate surface temperature values under the polymer melting temperature. Therefore, the buckling of polymer substrate surface in the deposition plasma may not be regarded as a temperature driven surface instability, but more as an effect of argon ion bombardment

Understanding deposition rate loss in high power impulse magnetron sputtering: I. Ionization-driven electric fields

International Nuclear Information System (INIS)

Brenning, N; Huo, C; Raadu, M A; Lundin, D; Helmersson, U; Vitelaru, C; Stancu, G D; Minea, T

2012-01-01

The lower deposition rate for high power impulse magnetron sputtering (HiPIMS) compared with direct current magnetron sputtering for the same average power is often reported as a drawback. The often invoked reason is back-attraction of ionized sputtered material to the target due to a substantial negative potential profile, sometimes called an extended presheath, from the location of ionization toward the cathode. Recent studies in HiPIMS devices, using floating-emitting and swept-Langmuir probes, show that such extended potential profiles do exist, and that the electric fields E z directed toward the target can be strong enough to seriously reduce ion transport to the substrate. However, they also show that the potential drops involved can vary by up to an order of magnitude from case to case. There is a clear need to understand the underlying mechanisms and identify the key discharge variables that can be used for minimizing the back-attraction. We here present a combined theoretical and experimental analysis of the problem of electric fields E z in the ionization region part of HiPIMS discharges, and their effect on the transport of ionized sputtered material. In particular, we have investigated the possibility of a ‘sweet spot’ in parameter space in which the back-attraction of ionized sputtered material is low. It is concluded that a sweet spot might possibly exist for some carefully optimized discharges, but probably in a rather narrow window of parameters. As a measure of how far a discharge is from such a window, a Townsend product Π Townsend is proposed. A parametric analysis of Π Townsend shows that the search for a sweet spot is complicated by the fact that contradictory demands appear for several of the externally controllable parameters such as high/low working gas pressure, short/long pulse length, high/low pulse power and high/low magnetic field strength. (paper)

Test stand for magnetron H negative ion source at IPP-Nagoya

Energy Technology Data Exchange (ETDEWEB)

Okamura, H; Kuroda, T; Miyahara, A

1981-02-01

Test facilities for the development of magnetron H(-) ion source consists of the vacuum system, power supplies, diagnostic equipment, and their controlling electronics. Schematics are presented and relevant items described including sequence control, optical links, the charged pulse forming network, the extractor power supply, magnet power supply, temperature control of the cesium feeder, and the pulsed valve driver. Noise problems and diagnostics are also considered.

Magnetic properties of in-plane oriented barium hexaferrite thin films prepared by direct current magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaozhi; Yue, Zhenxing, E-mail: yuezhx@mail.tsinghua.edu.cn; Meng, Siqin; Yuan, Lixin [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2014-12-28

In-plane c-axis oriented Ba-hexaferrite (BaM) thin films were prepared on a-plane (112{sup ¯}0) sapphire (Al{sub 2}O{sub 3}) substrates by DC magnetron sputtering followed by ex-situ annealing. The DC magnetron sputtering was demonstrated to have obvious advantages over the traditionally used RF magnetron sputtering in sputtering rate and operation simplicity. The sputtering power had a remarkable influence on the Ba/Fe ratio, the hematite secondary phase, and the grain morphology of the as-prepared BaM films. Under 80 W of sputtering power, in-plane c-axis highly oriented BaM films were obtained. These films had strong magnetic anisotropy with high hysteresis loop squareness (M{sub r}/M{sub s} of 0.96) along the in-plane easy axis and low M{sub r}/M{sub s} of 0.03 along the in-plane hard axis. X-ray diffraction patterns and pole figures revealed that the oriented BaM films grew via an epitaxy-like growth process with the crystallographic relationship BaM (101{sup ¯}0)//α-Fe{sub 2}O{sub 3}(112{sup ¯}0)//Al{sub 2}O{sub 3}(112{sup ¯}0)

The influence of target oxygen on the YBa2Cu3O6+δ DC Magnetron sputtering process

International Nuclear Information System (INIS)

Larsson, G.; Selinder, T.I.; Helmersson, U

1990-01-01

The oxygen partial pressure and the target potential have been monitored under a range of process conditions during single target dc magnetron sputtering of Y-Ba-Cu-O. The introduced sputtering gas consisted in all but one instance of pure argon and hence the oxygen present in the plasma originated mainly from the target. During the first hours of sputtering the oxygen partial pressure was of the same magnitude as the argon pressure (3.0 Pa). As the oxygen was released from the target and subsequently removed by pumping, the target potential increased and the film composition became more stoichiometric. After 30-40 hours of sputtering the target potential and the oxygen pressure stabilized and the film composition was equal to that of the stoichiometric target. If an oxygen flow exceeding a critical level was mixed into the sputtering gas the target potential and the deposition rate decreased swiftly. This was due to target oxidation, further manifested in changing plasma and target colours. In some instances the stabilization after 'presputtering' was incomplete and oscillations in target voltage and oxygen partial pressure were observed. The fluctuations made it virtually impossible to obtain stoichiometric films. The oscillative behaviour of the sputtering process is tentatively explained by a target temperature dependent oxygen diffusion. (au)

A hybrid heterojunction with reverse rectifying characteristics fabricated by magnetron sputtered TiOx and plasma polymerized aniline structure

International Nuclear Information System (INIS)

Sarma, Bimal K; Pal, Arup R; Bailung, Heremba; Chutia, Joyanti

2012-01-01

A TiO x film produced by direct current reactive magnetron sputtering without substrate heating or post-deposition annealing and a plasma polymerized aniline (PPA) structure deposited in the same reactor by a radio-frequency glow discharge without the assistance of a carrier gas are used for the fabrication of a heterojunction. The gas phase discharge is investigated by a Langmuir probe and optical emission spectroscopy. The individual layers and the heterojunction are characterized for structural and optoelectronic properties. PPA has polymer-like structure and texture and is characterized by saturated-unsaturated, branched and crosslinked networks. X-ray photoelectron spectroscopy reveals a slightly reduced TiO x surface, which exhibits near band edge luminescence. The free radicals trapped in PPA readily react with oxygen when exposed to atmosphere. The heterojunction shows reverse rectifying characteristics under dark and ultraviolet (UV) irradiation. The energy levels of TiO x and PPA might exhibit reverse band bending and electrons and holes are accumulated on both sides of the heterojunction. The charge accumulation phenomena at the interface may play a key role in the device performance of a hybrid heterojunction. The current-voltage characteristic of the heterojunction is sensitive to UV light, so the structure may be used for photo-sensing applications. (paper)

Local heteroepitaxy as an adhesion mechanism in aluminium coatings cold gas sprayed on AlN substrates

International Nuclear Information System (INIS)

Wüstefeld, Christina; Rafaja, David; Motylenko, Mykhaylo; Ullrich, Christiane; Drehmann, Rico; Grund, Thomas; Lampke, Thomas; Wielage, Bernhard

2017-01-01

Cold gas sprayed Al coatings deposited onto wurtzitic AlN substrates show excellent adhesion. As a possible adhesion mechanism, the local heteroepitaxy between Al and AlN was considered and verified experimentally in Al coatings, which were deposited using magnetron sputtering or cold gas spraying on single-crystalline and polycrystalline AlN substrates. Analysis of the local orientation relationships at the Al/AlN interfaces revealed that preferentially such lattice planes of Al align parallel with the upright lattice planes of AlN, which possess similar interplanar distances. The matching lattice planes in the Al coatings grew as continuations of the lattice planes in the AlN substrates. In all samples under study, the parallel alignment of the lattice planes {220}_A_l and {110}_A_l_N was found. Additional orientation relationships between Al and AlN arose if parallel lattice planes with similar interplanar spacing could be found in both counterparts via rotation of the lattice planes {220}_A_l around their normal direction. Still, the oriented growth of Al on AlN is only possible if Al atoms in the deposited coatings are mobile enough to rearrange along the AlN surface. Whereas the mobility of Al atoms in a magnetron sputtering process is expected to be sufficiently high, the intrinsic mobility of Al atoms in the cold gas sprayed particles is anticipated to be low. However, the auxiliary microstructure analyses have shown that local recrystallization and partial melting are two phenomena, which can facilitate the rearrangement of Al atoms within the cold gas sprayed coating.

High frequency pulse anodising of magnetron sputtered Al–Zr and Al–Ti Coatings

DEFF Research Database (Denmark)

Gudla, Visweswara Chakravarthy; Bordo, Kirill; Engberg, Sara

2016-01-01

High frequency pulse anodising of Al–Zr and Al–Ti coatings is studied as a surface finishing technique and compared to conventional decorative DC anodising. The Al–Zr and Al–Ti coatings were deposited using DC magnetron sputtering and were heat treated after deposition to generate a multiphase mi...

Investigation of photocatalytic activity of titanium dioxide deposited on metallic substrates by DC magnetron sputtering

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Canulescu, Stela; Dirscherl, Kai

2013-01-01

The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology of the c......The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology...... sweep voltammetry, impedance measurements. The microstructure and surface morphology of the coating were similar irrespective of the nature of the substrate, while the photocatalytic behaviour was found to vary depending on the substrate type. In general the TiO2 coating on stainless steel was shown...

Low temperature magnetron sputter deposition of polycrystalline silicon thin films using high flux ion bombardment

International Nuclear Information System (INIS)

Gerbi, Jennifer E.; Abelson, John R.

2007-01-01

We demonstrate that the microstructure of polycrystalline silicon thin films depends strongly on the flux of low energy ions that bombard the growth surface during magnetron sputter deposition. The deposition system is equipped with external electromagnetic coils which, through the unbalanced magnetron effect, provide direct control of the ion flux independent of the ion energy. We report the influence of low energy ( + on the low temperature ( + ions to silicon neutrals (J + /J 0 ) during growth by an order of magnitude (from 3 to 30) enables the direct nucleation of polycrystalline Si on glass and SiO 2 coated Si at temperatures below 400 degree sign C. We discuss possible mechanisms for this enhancement of crystalline microstructure, including the roles of enhanced adatom mobility and the formation of shallow, mobile defects

Tribological properties, corrosion resistance and biocompatibility of magnetron sputtered titanium-amorphous carbon coatings

International Nuclear Information System (INIS)

Dhandapani, Vishnu Shankar; Subbiah, Ramesh; Thangavel, Elangovan; Arumugam, Madhankumar; Park, Kwideok; Gasem, Zuhair M.; Veeraragavan, Veeravazhuthi; Kim, Dae-Eun

2016-01-01

Highlights: • a-C:Ti nanocomposite coatings were prepared on 316L stainless steel by using R.F. magnetron sputtering method. • Properties of the nanocomposite coatings were analyzed with respect to titanium content. • Corrosion resistance, biocompatibility and hydrophobicity of nanocomposite coating were enhanced with increasing titanium content. • Coating with 2.33 at.% titanium showed superior tribological properties compared to other coatings. - Abstract: Amorphous carbon incorporated with titanium (a-C:Ti) was coated on 316L stainless steel (SS) by magnetron sputtering technique to attain superior tribological properties, corrosion resistance and biocompatibility. The morphology, topography and functional groups of the nanostructured a-C:Ti coatings in various concentrations were analyzed using atomic force microscopy (AFM), Raman, X-Ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Raman and XPS analyses confirmed the increase in sp"2 bonds with increasing titanium content in the a-C matrix. TEM analysis confirmed the composite nature of the coating and the presence of nanostructured TiC for Ti content of 2.33 at.%. This coating showed superior tribological properties compared to the other a-C:Ti coatings. Furthermore, electrochemical corrosion studies were performed against stimulated body fluid medium in which all the a-C:Ti coatings showed improved corrosion resistance than the pure a-C coating. Preosteoblasts proliferation and viability on the specimens were tested and the results showed that a-C:Ti coatings with relatively high Ti (3.77 at.%) content had better biocompatibility. Based on the results of this work, highly durable coatings with good biocompatibility could be achieved by incorporation of optimum amount of Ti in a-C coatings deposited on SS by magnetron sputtering technique.

High power impulse magnetron sputtering and its applications

Science.gov (United States)

Yan, YUAN; Lizhen, YANG; Zhongwei, LIU; Qiang, CHEN

2018-04-01

High power impulse magnetron sputtering (HiPIMS) has attracted a great deal of attention because the sputtered material is highly ionized during the coating process, which has been demonstrated to be advantageous for better quality coating. Therefore, the mechanism of the HiPIMS technique has recently been investigated. In this paper, the current knowledge of HiPIMS is described. We focus on the mechanical properties of the deposited thin film in the latest applications, including hard coatings, adhesion enhancement, tribological performance, and corrosion protection layers. A description of the electrical, optical, photocatalytic, and functional coating applications are presented. The prospects for HiPIMS are also discussed in this work.

Investigation of error sources in regional inverse estimates of greenhouse gas emissions in Canada

Science.gov (United States)

Chan, E.; Chan, D.; Ishizawa, M.; Vogel, F.; Brioude, J.; Delcloo, A.; Wu, Y.; Jin, B.

2015-08-01

Inversion models can use atmospheric concentration measurements to estimate surface fluxes. This study is an evaluation of the errors in a regional flux inversion model for different provinces of Canada, Alberta (AB), Saskatchewan (SK) and Ontario (ON). Using CarbonTracker model results as the target, the synthetic data experiment analyses examined the impacts of the errors from the Bayesian optimisation method, prior flux distribution and the atmospheric transport model, as well as their interactions. The scaling factors for different sub-regions were estimated by the Markov chain Monte Carlo (MCMC) simulation and cost function minimization (CFM) methods. The CFM method results are sensitive to the relative size of the assumed model-observation mismatch and prior flux error variances. Experiment results show that the estimation error increases with the number of sub-regions using the CFM method. For the region definitions that lead to realistic flux estimates, the numbers of sub-regions for the western region of AB/SK combined and the eastern region of ON are 11 and 4 respectively. The corresponding annual flux estimation errors for the western and eastern regions using the MCMC (CFM) method are -7 and -3 % (0 and 8 %) respectively, when there is only prior flux error. The estimation errors increase to 36 and 94 % (40 and 232 %) resulting from transport model error alone. When prior and transport model errors co-exist in the inversions, the estimation errors become 5 and 85 % (29 and 201 %). This result indicates that estimation errors are dominated by the transport model error and can in fact cancel each other and propagate to the flux estimates non-linearly. In addition, it is possible for the posterior flux estimates having larger differences than the prior compared to the target fluxes, and the posterior uncertainty estimates could be unrealistically small that do not cover the target. The systematic evaluation of the different components of the inversion

Composition and optical properties tunability of hydrogenated silicon carbonitride thin films deposited by reactive magnetron sputtering

Science.gov (United States)

Bachar, A.; Bousquet, A.; Mehdi, H.; Monier, G.; Robert-Goumet, C.; Thomas, L.; Belmahi, M.; Goullet, A.; Sauvage, T.; Tomasella, E.

2018-06-01

Radiofrequency reactive magnetron sputtering was used to deposit hydrogenated amorphous silicon carbonitride (a-SiCxNy:H) at 400 °C by sputtering a silicon target under CH4 and N2 reactive gas mixture. Rutherford backscattering spectrometry revealed that the change of reactive gases flow rate (the ratio R = FN2/(FN2+FCH4)) induced a smooth chemical composition tunability from a silicon carbide-like film for R = 0 to a silicon nitride-like one at R = 1 with a large area of silicon carbonitrides between the two regions. The deconvolution of Fourier Transform InfraRed and X-ray photoelectron spectroscopy spectrum highlighted a shift of the chemical environment of the deposited films corresponding to the changes seen by RBS. The consequence of these observations is that a control of refractive index in the range of [1.9-2.5] at λ = 633 nm and optical bandgap in the range [2 eV-3.8 eV] have been obtained which induces that these coatings can be used as antireflective coatings in silicon photovoltaic cells.

Study of aroma scalping through thermosealable polymers used in food packaging by inverse gas chromatography.

Science.gov (United States)

Gavara, R; Catalá, R; Hernández-Muñoz, P

1997-01-01

Scalping of aroma components in polymers used for food packaging was determined by solubility experiments. Aromas were selected from different families: esters, alcohols, hydrocarbons and ketones. Polymers were a linear low density polyethylene (LLDPE), an ionomer and a new thermosealable polyester (PET). Polymers were selected from thermosealable materials because of their resistance to fats and oils. Sorption isotherms (low sorbate activity range) for every system aroma (vapour)/polymer were determined by inverse gas chromatography. Isotherms were found to be linear. Hence, solubility coefficients (S) as defined by Henry's law were calculated from the isotherm slopes. According to S values, PET appears to be the best choice to minimize aroma scalping by sorption in the packaging inner layer, Ionomers improve the barrier to aroma when compared with LLDPE except for polar sorbates. Sorption of aroma components was shown to be selective, e.g. limonene was preferentially sorbed in LLDPE. The value of S for the limonene/LLDPE system was 2.5 times the value of S for ethyl caproate/LLDPE. This selectivity may lead to an imbalance in the flavour and may be more important than the prevention of overall scalping.

Influence of stress on the structural and dielectric properties of rf magnetron sputtered zinc oxide thin film

Science.gov (United States)

Menon, Rashmi; Sreenivas, K.; Gupta, Vinay

2008-05-01

Highly c axis oriented zinc oxide (ZnO) thin films have been prepared on 1737 Corning glass substrate by planar rf magnetron sputtering under varying pressure (10-50mTorr) and different oxygen percentage (40%-100%) in reactive gas mixtures. The as-grown ZnO thin films were found to have stress over a wide range from -6×1010to-9×107dynes/cm2. The presence of stress depends strongly on processing conditions, and films become almost stress free under a unique combination of sputtering pressure and reactive gas composition. The studies show a correlation of stress with structural and electrical properties of the ZnO thin film. The stressed films possess high electrical conductivity and exhibits strong dielectric dispersion over a wide frequency (1kHz-1MHz). The dielectric constant ɛ'(ω) of stress free ZnO film was almost frequency independent and was close to the bulk value. The measured value of dc conductivity, σdc(ω) and ac conductivity σac(ω) of stress free ZnO film was 1.3×10-9 and 6.8×10-5Ω-1cm-1, respectively. The observed variation in the structural and electrical properties of ZnO thin film with stress has been analyzed in the light of growth kinetics.

The Optimum Fabrication Condition of p-Type Antimony Tin Oxide Thin Films Prepared by DC Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Huu Phuc Dang

2016-01-01

Full Text Available Transparent Sb-doped tin oxide (ATO thin films were fabricated on quartz glass substrates via a mixed (SnO2 + Sb2O3 ceramic target using direct current (DC magnetron sputtering in ambient Ar gas at a working pressure of 2 × 10−3 torr. X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, Hall-effect, and UV-vis spectra measurements were performed to characterize the deposited films. The substrate temperature of the films was investigated in two ways: (1 films were annealed in Ar ambient gas after being deposited at room temperature or (2 they were deposited directly at different temperatures. The first process for fabricating the ATO films was found to be easier than the second process. The deposited films showed p-type electrical properties, a polycrystalline tetragonal rutile structure, and their average transmittance was greater than 80% in the visible light range at the optimum annealing temperature of 500°C. The best electrical properties of the film were obtained on a 10 wt% Sb2O3-doped SnO2 target with a resistivity, hole concentration, and Hall mobility of 0.55 Ω·cm, 1.2 × 1019 cm−3, and 0.54 cm2V−1s−1, respectively.

Two-dimensional spatial survey of the plasma potential and electric field in a pulsed bipolar magnetron discharge

International Nuclear Information System (INIS)

Vetushka, A.; Karkari, S.K.; Bradley, J.W.

2004-01-01

Emissive and Langmuir probe techniques have been used to obtain two-dimensional (2D) spatial maps of the plasma potential V p , electric field E, and ion trajectories in a pulsed bipolar magnetron discharge. The magnetron was pulsed at a frequency of 100 kHz, with a 50% duty cycle and operated at an argon pressure of 0.74 Pa. The pulse wave form was characterized by three distinct phases: the 'overshoot', 'reverse', and 'on' phases. In the 'on' phase of the pulse, when the cathode voltage is driven to -670 V, the 2D spatial distribution of V p has a similar form to that in dc magnetron, with significant axial and radial electric fields in the bulk plasma, accelerating ions to the sheath edge above the cathode racetrack region. During the 'overshoot' phase (duration 200 ns), V p is raised to values greater than +330 V, more than 100 V above the cathode potential, with E pointing away from the target. In the 'reverse' phase V p has a value of +45 V at all measured positions, 2 V more positive than the target potential. In this phase there is no electric field present in the plasma. In the bulk of the plasma, the results from Langmuir probe and the emissive probe are in good agreement, however, in one particular region of the plasma outside the radius of the cathode, the emissive probe measurements are consistently more positive (up to 45 V in the 'on' time). This discrepancy is discussed in terms of the different frequency response of the probes and their perturbation of the plasma. A simple circuit model of the plasma-probe system has been proposed to explain our results. A brief discussion of the effect of the changing plasma potential distribution on the operation of the magnetron is given

Time-resolved investigation of an asymmetric bipolar pulsed magnetron deposition discharge: Influence of pressure

NARCIS (Netherlands)

Dunger, Th.; Welzel, Th.; Welzel, S.; Richter, F.

2005-01-01

A bipolar pulsed magnetron deposition discharge has been studied with pulse frequencies of 100 and 150 kHz, respectively. The discharge was operated in an argon/oxygen mixture at different total pressures with a circular magnesium target as cathode. Time-resolved Langmuir double probe measurements

Deposition of copper coatings in a magnetron with liquid target

Energy Technology Data Exchange (ETDEWEB)

Tumarkin, A. V., E-mail: sanyahrustal@mail.ru; Kaziev, A. V.; Kolodko, D. V.; Pisarev, A. A.; Kharkov, M. M.; Khodachenko, G. V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

2015-12-15

Copper coatings were deposited on monocrystalline Si substrates using a magnetron discharge with a liquid cathode in the metal vapour plasma. During the deposition, the bias voltage in the range from 0 V to–400 V was applied to the substrate. The prepared films were investigated by a scanning electron microscope, and their adhesive properties were studied using a scratch tester. It was demonstrated that the adhesion of the deposited films strongly depends on the bias voltage and varies in a wide range.

Constraining the Magmatic System at Mount St. Helens (2004-2008) Using Bayesian Inversion With Physics-Based Models Including Gas Escape and Crystallization

International Nuclear Information System (INIS)

Wong, Ying-Qi; Segall, Paul; Bradley, Andrew; Anderson, Kyle

2017-01-01

Physics-based models of volcanic eruptions track conduit processes as functions of depth and time. When used in inversions, these models permit integration of diverse geological and geophysical data sets to constrain important parameters of magmatic systems. We develop a 1-D steady state conduit model for effusive eruptions including equilibrium crystallization and gas transport through the conduit and compare with the quasi-steady dome growth phase of Mount St. Helens in 2005. Viscosity increase resulting from pressure-dependent crystallization leads to a natural transition from viscous flow to frictional sliding on the conduit margin. Erupted mass flux depends strongly on wall rock and magma permeabilities due to their impact on magma density. Including both lateral and vertical gas transport reveals competing effects that produce nonmonotonic behavior in the mass flux when increasing magma permeability. Using this physics-based model in a Bayesian inversion, we link data sets from Mount St. Helens such as extrusion flux and earthquake depths with petrological data to estimate unknown model parameters, including magma chamber pressure and water content, magma permeability constants, conduit radius, and friction along the conduit walls. Even with this relatively simple model and limited data, we obtain improved constraints on important model parameters. We find that the magma chamber had low (<5 wt %) total volatiles and that the magma permeability scale is well constrained at ~10 –11.4 m 2 to reproduce observed dome rock porosities. Here, compared with previous results, higher magma overpressure and lower wall friction are required to compensate for increased viscous resistance while keeping extrusion rate at the observed value.

Validation of the Swiss methane emission inventory by atmospheric observations and inverse modelling

Directory of Open Access Journals (Sweden)

S. Henne

2016-03-01

Full Text Available Atmospheric inverse modelling has the potential to provide observation-based estimates of greenhouse gas emissions at the country scale, thereby allowing for an independent validation of national emission inventories. Here, we present a regional-scale inverse modelling study to quantify the emissions of methane (CH4 from Switzerland, making use of the newly established CarboCount-CH measurement network and a high-resolution Lagrangian transport model. In our reference inversion, prior emissions were taken from the "bottom-up" Swiss Greenhouse Gas Inventory (SGHGI as published by the Swiss Federal Office for the Environment in 2014 for the year 2012. Overall we estimate national CH4 emissions to be 196 ± 18 Gg yr−1 for the year 2013 (1σ uncertainty. This result is in close agreement with the recently revised SGHGI estimate of 206 ± 33 Gg yr−1 as reported in 2015 for the year 2012. Results from sensitivity inversions using alternative prior emissions, uncertainty covariance settings, large-scale background mole fractions, two different inverse algorithms (Bayesian and extended Kalman filter, and two different transport models confirm the robustness and independent character of our estimate. According to the latest SGHGI estimate the main CH4 source categories in Switzerland are agriculture (78 %, waste handling (15 % and natural gas distribution and combustion (6 %. The spatial distribution and seasonal variability of our posterior emissions suggest an overestimation of agricultural CH4 emissions by 10 to 20 % in the most recent SGHGI, which is likely due to an overestimation of emissions from manure handling. Urban areas do not appear as emission hotspots in our posterior results, suggesting that leakages from natural gas distribution are only a minor source of CH4 in Switzerland. This is consistent with rather low emissions of 8.4 Gg yr−1 reported by the SGHGI but inconsistent with the much higher value of 32 Gg yr−1 implied by the

Nanostructured ZnO films for potential use in LPG gas sensors

Science.gov (United States)

Latyshev, V. M.; Berestok, T. O.; Opanasyuk, A. S.; Kornyushchenko, A. S.; Perekrestov, V. I.

2017-05-01

The aim of the work was to obtain ZnO nanostructures with heightened surface area and to study relationship between formation method and gas sensor properties towards propane-butane mixture (LPG). In order to synthesize ZnO nanostructures chemical and physical formation methods have been utilized. The first one was chemical bath deposition technology and the second one magnetron sputtering of Zn followed by oxidation. Optimal method and technological parameters corresponding to formation of material with the highest sensor response have been determined experimentally. Dynamical gas sensor response at different temperature values and dependencies of the sensor sensitivity on the temperature at different LPG concentrations in air have been investigated. It has been found, that sensor response depends on the sample morphology and has the highest value for the structure consisting of thin nanowires. The factors that lead to the decrease in the gas sensor operating temperature have been determined.

Examination of the radiation of magnetron discharge in the process of spraying thin films

International Nuclear Information System (INIS)

Sokolov, V.F.; Sokolova, Yu.A.; Protasevich, A.A.

1999-01-01

In this work, we investigated the light radiation of the magnetron discharge in order to develop a method of spectral control and regulation of the process of deposition of thin films in UVN-25 industrial equipment used for metallising of superlarge integrated circuits and other components

Measurements of mass-fraction activity coefficient at infinite dilution of aliphatic and aromatic hydrocarbons, thiophene, alcohols, water, ethers, and ketones in hyperbranched polymer, Boltorn H2004, using inverse gas chromatography

International Nuclear Information System (INIS)

Domanska, Urszula; Zolek-Tryznowska, Zuzanna

2010-01-01

Thermodynamic properties of the hyperbranched polymer, Boltorn H2004 (B-H2004), were investigated by inverse gas chromatography with 42 different solvents: n-alkanes (C 5 -C 10 ), cycloalkanes (C 5 -C 8 ), alkenes (C 5 -C 8 ), alkynes (C 5 -C 8 ), aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-, m-, p-xylene, thiophene), alcohols (C 1 -C 5 ), water, ethers (tetrahydrofuran (THF), methyl-tert-butylether (MTBE), diethyl-, di-n-propyl-, di-n-butyl ether), and ketones (acetone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, cyclopentanone) at the temperatures from (308.15 to 348.15) K using the inverse gas chromatography (IGC). The density and thermophysical properties of polymer were described. The specific retention volume (V g ), the mass-fraction activity coefficient at infinite dilution (Ω 13 ∞ ), the Flory-Huggins interaction parameter (χ 13 ∞ ), the molar enthalpy of sorption in the polymer (Δ s H), the partial molar excess enthalpy at infinite dilution (ΔH 1 E,∞ ), the molar enthalpy of vaporization to the ideal-gas state for the pure solutes (Δ vap H 0 ), the partial molar Gibbs excess energy at infinite dilution (ΔG 1 E,∞ ), and the solubility parameter of the polymer (δ 3 ), were calculated. The UNIFAC-FV model was used to predict the mass-fraction activity coefficient at infinite dilution for different solutes in the B-H2004 polymer.

RF Magnetron Sputtering Coating Of Hydroxyapatite On Alkali Solution Treated Titanate Nanorods

Directory of Open Access Journals (Sweden)

Lee K.

2015-06-01

Full Text Available Hydroxyapatite (HA is a material with outstanding biocompatibility. It is chemically similar to natural bone tissue, and has therefore been favored for use as a coating material for dental and orthopedic implants. In this study, RF magnetron sputtering was applied for HA coating. And Alkali treatment was performed in a 5 M NaOH solution at 60°C. The coated HA thin film was heat-treated at a range of temperatures from 300 to 600°C. The morphological characterization and crystal structures of the coated specimens were then obtained via FE-SEM, XRD, and FT-IR. The amorphous thin film obtained on hydrothermally treated nanorods transformed into a crystalline thin film after the heat treatment. The change in the phase transformation, with an enhanced crystallinity, showed a reduced wettability. The hydrothermally treated nanorods with an amorphous thin film, on the other hand, showed an outstanding wettability. The HA thin film perpendicularly coated the nanorods in the upper and inner parts via RF magnetron sputtering, and the FT-IR results confirmed that the molecular bonding of the coated film had an HA structure.

Quantitative Prediction of Coalbed Gas Content Based on Seismic Multiple-Attribute Analyses

Directory of Open Access Journals (Sweden)

Renfang Pan

2015-09-01

Full Text Available Accurate prediction of gas planar distribution is crucial to selection and development of new CBM exploration areas. Based on seismic attributes, well logging and testing data we found that seismic absorption attenuation, after eliminating the effects of burial depth, shows an evident correlation with CBM gas content; (positive structure curvature has a negative correlation with gas content; and density has a negative correlation with gas content. It is feasible to use the hydrocarbon index (P*G and pseudo-Poisson ratio attributes for detection of gas enrichment zones. Based on seismic multiple-attribute analyses, a multiple linear regression equation was established between the seismic attributes and gas content at the drilling wells. Application of this equation to the seismic attributes at locations other than the drilling wells yielded a quantitative prediction of planar gas distribution. Prediction calculations were performed for two different models, one using pre-stack inversion and the other one disregarding pre-stack inversion. A comparison of the results indicates that both models predicted a similar trend for gas content distribution, except that the model using pre-stack inversion yielded a prediction result with considerably higher precision than the other model.

Novel automated inversion algorithm for temperature reconstruction using gas isotopes from ice cores

Directory of Open Access Journals (Sweden)

M. Döring

2018-06-01

Full Text Available Greenland past temperature history can be reconstructed by forcing the output of a firn-densification and heat-diffusion model to fit multiple gas-isotope data (δ15N or δ40Ar or δ15Nexcess extracted from ancient air in Greenland ice cores using published accumulation-rate (Acc datasets. We present here a novel methodology to solve this inverse problem, by designing a fully automated algorithm. To demonstrate the performance of this novel approach, we begin by intentionally constructing synthetic temperature histories and associated δ15N datasets, mimicking real Holocene data that we use as true values (targets to be compared to the output of the algorithm. This allows us to quantify uncertainties originating from the algorithm itself. The presented approach is completely automated and therefore minimizes the subjective impact of manual parameter tuning, leading to reproducible temperature estimates. In contrast to many other ice-core-based temperature reconstruction methods, the presented approach is completely independent from ice-core stable-water isotopes, providing the opportunity to validate water-isotope-based reconstructions or reconstructions where water isotopes are used together with δ15N or δ40Ar. We solve the inverse problem T(δ15N, Acc by using a combination of a Monte Carlo based iterative approach and the analysis of remaining mismatches between modelled and target data, based on cubic-spline filtering of random numbers and the laboratory-determined temperature sensitivity for nitrogen isotopes. Additionally, the presented reconstruction approach was tested by fitting measured δ40Ar and δ15Nexcess data, which led as well to a robust agreement between modelled and measured data. The obtained final mismatches follow a symmetric standard-distribution function. For the study on synthetic data, 95 % of the mismatches compared to the synthetic target data are in an envelope between 3.0 to 6.3 permeg for δ15N and 0.23 to 0

Process stabilization by peak current regulation in reactive high-power impulse magnetron sputtering of hafnium nitride

International Nuclear Information System (INIS)

Shimizu, T; Villamayor, M; Helmersson, U; Lundin, D

2016-01-01

A simple and cost effective approach to stabilize the sputtering process in the transition zone during reactive high-power impulse magnetron sputtering (HiPIMS) is proposed. The method is based on real-time monitoring and control of the discharge current waveforms. To stabilize the process conditions at a given set point, a feedback control system was implemented that automatically regulates the pulse frequency, and thereby the average sputtering power, to maintain a constant maximum discharge current. In the present study, the variation of the pulse current waveforms over a wide range of reactive gas flows and pulse frequencies during a reactive HiPIMS process of Hf-N in an Ar–N 2 atmosphere illustrates that the discharge current waveform is a an excellent indicator of the process conditions. Activating the reactive HiPIMS peak current regulation, stable process conditions were maintained when varying the N 2 flow from 2.1 to 3.5 sccm by an automatic adjustment of the pulse frequency from 600 Hz to 1150 Hz and consequently an increase of the average power from 110 to 270 W. Hf–N films deposited using peak current regulation exhibited a stable stoichiometry, a nearly constant power-normalized deposition rate, and a polycrystalline cubic phase Hf-N with (1 1 1)-preferred orientation over the entire reactive gas flow range investigated. The physical reasons for the change in the current pulse waveform for different process conditions are discussed in some detail. (paper)

Microstructure and electrical properties of bismuth and bismuth oxide deposited by magnetron sputtering UBM; Microestructura y propiedades electricas de bismuto y oxido de bismuto depositados por magnetron sputtering UBM

Energy Technology Data Exchange (ETDEWEB)

Otalora B, D. M.; Dussan, A. [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Carrera 30 No. 45-03, 111321 Bogota (Colombia); Olaya F, J. J., E-mail: jjolayaf@unal.edu.co [Universidad Nacional de Colombia, Facultad de Ingenieria, Departamento de Ingenieria Mecanica y Mecatronica, Carrera 30 No. 45-03, 111321 Bogota (Colombia)

2015-07-01

In this work, bismuth (Bi) and bismuth oxide (Bi{sub 2}O{sub 3}) thin films were prepared, at room temperature, by Sputtering Unbalanced Magnetron (UBM - Unbalance Magnetron) technique under glass substrates. Microstructural and electrical properties of the samples were studied by X-ray diffraction (XRD) and System for Measuring Physical Properties - PPMS (Physical Property Measurement System). Dark resistivity of the material was measured for a temperature range between 100 and 400 K. From the XRD measurements it was observed a polycrystalline character of the Bi associated to the presence of phases above the main peak, 2θ = 26.42 grades and a growth governed by a rhombohedral structure. Crystal parameters were obtained for both compounds, Bi and Bi{sub 2}O{sub 3}. From the analysis of the spectra of the conductivity as a function of temperature, it was established that the transport mechanism that governs the region of high temperature (T>300 K) is thermally activated carriers. From conductivity measurements the activation energies were obtained of 0.0094 eV and 0.015 eV for Bi{sub 2}O{sub 3} and Bi, respectively. (Author)

Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

Science.gov (United States)

Alden, Caroline B.; Ghosh, Subhomoy; Coburn, Sean; Sweeney, Colm; Karion, Anna; Wright, Robert; Coddington, Ian; Rieker, Gregory B.; Prasad, Kuldeep

2018-03-01

Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m), integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB). The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells) through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model-data mismatch. It is also tested with field observations of (1) a non-leaking source location and (2) a source location where a controlled emission of 3.1 × 10-5 kg s-1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests). The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability) and measurement uncertainty of 5 ppb (1σ), when measurements are averaged over 2 min. The

Tin dioxide opals and inverted opals: near-ideal microstructures for gas sensors

Energy Technology Data Exchange (ETDEWEB)

Scott, R.W.J.; Yang, S.M.; Coombs, N.; Ozin, G.A. [Toronto Univ., ON (Canada). Materials Chemistry Research Group; Chabanis, G.; Williams, D.E. [University Coll., London (United Kingdom). Dept. of Chemistry

2001-10-02

Periodic macroporous forms of nc-SnO{sub 2} have been synthesized by two methods, giving opals and inverse opals that can be used as structurally well-defined gas sensors, as demonstrated for CO gas, as well as for toluene and ethanol vapors. The inverse opals, in particular, seem to approximate ''ideal'' behavior. (orig.)

Nucleation of ultrathin silver layer by magnetron sputtering in Ar/N2 plasma

Czech Academy of Sciences Publication Activity Database

Bulíř, Jiří; Novotný, Michal; Lančok, Ján; Fekete, Ladislav; Drahokoupil, Jan; Musil, Jindřich

2013-01-01

Roč. 228, č. 1 (2013), S86-S90 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR GP202/09/P324 Institutional support: RVO:68378271 Keywords : ultrathin silver * magnetron sputtering * spectral ellipsometry * in-situ monitoring Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.199, year: 2013

Time-resolved investigation of dual high power impulse magnetron sputtering with closed magnetic field during deposition of Ti-Cu thin films

International Nuclear Information System (INIS)

Stranak, Vitezslav; Hippler, Rainer; Cada, Martin; Hubicka, Zdenek; Tichy, Milan

2010-01-01

Time-resolved comparative study of dual magnetron sputtering (dual-MS) and dual high power impulse magnetron sputtering (dual-HiPIMS) systems arranged with closed magnetic field is presented. The dual-MS system was operated with a repetition frequency 4.65 kHz (duty cycle ≅50%). The frequency during dual-HiPIMS is lower as well as its duty cycle (f=100 Hz, duty 1%). Different metallic targets (Ti, Cu) and different cathode voltages were applied to get required stoichiometry of Ti-Cu thin films. The plasma parameters of the interspace between magnetrons in the substrate position were investigated by time-resolved optical emission spectroscopy, Langmuir probe technique, and measurement of ion fluxes to the substrate. It is shown that plasma density as well as ion flux is higher about two orders of magnitude in dual-HiPIMS system. This fact is partially caused by low diffusion of ionized sputtered particles (Ti + ,Cu + ) which creates a preionized medium.

Atmospheric inverse modeling with known physical bounds: an example from trace gas emissions

Directory of Open Access Journals (Sweden)

S. M. Miller

2014-02-01

the relative merits of each. This paper investigates the applicability of several approaches to bounded inverse problems. A common method of data transformations is found to unrealistically skew estimates for the examined example application. The method of Lagrange multipliers and two Markov chain Monte Carlo (MCMC methods yield more realistic and accurate results. In general, the examined MCMC approaches produce the most realistic result but can require substantial computational time. Lagrange multipliers offer an appealing option for large, computationally intensive problems when exact uncertainty bounds are less central to the analysis. A synthetic data inversion of US anthropogenic methane emissions illustrates the strengths and weaknesses of each approach.

Inverse photoemission

International Nuclear Information System (INIS)

Namatame, Hirofumi; Taniguchi, Masaki

1994-01-01

Photoelectron spectroscopy is regarded as the most powerful means since it can measure almost perfectly the occupied electron state. On the other hand, inverse photoelectron spectroscopy is the technique for measuring unoccupied electron state by using the inverse process of photoelectron spectroscopy, and in principle, the similar experiment to photoelectron spectroscopy becomes feasible. The development of the experimental technology for inverse photoelectron spectroscopy has been carried out energetically by many research groups so far. At present, the heightening of resolution of inverse photoelectron spectroscopy, the development of inverse photoelectron spectroscope in which light energy is variable and so on are carried out. But the inverse photoelectron spectroscope for vacuum ultraviolet region is not on the market. In this report, the principle of inverse photoelectron spectroscopy and the present state of the spectroscope are described, and the direction of the development hereafter is groped. As the experimental equipment, electron guns, light detectors and so on are explained. As the examples of the experiment, the inverse photoelectron spectroscopy of semimagnetic semiconductors and resonance inverse photoelectron spectroscopy are reported. (K.I.)

Interfacial Structure and Photocatalytic Activity of Magnetron Sputtered TiO2 on Conducting Metal Substrates

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Petit, Jean-Pierre; Mermoux, Michel

2014-01-01

The photocatalytic behavior of magnetron sputtered anatase TiO2 coatings on copper, nickel, and gold was investigated with the aim of understanding the effect of the metallic substrate and coating-substrate interface structure. Stoichiometry and nanoscale structure of the coating were investigated...

Residual stress and texture in Aluminum doped Zinc Oxide layers deposited by reactive radio frequency magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Azanza Ricardo, C.L., E-mail: Cristy.Azanza@ing.unitn.it [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy); Pastorelli, M.; D' Incau, M. [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy); Aswath, P. [College of Engineering, University of Texas at Arlington, TX (United States); Scardi, P. [Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 via Mesiano 77, Trento (Italy)

2016-04-30

Aluminum doped Zinc Oxide thin films were deposited on standard soda-lime substrates by reactive radio frequency magnetron sputtering. Residual stress and texture were studied by X-ray diffraction, while X-ray Absorption Near Edge Spectroscopy provided information on the Al environment in the best performing thin films. The influence of deposition parameters on structural and microstructural properties is discussed. A correlation between microstructure and residual stress state with electrical and optical properties is proposed. - Highlights: • Al doped ZnO thin films were obtained by reactive radio frequency magnetron sputtering. • Correlation of stresses and texture with electrical and optical properties is shown. • Homogeneous and stress-free thin-films are the best performing ones. • XANES confirmed the doping mechanism and excluded some spurious phases.

Tropospheric nitrogen dioxide inversions based on spectral measurements of scattered sunlight

NARCIS (Netherlands)

Vlemmix, T.

2011-01-01

This thesis describes the development of inversion methods for tropospheric nitrogen dioxide (NO2), based on ground based observations of scattered sunlight with themulti-axis differential optical absorption spectroscopy (MAX-DOAS) technique. NO2 is an atmospheric trace gas which, when present near

Observation of inverse hysteresis in the E to H mode transitions in inductively coupled plasmas

International Nuclear Information System (INIS)

Lee, Min-Hyong; Chung, Chin-Wook

2010-01-01

An inverse hysteresis is observed during the E mode to H mode transition in low pressure argon inductively coupled plasmas. The transition is accompanied by an evolution of electron energy distribution from the bi-Maxwellian to the Maxwellian distribution. The mechanism of this inversion is not clear. However, we think that the bi-Maxwellian electron energy distribution in E mode, where the proportion of high energy electron is much higher than the Maxwellian distribution, would be one of the reasons for the observed inverse hysteresis. As the gas pressure increases, the inverse hysteresis disappears and the E to H mode transition follows the scenario of usual hysteresis.

DC Magnetron sputtering of Y-Ba-Cu-O thin films

International Nuclear Information System (INIS)

Larsson, Gunnar.

1990-01-01

I have been studying dc magnetron sputtering of thin film YBa 2 Cu 3 O 6+x , one of the recently discovered high- temperatures superconductors. In the introduction a brief review of the subjects sputtering and superconductivity is given. Since partial pressure measurements, especially for oxygen, have been important in the work I include a short description of the operating principles of mass spectroscopy. Experimental results in addition to what is given in the papers concerning plasma are presented in an appendix at the end of the introduction. (au)

Development of thin film cathodes for lithium-ion batteries in the material system Li–Mn–O by r.f. magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Fischer, J., E-mail: julian.fischer@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Applied Materials Physics (IAM-AWP), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Adelhelm, C.; Bergfeldt, T. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Applied Materials Physics (IAM-AWP), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Chang, K. [RWTH Aachen University, Materials Chemistry, Kopernikusstrasse 10, 46 52074 Aachen (Germany); Ziebert, C.; Leiste, H.; Stüber, M.; Ulrich, S. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Applied Materials Physics (IAM-AWP), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Music, D.; Hallstedt, B. [RWTH Aachen University, Materials Chemistry, Kopernikusstrasse 10, 46 52074 Aachen (Germany); Seifert, H.J. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Applied Materials Physics (IAM-AWP), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2013-01-01

Today most commercially available lithium ion batteries are still based on the toxic and expensive LiCoO{sub 2} as a standard cathode material. However, lithium manganese based cathode materials are cheaper and environmentally friendlier. In this work cubic-LiMn{sub 2}O{sub 4} spinel, monoclinic-Li{sub 2}MnO{sub 3} and orthorhombic-LiMnO{sub 2} thin films have been synthesized by non-reactive r.f. magnetron sputtering from two ceramic targets (LiMn{sub 2}O{sub 4}, LiMnO{sub 2}) in a pure argon discharge. The deposition parameters, namely target power and working gas pressure, were optimized in a combination with a post deposition heat treatment with respect to microstructure and electrochemical behavior. The chemical composition was determined using inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The films' crystal structure, phase evolution and morphology were investigated by X-ray diffraction, micro Raman spectroscopy and scanning electron microscopy. Due to the fact that these thin films consist of the pure active material without any impurities, such as binders or conductive additives like carbon black, they are particularly well suited for measurements of the intrinsic physical properties, which is essential for fundamental understanding. The electrochemical behavior of the cubic and the orthorhombic films was investigated by galvanostatic cycling in half cells against metallic lithium. The cubic spinel films exhibit a maximum specific capacity of ∼ 82 mAh/g, while a specific capacity of nearly 150 mAh/g can be reached for the orthorhombic counterparts. These films are promising candidates for future all solid state battery applications. - Highlights: ► Synthesis of 3 Li–Mn–O structures by one up-scalable thin film deposition method ► Formation of o-LiMnO{sub 2} by r.f. magnetron sputtering in combination with post-annealing ► Discharge capacity with o-LiMnO{sub 2} cathodes twice as high as for c

Direct hydrocarbon exploration and gas reservoir development technology

Energy Technology Data Exchange (ETDEWEB)

Kwak, Young Hoon; Oh, Jae Ho; Jeong, Tae Jin [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); and others

1995-12-01

In order to enhance the capability of petroleum exploration and development techniques, three year project (1994 - 1997) was initiated on the research of direct hydrocarbon exploration and gas reservoir development. This project consists of four sub-projects. (1) Oil(Gas) - source rock correlation technique: The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. (2) Study on surface geochemistry and microbiology for hydrocarbon exploration: the test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. (3) Development of gas and gas condensate reservoirs: There are two types of reservoir characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. (4) Numerical modeling of seismic wave propagation and full waveform inversion: Three individual sections are presented. The first one is devoted to the inversion theory in general sense. The second and the third sections deal with the frequency domain pseudo waveform inversion of seismic reflection data and refraction data respectively. (author). 180 refs., 91 figs., 60 tabs.

Study of working pressure on the optoelectrical properties of Al–Y codoped ZnO thin-film deposited using DC magnetron sputtering for solar cell applications

International Nuclear Information System (INIS)

Hsu, Feng-Hao; Wang, Na-Fu; Tsai, Yu-Zen; Chuang, Ming-Chieh; Cheng, Yu-Song; Houng, Mau-Phon

2013-01-01

Low cost transparent conductive Al–Y codoped ZnO (AZOY) thin-films were prepared on a glass substrate using a DC magnetron sputtering technique with various working pressures in the range of 5–13 mTorr. The relationship among the structural, electrical, and optical properties of sputtered AZOY films was studied as a function of working pressure. The XRD measurements show that the crystallinity of the films degraded as the working gas pressure increased. The AZOY thin-film deposited at a working pressure of 5 mTorr exhibited the lowest electrical resistivity of 4.3 × 10 −4 Ω cm, carrier mobility of 30 cm 2 /V s, highest carrier concentration of 4.9 × 10 20 cm −3 , and high transmittance in the visible region (400–800 nm) of approximately 90%. Compared with Al doped ZnO (AZO) thin-films deposited using DC or RF magnetron sputtering methods, a high carrier mobility was observed in our AZOY thin-films. This result can be used to effectively decrease the absorption of near infrared-rays in solar cell applications. The mechanisms are attributed to the larger transition energy between Ar atoms and sputtering particles and the size compensation of the dopants. Finally, the optimal quality AZOY thin-film was used as an emitter layer (or window layer) to form AZOY/n-Si heterojunction solar cells, which exhibited a stable conversion efficiency (η) of 9.4% under an AM1.5 illumination condition.

Giant Negative Piezoresistive Effect in Diamond-like Carbon and Diamond-like Carbon-Based Nickel Nanocomposite Films Deposited by Reactive Magnetron Sputtering of Ni Target

DEFF Research Database (Denmark)

Meškinis, Šaru Nas; Gudaitis, Rimantas; Šlapikas, Kęstutis

2018-01-01

deposited by either reactive HIPIMS or dc magnetron sputtering of Ni target was explained by possible clustering of the sp2-bonded carbon and/or formation of areas with the decreased hydrogen content. It was suggested that the tensile stress-induced rearrangements of these conglomerations have resulted......Piezoresistive properties of hydrogenated diamond-like carbon (DLC) and DLC-based nickel nanocomposite (DLC:Ni) films were studied in the range of low concentration of nickel nanoparticles. The films were deposited by reactive high power pulsed magnetron sputtering (HIPIMS) of Ni target, and some...... samples were deposited by direct current (dc) reactive magnetron sputtering for comparison purposes. Raman scattering spectroscopy, energy-dispersive X-ray spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS) were used to study the structure and chemical composition of the films. A four...

ZnO film deposition by DC magnetron sputtering: Effect of target configuration on the film properties

Energy Technology Data Exchange (ETDEWEB)

Arakelova, E.; Khachatryan, A.; Kteyan, A.; Avjyan, K.; Grigoryan, S.

2016-08-01

Ballistic transport model for target-to-substrate atom transfer during magnetron sputter deposition was used to develop zinc target (cathode) configuration that enabled growth of uniform zinc oxide films on extensive surfaces and provided reproducibility of films characteristics irrespective of the cathode wear-out. The advantage of the developed target configuration for high-quality ZnO film deposition was observed in the sputtering pressure range of 5− 50 mTorr, and in the range of cathode-to-substrate distances 7–20 cm. Characteristics of the deposited films were demonstrated by using X-ray diffraction analysis, as well as optical and electrical measurements. - Highlights: • Change of target configuration for optimization of magnetron sputtering deposition is proposed. • Improvement of ZnO film properties due to use of this target is demonstrated. • This configuration provided reproducibility of the deposited films properties.

Magnetron sputtered gadolinia-doped ceria diffusion barriers for metal-supported solid oxide fuel cells

DEFF Research Database (Denmark)

Sønderby, Steffen; Klemensø, Trine; Christensen, Bjarke H.

2014-01-01

Gadolinia-doped ceria (GDC) thin films are deposited by reactive magnetron sputtering in an industrial-scale setup and implemented as barrier layers between the cathode and electrolyte in metal-based solid oxide fuel cells consisting of a metal support, an electrolyte of ZrO2 co-doped with Sc2O3...

Determination of the solubility parameter of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate by inverse gas chromatography.

Science.gov (United States)

Ma, Xiaohong; Wang, Qiang; Li, Xiaoping; Tang, Jun; Zhang, Zhengfang

2015-11-01

Thermodynamic properties of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] BF4) were determined via inverse gas chromatography (IGC). Two groups of solvents with different chemical natures and polarities were used to obtain information about [BMIM] BF4-solvent interactions. The specific retention volume, molar heat of sorption, weight fraction activity coefficient, Flory-Huggins interaction parameter as well as solubility parameter were also determined in a temperature range of 333 - 373 K. The results showed that the selected solvents n-C10 to n-C12, carbon tetrachloride, cyclohexane and toluene were poor solvents for [BMIM] BF4, while dichloromethane, acetone, chloroform, methyl acetate, ethanol and methanol were favorite solvents for [BMIM] BF4. In addition, the solubility parameter of [ BMIM] BF4 was determined as 23.39 (J/cm3)0.5 by the extrapolation at 298 K. The experiment proved that IGC was a simple and accurate method to obtain the thermodynamic properties of ionic liquids. This study could be used as a reference to the application and research of the ionic liquids.

Hybrid inversions of CO2 fluxes at regional scale applied to network design

Science.gov (United States)

Kountouris, Panagiotis; Gerbig, Christoph; -Thomas Koch, Frank

2013-04-01

Long term observations of atmospheric greenhouse gas measuring stations, located at representative regions over the continent, improve our understanding of greenhouse gas sources and sinks. These mixing ratio measurements can be linked to surface fluxes by atmospheric transport inversions. Within the upcoming years new stations are to be deployed, which requires decision making tools with respect to the location and the density of the network. We are developing a method to assess potential greenhouse gas observing networks in terms of their ability to recover specific target quantities. As target quantities we use CO2 fluxes aggregated to specific spatial and temporal scales. We introduce a high resolution inverse modeling framework, which attempts to combine advantages from pixel based inversions with those of a carbon cycle data assimilation system (CCDAS). The hybrid inversion system consists of the Lagrangian transport model STILT, the diagnostic biosphere model VPRM and a Bayesian inversion scheme. We aim to retrieve the spatiotemporal distribution of net ecosystem exchange (NEE) at a high spatial resolution (10 km x 10 km) by inverting for spatially and temporally varying scaling factors for gross ecosystem exchange (GEE) and respiration (R) rather than solving for the fluxes themselves. Thus the state space includes parameters for controlling photosynthesis and respiration, but unlike in a CCDAS it allows for spatial and temporal variations, which can be expressed as NEE(x,y,t) = λG(x,y,t) GEE(x,y,t) + λR(x,y,t) R(x,y,t) . We apply spatially and temporally correlated uncertainties by using error covariance matrices with non-zero off-diagonal elements. Synthetic experiments will test our system and select the optimal a priori error covariance by using different spatial and temporal correlation lengths on the error statistics of the a priori covariance and comparing the optimized fluxes against the 'known truth'. As 'known truth' we use independent fluxes

Unbalanced Cylindrical Magnetron for Accelerating Cavities Coating

CERN Document Server

Rosaz, Guillaume; Calatroni, Sergio; Sublet, Alban; Tobarelli, Mauro

2016-01-01

We report in this paper the design and qualification of a cylindrical unbalanced magnetron source. The dedicated magnetic assemblies were simulated using a finite element model. A hall-effect magnetic probe was then used to characterize those assemblies and compared to the theoretical magnet profiles. These show a good agreement between the expected and actual values. the qualification of the different magnetic assemblies was then performed by measuring the ion flux density reaching the surface of the sample to be coated using a commercial retarding field energy analyzer. The strongest unbalanced configuration shows an increase from 0.016A.cm^-2 to 0.074A.cm^-2 of the ion flux density reaching the sample surface compared to the standard balanced configuration for a pressure 5.10^-3 mbar and a plasma source power of 300W.

Calculation of the inverse data space via sparse inversion

KAUST Repository

Saragiotis, Christos

2011-01-01

The inverse data space provides a natural separation of primaries and surface-related multiples, as the surface multiples map onto the area around the origin while the primaries map elsewhere. However, the calculation of the inverse data is far from trivial as theory requires infinite time and offset recording. Furthermore regularization issues arise during inversion. We perform the inversion by minimizing the least-squares norm of the misfit function by constraining the $ell_1$ norm of the solution, being the inverse data space. In this way a sparse inversion approach is obtained. We show results on field data with an application to surface multiple removal.

Crystalline silicon films grown by pulsed dc magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Reinig, Peter; Fenske, Frank; Fuhs, Walther; Selle, Burkhardt [Hahn-Meitner-Institut Berlin, Abt. Silizium-Photovoltaik, Kekulestr. 5, D-12489 Berlin (Germany)

2002-04-01

Pulsed dc magnetron sputtering is used as a novel method for the deposition of crystalline silicon films on glass substrates. Hydrogen-free polycrystalline Si-films are deposited with high deposition rates at temperatures of 400-450 C and pulse frequencies f in the range 0-250 kHz. Strong preferential (100) orientation of the crystallites is observed with increasing f. High frequency and similarly high negative substrate bias cause an increase of the Ar content and an enhancement of structural disorder. Measurements of the transient floating potential suggest that the observed structural effects are related to bombardment of the growing film by Ar{sup +} ions of high energy.

Controlled formation of anatase and rutile TiO2 thin films by reactive magnetron sputtering

NARCIS (Netherlands)

Rafieian Boroujeni, Damon; Ogieglo, Wojciech; Savenije, Tom; Lammertink, Rob G.H.

2015-01-01

We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon annealing to

Nanoscale Cu{sub 2}O films: Radio-frequency magnetron sputtering and structural and optical studies

Energy Technology Data Exchange (ETDEWEB)

Kudryashov, D. A., E-mail: kudryashovda@apbau.ru; Gudovskikh, A. S. [Russian Academy of Sciences, St. Petersburg National Research Academic University — Nanotechnology Research and Education Center (Russian Federation); Babichev, A. V.; Filimonov, A. V. [Connector Optics LLC (Russian Federation); Mozharov, A. M. [Russian Academy of Sciences, St. Petersburg National Research Academic University — Nanotechnology Research and Education Center (Russian Federation); Agekyan, V. F.; Borisov, E. V.; Serov, A. Yu.; Filosofov, N. G. [St. Petersburg State University (Russian Federation)

2017-01-15

Nanoscale copper (I) oxide layers are formed by magnetron-assisted sputtering onto glassy and silicon substrates in an oxygen-free environment at room temperature, and the structural and optical properties of the layers are studied. It is shown that copper oxide formed on a silicon substrate exhibits a lower degree of disorder than that formed on a glassy substrate, which is supported by the observation of a higher intensity and a smaller half-width of reflections in the diffraction pattern. The highest intensity of reflections in the diffraction pattern is observed for Cu{sub 2}O films grown on silicon at a magnetron power of 150 W. The absorption and transmittance spectra of these Cu{sub 2}O films are in agreement with the well-known spectra of bulk crystals. In the Raman spectra of the films, phonons inherent in the crystal lattice of cubic Cu{sub 2}O crystals are identified.

Inverse hydrochemical models of aqueous extracts tests

Energy Technology Data Exchange (ETDEWEB)

Zheng, L.; Samper, J.; Montenegro, L.

2008-10-10

Aqueous extract test is a laboratory technique commonly used to measure the amount of soluble salts of a soil sample after adding a known mass of distilled water. Measured aqueous extract data have to be re-interpreted in order to infer porewater chemical composition of the sample because porewater chemistry changes significantly due to dilution and chemical reactions which take place during extraction. Here we present an inverse hydrochemical model to estimate porewater chemical composition from measured water content, aqueous extract, and mineralogical data. The model accounts for acid-base, redox, aqueous complexation, mineral dissolution/precipitation, gas dissolution/ex-solution, cation exchange and surface complexation reactions, of which are assumed to take place at local equilibrium. It has been solved with INVERSE-CORE{sup 2D} and been tested with bentonite samples taken from FEBEX (Full-scale Engineered Barrier EXperiment) in situ test. The inverse model reproduces most of the measured aqueous data except bicarbonate and provides an effective, flexible and comprehensive method to estimate porewater chemical composition of clays. Main uncertainties are related to kinetic calcite dissolution and variations in CO2(g) pressure.

The effect of brain hematoma location on volumetric inductive phase shift spectroscopy of the brain with circular and magnetron sensor coils: a numerical simulation study

International Nuclear Information System (INIS)

Rojas, R; González, C A; Rubinsky, B

2008-01-01

This numerical simulation study addressed the effects of the location of a discrete brain hematoma on the volumetric inductive phase shift of the brain measured with an induction circular sensor coil and an induction magnetron sensor coil. The theoretical study simulates the brain cavity as a circular sphere transversely centered with respect to the circular and magnetron sensor coils. As a case study for the effects of hematoma location, we employed similar size simulated spherical hematomas placed at three different positions from the center of the brain outward. A three-dimensional finite element analysis of the field equations in the frequency range from 100 kHz to 100 MHz revealed a substantial effect of hematoma location on the ability of both the circular and magnetron sensors to detect the hematomas. In particular it was found that there are frequencies, which may be related to resonance, at which the occurrence of the hematomas has no effect on the volumetric inductive phase shift of the brain. Furthermore it was found that the relative sensitivity of circular and magnetron sensor coils with respect to the occurrence of hematoma varies with the location of the hematoma

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Prosthodontics and Restorative Science, College of Dentistry, The Ohio State University, Columbus, OH (United States)

2014-12-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO{sub 3}){sub 2} + 3 mM NH{sub 4}H{sub 2}PO{sub 4}. Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings.

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

International Nuclear Information System (INIS)

Kim, Hyun-Ju; Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2014-01-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO 3 ) 2 + 3 mM NH 4 H 2 PO 4 . Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings

Reactive magnetron sputtering of Si-C-N films with controlled mechanical and optical properties

Czech Academy of Sciences Publication Activity Database

Vlček, J.; Kormunda, M.; Čížek, J.; Soukup, Z.; Peřina, Vratislav; Zemek, Josef

2003-01-01

Roč. 12, č. 8 (2003), s. 1287-1294 ISSN 0925-9635 R&D Projects: GA MŠk ME 203; GA MŠk OC 527.90 Institutional research plan: CEZ:MSM 235200002 Keywords : silicon-carbon-nitride films * magnetron co-sputtering Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.867, year: 2003

Effects of nitrogen ion implantation time on tungsten films deposited by DC magnetron sputtering on AISI 410 martensitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Malau, Viktor, E-mail: malau@ugm.ac.id; Ilman, Mochammad Noer, E-mail: noer-ilman@yahoo.com; Iswanto, Priyo Tri, E-mail: priyatri@yahoo.com; Jatisukamto, Gaguk, E-mail: gagukjtsk@yahoo.co.id [Mechanical and Industrial Engineering Department, Gadjah Mada University Jl. Grafika 2, Yogyakarta, 55281 (Indonesia)

2016-03-29

Nitrogen ion implantation time on tungsten thin film deposited on surface of AISI 410 steel has been performed. Tungsten thin film produced by dc magnetron sputtering method was deposited on AISI 410 martensitic stainless steel substrates, and then the nitrogen ions were implanted on tungsten thin film. The objective of this research is to investigate the effects of implantation deposition time on surface roughness, microhardness, specific wear and corrosion rate of nitrogen implanted on tungsten film. Magnetron sputtering process was performed by using plasma gas of argon (Ar) to bombardier tungsten target (W) in a vacuum chamber with a pressure of 7.6 x 10{sup −2} torr, a voltage of 300 V, a sputter current of 80 mA for sputtered time of 10 minutes. Nitrogen implantation on tungsten film was done with an initial pressure of 3x10{sup −6} mbar, a fluence of 2 x 10{sup 17} ions/cm{sup 2}, an energy of 100 keV and implantation deposition times of 0, 20, 30 and 40 minutes. The surface roughness, microhardness, specific wear and corrosion rate of the films were evaluated by surfcorder test, Vickers microhardness test, wear test and potentiostat (galvanostat) test respectively. The results show that the nitrogen ions implanted deposition time on tungsten film can modify the surface roughness, microhardness, specific wear and corrosion rate. The minimum surface roughness, specific wear and corrosion rate can be obtained for implantation time of 20 minutes and the maximum microhardness of the film is 329 VHN (Vickers Hardness Number) for implantation time of 30 minutes. The specific wear and corrosion rate of the film depend directly on the surface roughness.

Study on the preparation of boron-rich film by magnetron sputtering in oxygen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Pan, Zhangmin; Yang, Yiming; Huang, Jian; Ren, Bing; Yu, Hongze; Xu, Run; Ji, Huanhuan; Wang, Lin; Wang, Linjun, E-mail: ljwang@shu.edu.cn

2016-12-01

Highlights: • Boron ({sup 10}B) oxide films were successfully grown using RF magnetron sputtering. • Effects of oxygen partial pressure on the property of the films were studied. • Substrates were covered with B-rich film and film surface was covered with B{sub 2}O{sub 3}. • The growth mechanism of films in oxygen atmosphere was analyzed using XPS. - Abstract: In this paper, the growth of boron ({sup 10}B) oxide films on (1 0 0) silicon substrate were achieved by radio frequency (r.f.) magnetron sputtering under the different oxygen partial pressure with a target of boron and boron oxide. The structure and properties of deposited films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The results showed that the substrate was covered with boron-rich films tightly and the surface of films was covered with B{sub 2}O{sub 3}. And the growth mechanism of boron-rich film in oxygen atmosphere was also analyzed.

Microstructure and electrical properties of bismuth and bismuth oxide deposited by magnetron sputtering UBM

International Nuclear Information System (INIS)

Otalora B, D. M.; Dussan, A.; Olaya F, J. J.

2015-01-01

In this work, bismuth (Bi) and bismuth oxide (Bi 2 O 3 ) thin films were prepared, at room temperature, by Sputtering Unbalanced Magnetron (UBM - Unbalance Magnetron) technique under glass substrates. Microstructural and electrical properties of the samples were studied by X-ray diffraction (XRD) and System for Measuring Physical Properties - PPMS (Physical Property Measurement System). Dark resistivity of the material was measured for a temperature range between 100 and 400 K. From the XRD measurements it was observed a polycrystalline character of the Bi associated to the presence of phases above the main peak, 2θ = 26.42 grades and a growth governed by a rhombohedral structure. Crystal parameters were obtained for both compounds, Bi and Bi 2 O 3 . From the analysis of the spectra of the conductivity as a function of temperature, it was established that the transport mechanism that governs the region of high temperature (T>300 K) is thermally activated carriers. From conductivity measurements the activation energies were obtained of 0.0094 eV and 0.015 eV for Bi 2 O 3 and Bi, respectively. (Author)

Microstructural control of TiC/a-C nanocomposite coatings with pulsed magnetron sputtering

International Nuclear Information System (INIS)

Pei, Y.T.; Chen, C.Q.; Shaha, K.P.; De Hosson, J.Th.M.; Bradley, J.W.; Voronin, S.A.; Cada, M.

2008-01-01

In this paper, we report some striking results on the microstructural control of TiC/a-C nanocomposite coatings with pulsed direct current (DC) magnetron sputtering. The interface morphology and microstructure evolution as a function of pulse frequency and duty cycle were scrutinized using atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy techniques. It is shown that, with increasing pulse frequency, the nanocomposite coatings exhibit evolutions in morphology of the growing interface from rough to smooth and in the microstructure from strongly columnar to fully columnar-free. In addition, the smoothly growing interface favors the formation of a tailor-made multilayered nanocomposite structure. The fundamental mechanisms are analyzed with the assistance of plasma diagnostic experiments. Ion mass/energy spectrometry measurements reveal that, depending on the frequency and duty cycle of DC pulses, pulsing of the magnetrons can control the flux and energy distribution of Ar + ions over a very broad range for concurrent impingement on the growing interface of deposited coatings, in comparison with DC sputtering. The significantly enhanced energy flux density is thought to be responsible for the 'adatom transfer' in interface smoothening and thus the restraint of columnar growth

Investigation of the possible technological use of magnetron-synthetic coverings on the basis of niobium nitridium to manufacture high conductivity windings during the generation of power magnetic fields

International Nuclear Information System (INIS)

Kadyrzhanov, K.; Zhetbaev, A.; Tuleushev, A.; Penkov, F.; Lisitsin, V.; Kim, S.; Tuleushev, Yu.; Turkebaev, T.; Borisenko, A.; Gorlachev, I.; Platov, A.; Lisuchin, S.; Skoz, E.; Zhukov, V.; Guliykin, Yu.; Chavalinsky, Yu.

1996-01-01

The main objective. The objective of this project is to investigate the possibilities for technological use of niobium nitride-based magnetron synthesized coatings for the purpose of manufacture of superconducting tape windings when generating strong magnetic fields for NMR-tomographs and commercial magnets. Background. Niobium nitride can be produced by sputtering as a continuous coating directly on the surface of a substrate made of a normal conductor, e.g. a copper or aluminium thin tape, by well-known techniques of plasma-chemical synthesis, using magnetron procedure (d.c. magnetron), allowing al synthesis, using magnetron procedure (d.c. magnetron), allowing to solve some difficult problems of superconductor manufacture by means of plastic deformation. For example, risk of break of a superconducting thread will no longer arises and the procedure of control for heat removal and relation between the thickness of superconducting and normal components will be made much easier, and, in turn, this enables to enhance stability of superconductivity and to prevent flux quench. Methodology. The group of eleven specialists from NNC RK will be occupied in the magnetron synthesis of niobium nitride coatings of copper and aluminum foils (five persons) and in its X-ray, nuclear-physical and electron microscopic analysis (six persons). The group of six specialists from the ULBA plant will be occupied in determination of the critical parameters of belt samples with niobium nitride coatings produced by Inst. of Nuclear Physics' specialists. Multi-purpose research test benches for determination of superconductor critical parameters that are available at the ULBA enables to test different types superconductor characteristics, including film ones, in magnetic fields up to 11 T at helium temperatures. Expected Results. As the result of the project execution complete evaluation concerning technical reasoning for magnetron ways of coating synthesis of niobium nitride when

Microstructure of ZnO thin films deposited by high power impulse magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Reed, A.N., E-mail: amber.reed.5@us.af.mil [Materials and Manufacturing Directorate, Air Force Research Laboratory, 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433 (United States); Department of Chemical and Materials Engineering, University of Dayton, Dayton, OH 45469 (United States); Shamberger, P.J. [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States); Hu, J.J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433 (United States); University of Dayton Research Institute, University of Dayton, Dayton, OH 45469 (United States); Muratore, C. [Department of Chemical and Materials Engineering, University of Dayton, Dayton, OH 45469 (United States); Bultman, J.E. [Materials and Manufacturing Directorate, Air Force Research Laboratory, 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433 (United States); University of Dayton Research Institute, University of Dayton, Dayton, OH 45469 (United States); Voevodin, A.A., E-mail: andrey.voevodin@us.af.mil [Materials and Manufacturing Directorate, Air Force Research Laboratory, 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433 (United States)

2015-03-31

High power impulse magnetron sputtering was used to deposit thin (~ 100 nm) zinc oxide (ZnO) films from a ceramic ZnO target onto substrates heated to 150 °C. The resulting films had strong crystallinity, highly aligned (002) texture and low surface roughness (root mean square roughness less than 10 nm), as determined by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and atomic force spectroscopy measurements. Deposition pressure and target–substrate distance had the greatest effect on film microstructure. The degree of alignment in the films was strongly dependent on the gas pressure. Deposition at pressures less than 0.93 Pa resulted in a bimodal distribution of grain sizes. An initial growth layer with preferred orientations (101) and (002) parallel to the interface was observed at the film–substrate interface under all conditions examined here; the extent of that competitive region was dependent on growth conditions. Time-resolved current measurements of the target and ion energy distributions, determined using energy resolved mass spectrometry, were correlated to film microstructure in order to investigate the effect of plasma conditions on film nucleation and growth. - Highlights: • Low temperature growth of nanocrystalline zinc oxide (ZnO) films. • ZnO films had a highly (002) textured, smooth, dense microstructure. • Dominant (002) orientation of films was pressure dependent. • Interfacial (101)/(002) mixed orientation layer controlled by substrate location.

Zn{sub x}Zr{sub y}O{sub z} thin films grown by DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Sanchez, O. [Instituto de Ciencia de Materiales de Madrid (CSIC), Madrid (Spain); Hernandez-Velez, M. [Departamento de Fisica Aplicada, Universidad Autonoma de Madrid (Spain)

2017-10-15

The structural and optical properties of thin films deposited by DC reactive magnetron co-sputtering using Zn and Zr targets in argon and oxygen gas mixtures at room temperature are reported. The power applied to the Zr cathode was kept constant, while that applied to the Zn cathode was varied between 0 and 150 W to produce very different Zn{sub x}Zr{sub y}O{sub z} ternary compounds with Zn/Zr atomic ratios in the range of 0.1-10. The composition, crystalline structure, and optical properties of the samples were determined by EDX, XRD, FTIR, and UV-visible spectroscopies. The grown films are polycrystalline, and the preferred crystallographic orientation depends on the Zn atomic concentration in the film. The optical transmission in the UV-visible range is approximately 80% in all cases, and as the Zn atomic content increases, the absorption edge shifts to longer wavelengths. The optical band gap, E{sub g}, shifted from 5.5 to 3.5 eV when the Zn/Zr atomic ratio was increased. The results indicate the potential use of these materials in optoelectronic applications. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Metal-oxide-junction, triple point cathodes in a relativistic magnetron

International Nuclear Information System (INIS)

Jordan, N. M.; Gilgenbach, R. M.; Hoff, B. W.; Lau, Y. Y.

2008-01-01

Triple point, defined as the junction of metal, dielectric, and vacuum, is the location where electron emission is favored in the presence of a sufficiently strong electric field. To exploit triple point emission, metal-oxide-junction (MOJ) cathodes consisting of dielectric ''islands'' over stainless steel substrates have been fabricated. The two dielectrics used are hafnium oxide (HfO x ) for its high dielectric constant and magnesium oxide (MgO) for its high secondary electron emission coefficient. The coatings are deposited by ablation-plasma-ion lithography using a KrF laser (0-600 mJ at 248 nm) and fluence ranging from 3 to 40 J/cm 2 . Composition and morphology of deposited films are analyzed by scanning electron microscopy coupled with x-ray energy dispersive spectroscopy, as well as x-ray diffraction. Cathodes are tested on the Michigan Electron Long-Beam Accelerator with a relativistic magnetron, at parameters V=-300 kV, I=1-15 kA, and pulse lengths of 0.3-0.5 μs. Six variations of the MOJ cathode are tested, and are compared against five baseline cases. It is found that particulate formed during the ablation process improves the electron emission properties of the cathodes by forming additional triple points. Due to extensive electron back bombardment during magnetron operation, secondary electron emission also may play a significant role. Cathodes exhibit increases in current densities of up to 80 A/cm 2 , and up to 15% improvement in current start up time, as compared to polished stainless steel cathodes

A comparison of plasma in laser and hybrid laser-magnetron SiC deposition systems

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Lančok, Ján; Jelínek, Miroslav

2007-01-01

Roč. 4, - (2007), S1017-S1021 ISSN 1612-8850 R&D Projects: GA AV ČR KJB1010417; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : laser ablation * magnetron sputtering * optical emission spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.132, year: 2007

Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

Directory of Open Access Journals (Sweden)

C. B. Alden

2018-03-01

Full Text Available Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m, integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB. The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model–data mismatch. It is also tested with field observations of (1 a non-leaking source location and (2 a source location where a controlled emission of 3.1  ×  10−5 kg s−1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests. The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability and measurement uncertainty of 5 ppb (1σ, when

Inverse modeling for the determination of hydrogeological parameters of a two-phase system

International Nuclear Information System (INIS)

Finsterle, S.

1993-02-01

Investigations related to the disposal of radioactive wastes in Switzerland consider formations containing natural gas as potential rocks for a repository. Moreover, gas generation in the repository itself may lead to an unsaturated zone of significant extent and impact on the system's performance. The site characterization procedure requires the estimation of hydraulic properties being used as input parameters for a two-phase two-component numerical simulator. In this study, estimates of gas-related formation parameters are obtained by inverse modeling. Based on discrete observations of the system's state, model parameters can be estimated within the framework of a given conceptual model by means of optimization techniques. This study presents the theoretical background that related field data to the model parameters. A parameter estimation procedure is proposed and implemented in a computer code for automatic model calibration. This tool allows identification of key parameters affecting flow of water and gas in porous media. The inverse modeling approach is verified using data from a synthetic laboratory experiment. In addition, the Gas test performed at the Grimsel Test Site is analyzed in order to demonstrate the applicability of the proposed procedure when used with data from a real geologic environment. Estimation of hydrogeologic parameters by automatic model calibration improves the understanding of the two-phase flow processes and therefore increases the reliability of the subsequent simulation runs. (author) figs., tabs., refs

The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

2015-05-01

Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films.

The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

International Nuclear Information System (INIS)

Lisco, F.; Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

2015-01-01

Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films

Growth behavior of rat bone marrow cells on RF magnetron sputtered hydroxyapatite and dicalcium pyrophosphate coatings.

NARCIS (Netherlands)

Yan, Y.; Wolke, J.G.C.; Ruijter, A. De; Yubao, L.; Jansen, J.A.

2006-01-01

The aim of this study was to evaluate the osteogenic properties of magnetron sputtered dicalcium pyrophaosphate (DCPP) and hydroxylapatite (HA) coatings. Therefore, DCPP and HA coatings were deposited on grit-blasted titanium discs. The substrates were used as-prepared or received an additional heat

Antibacterial properties of nano-silver coated PEEK prepared through magnetron sputtering.

Science.gov (United States)

Liu, Xiuju; Gan, Kang; Liu, Hong; Song, Xiaoqing; Chen, Tianjie; Liu, Chenchen

2017-09-01

We aimed to investigate the cytotoxicity and antibacterial properties of nano-silver-coated polyetheretherketone (PEEK) produced through magnetron sputtering and provide a theoretical basis for its use in clinical applications. The surfaces of PEEKs were coated with nano-silver at varying thicknesses (3, 6, 9, and 12nm) through magnetron sputtering technology. The resulting coated PEEK samples were classified into the following groups according to the thickness of the nano-silver coating: PEEK-3 (3nm), PEEK-6 (6nm), PEEK-9 (9nm), PEEK-12 (12nm), and PEEK control group. The surface microstructure and composition of each sample were observed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy dispersive spectrum (EDS) analysis. The water contact angle of each sample was then measured by contact angle meters. A cell counting kit (CCK-8) was used to analyze the cytotoxicity of the mouse fibroblast cells (L929) in the coated groups (n=5) and group test samples (n=6), negative control (polyethylene, PE) (n=6), and positive control group (phenol) (n=6). The antibacterial properties of the samples were tested by co-culturing Streptococcus mutans and Straphylococcus aureus. The bacteria that adhered to the surface of samples were observed by SEM. The antibacterial adhesion ability of each sample was then evaluated. SEM and AFM analysis results showed that the surfaces of control group samples were smooth but compact. Homogeneous silver nano-particles (AgNPs) and nano-silver coating were uniformly distributed on the surface of the coated group samples. Compared with the control samples, the nano-silver coated samples had a significant increase in surface roughness (Pnano-silver coating increased. EDS analysis showed that not only C and O but also Ag were present on the surface of the coated samples. Moreover, the water contact angle of modified samples significantly increased after nano-silver coating modification (Pnano-silver coating can

Advanced TiC/a-C: H nanocomposite coatings deposited by magnetron sputtering

OpenAIRE

Pei, Y.T.; Galvan, D.; Hosson, J.Th.M. De; Strondl, C.

2006-01-01

TiC/a-C:H nanocomposite coatings have been deposited by magnetron Sputtering. They consist of 2-5 nm TiC nanocrystallites embedded in the amorphous hydrocarbon (a-C:H) matrix. A transition from a Columnar to a glassy microstructure has been observed in the nanocomposite coatings with increasing substrate bias or carbon content. Micro-cracks induced by nanoindentation or wear tests readily propagate through the column boundaries whereas the coatings without a columnar inicrostructure exhibit s...

Smoothing of ZnO films by gas cluster ion beam

International Nuclear Information System (INIS)

Chen, H.; Liu, S.W.; Wang, X.M.; Iliev, M.N.; Chen, C.L.; Yu, X.K.; Liu, J.R.; Ma, K.; Chu, W.K.

2005-01-01

Planarization of wide-band-gap semiconductor ZnO surface is crucial for thin-film device performance. In this study, the rough initial surfaces of ZnO films deposited by r.f. magnetron sputtering on Si substrates were smoothed by gas cluster ion beams. AFM measurements show that the average surface roughness (R a ) of the ZnO films could be reduced considerably from 16.1 nm to 0.9 nm. Raman spectroscopy was used to monitor the structure of both the as-grown and the smoothed ZnO films. Rutherford back-scattering in combination with channeling effect was used to study the damage production induced by the cluster bombardment

Deposition of thin titanium-copper films with antimicrobial effect by advanced magnetron sputtering methods

Czech Academy of Sciences Publication Activity Database

Straňák, V.; Wulff, H.; Rebl, H.; Zietz, C.; Arndt, K.; Bogdanowicz, R.; Nebe, B.; Bader, R.; Podbielski, A.; Hubička, Zdeněk; Hippler, R.

2011-01-01

Roč. 31, č. 7 (2011), s. 1512-1519 ISSN 0928-4931 R&D Projects: GA ČR(CZ) GAP205/11/0386; GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100520 Keywords : implant coating * titanium-copper film * pulsed magnetron sputtering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.686, year: 2011

Surface properties of calcium and magnesium oxide nanopowders grafted with unsaturated carboxylic acids studied with inverse gas chromatography.

Science.gov (United States)

Maciejewska, Magdalena; Krzywania-Kaliszewska, Alicja; Zaborski, Marian

2012-09-28

Inverse gas chromatography (IGC) was applied at infinite dilution to evaluate the surface properties of calcium and magnesium oxide nanoparticles and the effect of surface grafted unsaturated carboxylic acid on the nanopowder donor-acceptor characteristics. The dispersive components (γ(s)(D)) of the free energy of the nanopowders were determined by Gray's method, whereas their tendency to undergo specific interactions was estimated based on the electron donor-acceptor approach presented by Papirer. The calcium and magnesium oxide nanoparticles exhibited high surface energies (79 mJ/m² and 74 mJ/m², respectively). Modification of nanopowders with unsaturated carboxylic acids decreased their specific adsorption energy. The lowest value of γ(s)(D) was determined for nanopowders grafted with undecylenic acid, approximately 55 mJ/m². The specific interactions were characterised by the molar free energy (ΔG(A)(SP)) and molar enthalpy (ΔH(A)(SP)) of adsorption as well as the donor and acceptor interaction parameters (K(A), K(D)). Copyright © 2012 Elsevier B.V. All rights reserved.

Studies of population inversion and gains for xuv laser development in a recombining plasma column

International Nuclear Information System (INIS)

Milchberg, H.M.

1985-01-01

An experimental study is presented of population inversions and gains in CO 2 laser produced plasmas in a number of different solid and gas targets, with and without the presence of a magnetic field. Population inversions and gains were measured in hydrogenic carbon, CVI, and in the Li-like sequence CIV, OVI, FVII, and NeVIII. The Li-like species were easily produced in gas targets and, in general, 4d-3d population inversions were seen to increase with a combination of higher target pressure and the presence of an external magnetic field. Ratios of the 4d-3d sublevel populations ranged up to approx.10, for OVI. Inversions in CIV and FVII, in cases where solid targets were used, were less sensitive to the presence of the magnetic field. Gains in the CVI 182.17 A (3-2) line were measured using solid carbon targets, and increased in the presence of a magnetic field. The effect of placing aluminum blades near the target, for plasma cooling and faster recombination, was inconclusive. In general, gains determined by measuring an on-axis enhancement of the 182.17 A line were consistent with absolute measurements of CVI excitation-level populations. Gains of 2-4 cm -1 were measured. Axially oriented carbon-fiber targets were irradiated by the CO 2 laser, and it was found that population inversions and gain resulted only when there was no magnetic field present

Numerical investigation of gas separation in T-junction

Science.gov (United States)

Pao, William; Hashim, Fakhruldin M.; Ming, Low Huei

2015-05-01

T-junctions are commonly used in distributing two-phase flow by piping networks especially in oil and gas industries. Understanding the behavior of two-phase flow through a T-junction is very important as it has significant effect on the operation, maintenance and efficiency of the components downstream from the junction. The objective of this paper is to determine the effect of ratio of side arm to main arm diameters, initial inlet gas saturation and gas density variation on passive separation performance in T-junction. Via computational fluid dynamics tool, preliminary investigation found that separation efficiency is proportional to diameter ratio in between 0.5-0.75. Beyond diameter ratio 0.75, there is a flattening of separation efficiency. The change of fraction of gas taken off is inversely proportional to initial inlet gas saturation and the trend is almost inversely linear for diameter ratio 0.5. Beyond that, the relationship between initial inlet gas saturation and separation efficiency exhibits mild non-linearity behavior. For diameter ratios 0.75-1.0, the fraction of gas taken off is almost similar as far as the initial gas saturation is concerned. Gas density affects phase separation efficiency when the initial gas saturation is low. Interestingly, the effects of the inlet flow velocity and gravity distribution is almost negligible relative to the mass split ratio, side to main arm diameter ratio, initial gas saturation and density differential.

The URban Greenhouse gas Emissions assessment through inverse modeling (URGE) project: a pilot study in the Oslo area

Science.gov (United States)

Pisso, I. J.; Lopez-Aparicio, S.; Schneider, P.; Schmidbauer, N.; Vogt, M.

2017-12-01

Norway has set the target of cutting greenhouse gas (GHG) emissions by at least 40% compared to 1990 levels by 2030. This goal will require the implementation of policy measures aiming at strong reductions of GHGs emissions, especially in the urban environment. The implementation of urban policy measures is still a challenging task and it requires control and verification for success. The URGE project aims at assessing the emission flux of GHGs including comprehensive uncertainty estimates based on inverse transport modelling techniques and optimized use of measurements. The final goal is to establish a coherent and consistent GHG urban emission inventory. This will be carried out in a case study in Oslo (Norway), where CO2 will be the priority compound. The overall outcome of the project will provide support in the development of strategies to effectively reduce GHG emissions in the urban environment. The overall goal will be reached through establishing the baseline urban CO2 emission inventory for Oslo; determining the optimal measurement locations based on transport modelling (with flexpart-wrf); designing and carrying out a pilot measurement campaign of the CO2-rich air downwind of the city plume combining state-of-the-art instruments (Picarro) and small sensors; assessing the feasibility of determining the background concentration surrounding the city with satellite measurements (OCO2); and providing optimised estimates of the emissions and their uncertainties via inverse modelling (source-receptor relationship). One of our main interests is the interoperability and exchange of information with similar activities in other urban areas. We will present the overall project and the preliminary results of the network design. We will discuss the data exchange formats, the algorithms and data structures that could be used for results and methodology intercomparisons as well as the suitability to apply the same techniques to other atmospheric compounds.

Deposition of thin films by magnetron sputtering molybdenum in samples of pure copper; Deposicao de filmes finos de molibdenio por magnetron sputtering em amostra de cobre puro

Energy Technology Data Exchange (ETDEWEB)

Ferreira, N.M.; Almeida, E.O. de; Alves Junior, C. [Universidade Federal do Rio Grande do Norte, Campus Universitario Lagoa Nova, PPGCEM - Natal, RN (Brazil); Lourenco, J.M. [Instituto Federal de Educacao, Ciencias e Tecnologia do Rio Grande do Norte (IFRN), Natal, RN (Brazil)

2010-07-01

The deposition surface is a process of thermochemical treatment, which involves the deposition of a thin film usually about one to two microns on a metallic substrate, which constitutes one of the most important surface engineering techniques. The plasma deposition process with the configuration of magnetron sputtering it is removing material from a solid surface (target) through the impact of energetic particles from plasma. The aim of this study is to characterize the microstructure of the material under study using the techniques of optical microscopy and scanning electron microscopy. (author)

Study of working pressure on the optoelectrical properties of Al–Y codoped ZnO thin-film deposited using DC magnetron sputtering for solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Hsu, Feng-Hao [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No. 1, Dasyue Road, East District, Tainan City 701, Taiwan (China); Wang, Na-Fu; Tsai, Yu-Zen; Chuang, Ming-Chieh; Cheng, Yu-Song [Department of Electronic Engineering, Cheng Shiu University, 840 Chengcing Road, Niaosong District, Kaohsiung City 833, Taiwan (China); Houng, Mau-Phon, E-mail: mphoung@eembox.ncku.edu.tw [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No. 1, Dasyue Road, East District, Tainan City 701, Taiwan (China)

2013-09-01

Low cost transparent conductive Al–Y codoped ZnO (AZOY) thin-films were prepared on a glass substrate using a DC magnetron sputtering technique with various working pressures in the range of 5–13 mTorr. The relationship among the structural, electrical, and optical properties of sputtered AZOY films was studied as a function of working pressure. The XRD measurements show that the crystallinity of the films degraded as the working gas pressure increased. The AZOY thin-film deposited at a working pressure of 5 mTorr exhibited the lowest electrical resistivity of 4.3 × 10{sup −4} Ω cm, carrier mobility of 30 cm{sup 2}/V s, highest carrier concentration of 4.9 × 10{sup 20} cm{sup −3}, and high transmittance in the visible region (400–800 nm) of approximately 90%. Compared with Al doped ZnO (AZO) thin-films deposited using DC or RF magnetron sputtering methods, a high carrier mobility was observed in our AZOY thin-films. This result can be used to effectively decrease the absorption of near infrared-rays in solar cell applications. The mechanisms are attributed to the larger transition energy between Ar atoms and sputtering particles and the size compensation of the dopants. Finally, the optimal quality AZOY thin-film was used as an emitter layer (or window layer) to form AZOY/n-Si heterojunction solar cells, which exhibited a stable conversion efficiency (η) of 9.4% under an AM1.5 illumination condition.

Fabrication and characterization of He-charged ODS-FeCrNi films deposited by a radio-frequency plasma magnetron sputtering technique

Science.gov (United States)

Song, Liang; Wang, Xianping; Wang, Le; Zhang, Ying; Liu, Wang; Jiang, Weibing; Zhang, Tao; Fang, Qianfeng; Liu, Changsong

2017-04-01

He-charged oxide dispersion strengthened (ODS) FeCrNi films were prepared by a radio-frequency (RF) plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C. As a comparison, He-charged FeCrNi films were also fabricated at the same conditions through direct current (DC) plasma magnetron sputtering. The doping of He atoms and Y2O3 in the FeCrNi films was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method, respectively. Inductive coupled plasma (ICP) and x-ray photoelectron spectroscopy (XPS) analysis confirmed the existence of Y2O3 in FeCrNi films, and Y2O3 content hardly changed with sputtering He/Ar ratio. Cross-sectional scanning electron microscopy (SEM) shows that the FeCrNi films were composed of dense columnar nanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio. Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio, while the dispersion of Y2O3 apparently increased the hardness of the films. Elastic recoil detection (ERD) showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts (˜17 at.%). Compared with the minimal change of He level with depth in DC-sputtered films, the He amount decreases gradually in depth in the RF-sputtered films. The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.

Parallelization of simulation code for liquid-gas model of lattice-gas fluid

International Nuclear Information System (INIS)

Kawai, Wataru; Ebihara, Kenichi; Kume, Etsuo; Watanabe, Tadashi

2000-03-01

A simulation code for hydrodynamical phenomena which is based on the liquid-gas model of lattice-gas fluid is parallelized by using MPI (Message Passing Interface) library. The parallelized code can be applied to the larger size of the simulations than the non-parallelized code. The calculation times of the parallelized code on VPP500 (Vector-Parallel super computer with dispersed memory units), AP3000 (Scalar-parallel server with dispersed memory units), and a workstation cluster decreased in inverse proportion to the number of processors. (author)

Niobium films produced by magnetron sputtering using an Ar-He mixture as discharge gas

CERN Document Server

Schucan, G M; Calatroni, Sergio

1995-01-01

Superconducting RF accelerating cavities have been produced at CERN by sputter-coating, with a thin niobium layer, cavities made of copper. In the present work, the discharge behaviour and niobium film properties have been investigated when part of the argon sputtering gas is replaced with helium. Helium is chosen because of its low mass, which reduces the energy lost by the niobium atoms colliding with the sputter gas atoms. The higher niobium atom energy should lead to higher adatom mobility on the substrate and, hence, to a larger grain size, a feature which is highly desirable to reduce the cavity surface resistance. It has been found that helium addition effectively helps to maintain the discharge at considerably lower argon pressures, via metastable-neutral ionisation and high secondary electron yield. However, a large amount of helium is trapped in the film, amount which is proportional to the helium partial pressure during the discharge, resulting in a reduction of both Residual Resistivity Ratio and ...

Structural evolution and growth mechanisms of RF-magnetron sputter-deposited hydroxyapatite thin films on the basis of unified principles

Science.gov (United States)

Ivanova, Anna A.; Surmeneva, Maria A.; Surmenev, Roman A.; Depla, Diederik

2017-12-01

The structural features of RF-magnetron sputter-deposited hydroxyapatite (HA) coatings are investigated in order to reveal the effect of the working gas composition and the sample position of the substrate relative to the target erosion zone. The film properties were observed to change as a result of bombardment with energetic ions. XRD analysis of the coated substrates indicates that with the increase of the ion-to-atom ratio, the fiber texture changes from a mixed (11 2 bar 2) + (0002) over (0002) orientation, finally reaching a (30 3 bar 0) out-of-plane orientation at high ion-to-atom ratios. TEM reveals that the microstructure of the HA coating consists of columnar grains and differs with the coating texture. The contribution of Ji/Ja to the development of microstructure and texture of the HA coating is schematically represented and discussed. The obtained results may contribute substantially to the progress of research into the development of HA coatings with tailored properties, and these coatings may be applied on the surfaces of metal implants used in bone surgery.

Effect of annealing on refractive indices of radio-frequency magnetron sputtered waveguiding zinc oxide films on glass

International Nuclear Information System (INIS)

Mehan, Navina; Gupta, Vinay; Sreenivas, Kondepudy; Mansingh, Abhai

2004-01-01

The effects of annealing and gas composition on the refractive indices of zinc oxide films were studied in light of the structural properties. ZnO films (1 μm) were deposited by rf magnetron sputtering in different oxygen:argon mixtures on glass and annealed at 380 deg. C in air, at different times. Waveguide modes were excited in the films by prism coupling using a He-Ne laser. The estimated values of the extraordinary and ordinary refractive indices of the films, which were close to the corresponding bulk values (n e =2.006, n o =1.990), initially decreased with annealing time and later increased before becoming constant with further annealing. The variation in refractive indices was explained on the basis of contribution from both packing density p and lattice constant c of the films. The initial decrease in refractive indices was attributed to the observed lattice contraction, and the latter increase was explained in terms of the increase in packing density (p) of the films on annealing. A relation is proposed to estimate the refractive indices of films, which have the lattice constant c different from the bulk value

Surface functionalization of nanostructured LaB{sub 6}-coated Poly Trilobal fabric by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Wu, Yan, E-mail: wuyanchn@hotmail.com [Mechanical and Electrical Engineering Branch, Jiaxing Nanyang Polytechnic Institute, Jiaxing 314003 (China); Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Zhang, Lin, E-mail: zhanglin2007@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Min, Guanghui, E-mail: ghmin@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Yu, Huashun; Gao, Binghuan; Liu, Huihui; Xing, Shilong; Pang, Tao [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China)

2016-10-30

Highlights: • Nanostructured LaB{sub 6} films were deposited on flexible textile substrates by dc magnetron sputtering. • The pronounced influence of the working pressure on the morphologies and optical properties of LaB{sub 6} films has been revealed. • The concept of Ultraviolet Protection Factor (UPF) was employed and LaB{sub 6}-coated PET textiles with ultraviolet protection ability were obtained. - Abstract: Nanostructured LaB{sub 6} films were deposited on flexible Poly Trilobal substrates (PET textiles) through direct current magnetron sputtering in order to broaden its applications and realize surface functionalization of polyester fabrics. Characterizations and performances were investigated by employing a scanning electron microscope (SEM), Fourier transformation infrared spectroscopy (FT-IR) and ultraviolet-visible (UV–vis) spectrophotometer. Ultraviolet Protection Factor (UPF) conducted by the integral conversion was employed to measure the ultraviolet protection ability. As expected, the growth of LaB{sub 6} film depending on the pressure variation enhanced UV-blocking ability (UPF rating at 30.17) and absorption intensity of the textiles.

Preparation of single-crystal TiC (111) by radio frequency magnetron sputtering at low temperature

International Nuclear Information System (INIS)

Qi, Q.; Zhang, W.Z.; Shi, L.Q.; Zhang, W.Y.; Zhang, W.; Zhang, B.

2012-01-01

Single-crystal films of TiC (111) have been synthesized at room temperature on Al 2 O 3 (0001) substrates by radio frequency magnetron sputtering using a compound Ti–C target. The substrate temperature and bias were varied to explore the influence of deposition parameters on the crystal structure. Both Al 2 O 3 (0001) and Si (100) substrates were used for epitaxial growth of TiC films. A series of characterizations of TiC films were carried out, including Rutherford backscattering spectroscopy, X-ray diffraction, Raman and X-ray photoelectron spectroscopy. Single-crystal films of TiC (111) on the Al 2 O 3 (0001) were demonstrated. - Highlights: ► Single-crystal films of TiC (111) have been synthesized by RF magnetron sputtering. ► Both temperature and bias affect greatly the TiC crystal structure. ► Al 2 O 3 substrate is much better than Si substrate for TiC epitaxial growth. ► TiC (111) epitaxial film can be grown on Al 2 O 3 (0001) at room temperature.

Tribological properties, corrosion resistance and biocompatibility of magnetron sputtered titanium-amorphous carbon coatings

Science.gov (United States)

Dhandapani, Vishnu Shankar; Subbiah, Ramesh; Thangavel, Elangovan; Arumugam, Madhankumar; Park, Kwideok; Gasem, Zuhair M.; Veeraragavan, Veeravazhuthi; Kim, Dae-Eun

2016-05-01

Amorphous carbon incorporated with titanium (a-C:Ti) was coated on 316L stainless steel (SS) by magnetron sputtering technique to attain superior tribological properties, corrosion resistance and biocompatibility. The morphology, topography and functional groups of the nanostructured a-C:Ti coatings in various concentrations were analyzed using atomic force microscopy (AFM), Raman, X-Ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Raman and XPS analyses confirmed the increase in sp2 bonds with increasing titanium content in the a-C matrix. TEM analysis confirmed the composite nature of the coating and the presence of nanostructured TiC for Ti content of 2.33 at.%. This coating showed superior tribological properties compared to the other a-C:Ti coatings. Furthermore, electrochemical corrosion studies were performed against stimulated body fluid medium in which all the a-C:Ti coatings showed improved corrosion resistance than the pure a-C coating. Preosteoblasts proliferation and viability on the specimens were tested and the results showed that a-C:Ti coatings with relatively high Ti (3.77 at.%) content had better biocompatibility. Based on the results of this work, highly durable coatings with good biocompatibility could be achieved by incorporation of optimum amount of Ti in a-C coatings deposited on SS by magnetron sputtering technique.

Micro-seismic waveform matching inversion based on gravitational search algorithm and parallel computation

Science.gov (United States)

Jiang, Y.; Xing, H. L.

2016-12-01

Micro-seismic events induced by water injection, mining activity or oil/gas extraction are quite informative, the interpretation of which can be applied for the reconstruction of underground stress and monitoring of hydraulic fracturing progress in oil/gas reservoirs. The source characterises and locations are crucial parameters that required for these purposes, which can be obtained through the waveform matching inversion (WMI) method. Therefore it is imperative to develop a WMI algorithm with high accuracy and convergence speed. Heuristic algorithm, as a category of nonlinear method, possesses a very high convergence speed and good capacity to overcome local minimal values, and has been well applied for many areas (e.g. image processing, artificial intelligence). However, its effectiveness for micro-seismic WMI is still poorly investigated; very few literatures exits that addressing this subject. In this research an advanced heuristic algorithm, gravitational search algorithm (GSA) , is proposed to estimate the focal mechanism (angle of strike, dip and rake) and source locations in three dimension. Unlike traditional inversion methods, the heuristic algorithm inversion does not require the approximation of green function. The method directly interacts with a CPU parallelized finite difference forward modelling engine, and updating the model parameters under GSA criterions. The effectiveness of this method is tested with synthetic data form a multi-layered elastic model; the results indicate GSA can be well applied on WMI and has its unique advantages. Keywords: Micro-seismicity, Waveform matching inversion, gravitational search algorithm, parallel computation

RF magnetron sputtered La3+-modified PZT thin films: Perovskite phase stabilization and properties

International Nuclear Information System (INIS)

Singh, Ravindra; Goel, T.C.; Chandra, Sudhir

2008-01-01

In this work, we report the preparation of lanthanum-modified lead zirconate titanate (PLZT) thin films in pure perovskite phase by RF magnetron sputtering. Various deposition parameters such as target-to-substrate spacing, sputtering gas composition, deposition temperature, post-deposition annealing temperature and time have been optimized to obtain PLZT films in pure perovskite phase. The films prepared in pure argon at 100 W RF power without external substrate heating exhibit pure perovskite phase after rapid thermal annealing (RTA) at 700 deg. C for 5 min. The film prepared at 225 deg. C substrate temperature also exhibits pure perovskite phase after RTA at 700 deg. C for 2 min. SIMS depth profile performed on one of the pure perovskite films (RTA at 700 deg. C for 5 min) shows very good stoichiometric uniformity of all elements of PLZT. The surface morphology of the films was examined using SEM and AFM. The dielectric, ferroelectric and electrical properties of the pure perovskite films were also investigated in detail. The remanent polarization for the films annealed at 700 deg. C for 5 and 2 min were found to be 15 and 13.5 μC cm -2 , respectively. Both the films have high DC resistivity of the order of 10 11 Ω cm at the electric field of ∼80 kV cm -1

Angle-domain inverse scattering migration/inversion in isotropic media

Science.gov (United States)

Li, Wuqun; Mao, Weijian; Li, Xuelei; Ouyang, Wei; Liang, Quan

2018-07-01

The classical seismic asymptotic inversion can be transformed into a problem of inversion of generalized Radon transform (GRT). In such methods, the combined parameters are linearly attached to the scattered wave-field by Born approximation and recovered by applying an inverse GRT operator to the scattered wave-field data. Typical GRT-style true-amplitude inversion procedure contains an amplitude compensation process after the weighted migration via dividing an illumination associated matrix whose elements are integrals of scattering angles. It is intuitional to some extent that performs the generalized linear inversion and the inversion of GRT together by this process for direct inversion. However, it is imprecise to carry out such operation when the illumination at the image point is limited, which easily leads to the inaccuracy and instability of the matrix. This paper formulates the GRT true-amplitude inversion framework in an angle-domain version, which naturally degrades the external integral term related to the illumination in the conventional case. We solve the linearized integral equation for combined parameters of different fixed scattering angle values. With this step, we obtain high-quality angle-domain common-image gathers (CIGs) in the migration loop which provide correct amplitude-versus-angle (AVA) behavior and reasonable illumination range for subsurface image points. Then we deal with the over-determined problem to solve each parameter in the combination by a standard optimization operation. The angle-domain GRT inversion method keeps away from calculating the inaccurate and unstable illumination matrix. Compared with the conventional method, the angle-domain method can obtain more accurate amplitude information and wider amplitude-preserved range. Several model tests demonstrate the effectiveness and practicability.

Tribological characterization of TiN coatings prepared by magnetron sputtering

Science.gov (United States)

Makwana, Nishant S.; Chauhan, Kamlesh V.; Sonera, Akshay L.; Chauhan, Dharmesh B.; Dave, Divyeshkumar P.; Rawal, Sushant K.

2018-05-01

Titanium nitride (TiN) coating deposited on aluminium and brass pin substrates using RF reactive magnetron sputtering. The structural properties and surface morphology were characterized by X-ray diffraction (XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). There was formation of (101) Ti2N, (110) TiN2 and (102) TiN0.30 peaks at 3.5Pa, 2Pa and 1.25Pa sputtering pressure respectively. The tribological properties of coating were inspected using pin on disc tribometer equipment. It was observed that TiN coated aluminium and brass pins demonstrated improved wear resistance than uncoated aluminium and brass pins.

Controlled formation of anatase and rutile TiO2 thin films by reactive magnetron sputtering

OpenAIRE

Rafieian Boroujeni, Damon; Ogieglo, Wojciech; Savenije, Tom; Lammertink, Rob G.H.

2015-01-01

We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon annealing to anatase or rutile, depending on the initial sputtering conditions. Substoichiometric films (TiOx

Hollow Core Optical Fiber Gas Lasers: Toward Novel and Practical Systems in Fused Silica

Science.gov (United States)

2017-05-18

Hollow core Optically pumped Fiber Gas LASer’s (HOFGLAS’s) based on population inversion combine advantages of fiber lasers such as long interaction...polarization dependent fiber properties. Preliminary experiments were performed toward simultaneous lasing in the visible and near infrared; lasing in...words) Hollow core Optically pumped Fiber Gas LASer’s (HOFGLAS’s) based on population inversion combine advantages of fiber lasers such as long

Contribution to mechanical and crystallographic analysis of molyledenum layers prepared by magnetron cathode sputtering

International Nuclear Information System (INIS)

Bosland, P.

1988-01-01

Molybdenum coatings presenting different compression stresses are elaborated by magnetron cathode sputtering by varying the negative voltage of the substrate during deposition. Stress evolution is accompanied by crystal texture evolution and argon content incorporated in the layers. Crystallite orientation is explained by a phenomenon similar to canalisation observed in ion implantation. In a same deposit each component presents its own deformations different from neighbouring components [fr

Heliospheric magnetic field polarity inversions driven by radial velocity field structures

Czech Academy of Sciences Publication Activity Database

Landi, S.; Hellinger, Petr; Velli, M.

2006-01-01

Roč. 33, č. 14 (2006), L14101/1-L14101/5 ISSN 0094-8276 Grant - others:European Commission(XE) HRPN-CT-2001-00310 Institutional research plan: CEZ:AV0Z30420517 Keywords : solar wind * magnetic field polarity inversions * microstreams * turbulence Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.602, year: 2006

Determination of the number density of excited and ground Zn atoms during rf magnetron sputtering of ZnO target

Energy Technology Data Exchange (ETDEWEB)

Maaloul, L.; Gangwar, R. K.; Stafford, L., E-mail: luc.stafford@umontreal.ca [Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7 (Canada)

2015-07-15

A combination of optical absorption spectroscopy (OAS) and optical emission spectroscopy measurements was used to monitor the number density of Zn atoms in excited 4s4p ({sup 3}P{sub 2} and {sup 3}P{sub 0}) metastable states as well as in ground 4s{sup 2} ({sup 1}S{sub 0}) state in a 5 mTorr Ar radio-frequency (RF) magnetron sputtering plasma used for the deposition of ZnO-based thin films. OAS measurements revealed an increase by about one order of magnitude of Zn {sup 3}P{sub 2} and {sup 3}P{sub 0} metastable atoms by varying the self-bias voltage on the ZnO target from −115 to −300 V. Over the whole range of experimental conditions investigated, the triplet-to-singlet metastable density ratio was 5 ± 1, which matches the statistical weight ratio of these states in Boltzmann equilibrium. Construction of a Boltzmann plot using all Zn I emission lines in the 200–500 nm revealed a constant excitation temperature of 0.33 ± 0.04 eV. In combination with measured populations of Zn {sup 3}P{sub 2} and {sup 3}P{sub 0} metastable atoms, this temperature was used to extrapolate the absolute number density of ground state Zn atoms. The results were found to be in excellent agreement with those obtained previously by actinometry on Zn atoms using Ar as the actinometer gas [L. Maaloul and L. Stafford, J. Vac. Sci. Technol., A 31, 061306 (2013)]. This set of data was then correlated to spectroscopic ellipsometry measurements of the deposition rate of Zn atoms on a Si substrate positioned at 12 cm away from the ZnO target. The deposition rate scaled linearly with the number density of Zn atoms. In sharp contrast with previous studies on RF magnetron sputtering of Cu targets, these findings indicate that metastable atoms play a negligible role on the plasma deposition dynamics of Zn-based coatings.

THE EFFECT OF PRESSURE, BIAS VOLTAGE AND ANNEALING TEMPERATURE ON N₂ AND N₂+SiH₄ DOPED WC/C DC MAGNETRON SPUTTERED LAYERS

Directory of Open Access Journals (Sweden)

Peter Hornak

2017-12-01

Full Text Available Tungsten carbide (WC/C layers are often researched due to their outstanding mechanical and tribological properties. Here, optimized indented hardness (HIT, indentation modulus (EIT and coefficient of friction (COF values were measured to study the effect of pressure and bias voltage on WC/C layers, deposited on Si by DC magnetron spluttering. Maximal values of HIT=37.2±4.8 GPa, EIT=447±28 GPa and COF=0.64±0.09 were obtained. Additionally, the effect of temperature on optimized layers deposited with and without N₂ and N₂+SiH₄ annealed at 200 °C, 500 °C and 800 °C, were also investigated. The values of HIT, EIT and COF and, observed morphology and structural composition of these contaminated and non-contaminated WC/C layers were evaluated. It was found that layer degradation occurred at different rates depending on the temperature and gas mixture used during the annealing and deposition process, respectively.

Transmission photocathodes based on stainless steel mesh and quartz glass coated with N-doped DLC thin films prepared by reactive magnetron sputtering

Science.gov (United States)

Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Arbet, J.

2016-03-01

The influence was investigated of N-doped diamond-like carbon (DLC) films properties on the quantum efficiency of a prepared transmission photocathode. N-doped DLC thin films were deposited on a silicon substrate, a stainless steel mesh and quartz glass (coated with 5 nm thick Cr adhesion film) by reactive magnetron sputtering using a carbon target and gas mixture Ar, 90%N2+10%H2. The elements' concentration in the films was determined by RBS and ERD. The quantum efficiency was calculated from the measured laser energy and the measured cathode charge. For the study of the vectorial photoelectric effect, the quartz type photocathode was irradiated by intensive laser pulses to form pin-holes in the DLC film. The quantum efficiency (QE), calculated at a laser energy of 0.4 mJ, rose as the nitrogen concentration in the DLC films was increased and rose dramatically after the micron-size perforation in the quartz type photocathodes.

Gas dynamic lasers

International Nuclear Information System (INIS)

Hill, R.J.; Jewell, N.T.

1975-01-01

In a high powered laser system it is proposed that combustion gases be bled off from a gas turbine engine and their composition adjusted by burning extra fuel in the bleed gases or adding extra substances. Suitable aerodynamic expansion produces a population inversion resulting in laser action in the CO 2 species. Alternatively, bleed gases may be taken from the high pressure compressor of the gas turbine engine and an appropriate fuel burned therein. If required, other adjustments may also be made to the composition and the resulting gaseous mixture subjected to aerodynamic expansion to induce laser action as before. (auth)

Development of low temperature RF magnetron sputtered ITO films on flexible substrate

Energy Technology Data Exchange (ETDEWEB)

Muneshwar, T.P.; Varma, V.; Meshram, N; Soni, S.; Dusane, R.O. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

2010-09-15

Indium tin oxide (ITO) is one of the important materials used as transparent conducting oxide (TCO) layer in thin film solar cells, digital displays and other similar applications. For applications involving flexible polymeric substrates, it is important that deposition of ITO is carried out at near room temperature. This requirement puts constraint on stoichiometry leading to undesired electrical and optical properties. Effect of oxygen partial pressure on ITO films deposited on flexible Kapton {sup registered} by the RF magnetron sputtering is reported in this paper. (author)

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 �

Inverse modeling for the determination of hydrogeological parameters of a two-phase system

International Nuclear Information System (INIS)

Finsterle, S.

1993-01-01

Investigations related to the disposal of radioactive wastes in Switzerland are dealing with formations containing natural gas as potential host rock for a repository. Moreover, gas generation in the repository itself may lead to an unsaturated zone of significant extent and impact on the system's performance. The site characterization procedure requires the estimation of hydraulic properties being used as input parameters for a two-phase two-component numerical simulator. In this study, estimates of gas related formation parameters are obtained by inverse modeling. Based on discrete observations of the system's state, model parameters can be estimated within the framework of a given conceptual model by means of optimization techniques. This study presents the theoretical background that relates field data to the model parameters. A parameter estimation procedure is proposed and implemented in a computer code for automatic model calibration. This tool allows to identify key parameters affecting flow of water and gas in porous media. The inverse modeling approach is verified using data from a synthetic laboratory experiment. In addition, the Gastest performed at the Grimsel Test Site is analyzed in order to demonstrate the applicability of the proposed procedure when used with data from a real geologic environment. Estimation of hydrogeologic parameters by automatic model calibration improves the understanding of the two-phase flow processes and therefore increases the reliability of the subsequent simulation runs. (author) figs., tabs., 100 refs

Introduction to gas lasers with emphasis on selective excitation processes

CERN Document Server

Willett, Colin S

1974-01-01

Introduction to Gas Lasers: Population Inversion Mechanisms focuses on important processes in gas discharge lasers and basic atomic collision processes that operate in a gas laser. Organized into six chapters, this book first discusses the historical development and basic principles of gas lasers. Subsequent chapters describe the selective excitation processes in gas discharges and the specific neutral, ionized and molecular laser systems. This book will be a valuable reference on the behavior of gas-discharge lasers to anyone already in the field.

Epitaxial growth of "infinite layer” thin films and multilayers by rf magnetron sputtering

OpenAIRE

Fàbrega, L.; Koller, E.; Triscone, J. M.; Fischer, Ø.

2017-01-01

We report on the preparation and characterization of epitaxial ACuO2 (A = Sr, Ca, Ba) thin films and multilayers with the so- called infinite layer (IL) structure, by rf magnetron sputtering. Films and multilayers without Ba have a remarkable crystal quality, whereas those containing this large ion are often multiphased and unstable. In spite of the excellent crystalline quality of these samples, obtaining thin films having both IL structure and displaying superconducting properties has not s...

Electrochemical characterization of silicon/graphene/MWCNT hybrid lithium-ion battery anodes produced via RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Toçoğlu, Ubeyd, E-mail: utocoglu@sakarya.edu.tr; Hatipoğlu, Gizem; Alaf, Miraç; Kayış, Fuat; Akbulut, Hatem

2016-12-15

Graphical abstract: Silicon/graphene/MWCNT hybrid composite anodes were produced via RF magnetron sputtering technique. CR2016 type coin cells were assembled for electrochemical characterization of anodes. Electrochemical characterizations of anodes were conducted via galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy techniques. - Highlights: • Silicon/graphene/MWCNT hybrid negative lithium ion battery anodes were produced via magnetron sputtering. • Structural and electrochemical characterizations of composite anodes were conducted comprehensively. • The capacity values exhibited by composite anodes were found to be almost more than two times compared to thin film anodes after 100 cycles. - Abstract: In this study it was aimed to enhance cycling performance of silicon lithium ion battery anodes via producing flexible Silicon/Graphene/MWCNT composite structures. The volumetric expansions, which are the primary obstacle that hinders the practical usage of silicon anodes, were tried to suppress using flexible graphene/MWCNT paper substrates. Moreover to achieve lightweight and high electrical conductive anodes, the advantage of graphene was aimed to be exploited. Silicon/graphene/MWCNT flexible composite anodes were produced via radio frequency (RF) magnetron sputtering technique. Graphene/MWCNT papers were produced with vacuum filtration technique as substrate for sputtering process. At coating process of papers constant sputtering power was applied. Phase analysis was conducted with X-ray diffraction (XRD) technique and Raman spectroscopy. Field emission scanning electron microscopy (FESEM). Cyclic voltammetry (CV) tests were carried out to reveal reversible reactions between silicon and lithium. Galvanostatic charge/discharge technique was employed to determine the cyclic performance of anodes. Electrochemical impedance spectroscopy technique was used to understand the relation between cyclic performance and

Electrochemical characterization of silicon/graphene/MWCNT hybrid lithium-ion battery anodes produced via RF magnetron sputtering

International Nuclear Information System (INIS)

Toçoğlu, Ubeyd; Hatipoğlu, Gizem; Alaf, Miraç; Kayış, Fuat; Akbulut, Hatem

2016-01-01

Graphical abstract: Silicon/graphene/MWCNT hybrid composite anodes were produced via RF magnetron sputtering technique. CR2016 type coin cells were assembled for electrochemical characterization of anodes. Electrochemical characterizations of anodes were conducted via galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy techniques. - Highlights: • Silicon/graphene/MWCNT hybrid negative lithium ion battery anodes were produced via magnetron sputtering. • Structural and electrochemical characterizations of composite anodes were conducted comprehensively. • The capacity values exhibited by composite anodes were found to be almost more than two times compared to thin film anodes after 100 cycles. - Abstract: In this study it was aimed to enhance cycling performance of silicon lithium ion battery anodes via producing flexible Silicon/Graphene/MWCNT composite structures. The volumetric expansions, which are the primary obstacle that hinders the practical usage of silicon anodes, were tried to suppress using flexible graphene/MWCNT paper substrates. Moreover to achieve lightweight and high electrical conductive anodes, the advantage of graphene was aimed to be exploited. Silicon/graphene/MWCNT flexible composite anodes were produced via radio frequency (RF) magnetron sputtering technique. Graphene/MWCNT papers were produced with vacuum filtration technique as substrate for sputtering process. At coating process of papers constant sputtering power was applied. Phase analysis was conducted with X-ray diffraction (XRD) technique and Raman spectroscopy. Field emission scanning electron microscopy (FESEM). Cyclic voltammetry (CV) tests were carried out to reveal reversible reactions between silicon and lithium. Galvanostatic charge/discharge technique was employed to determine the cyclic performance of anodes. Electrochemical impedance spectroscopy technique was used to understand the relation between cyclic performance and

Surface composition of magnetron sputtered Pt-Co thin film catalyst for proton exchange membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Vorokhta, Mykhailo, E-mail: vorohtam@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Khalakhan, Ivan; Václavů, Michal [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Kovács, Gábor; Kozlov, Sergey M. [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1, 08028 Barcelona (Spain); Kúš, Peter; Skála, Tomáš; Tsud, Natalia; Lavková, Jaroslava [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Potin, Valerie [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université Bourgogne, 9 Av. A. Savary, BP 47870, F-21078 Dijon Cedex (France); and others

2016-03-01

Graphical abstract: - Highlights: • Nanostructured Pt-Co thin catalyst films were grown on carbon by magnetron sputtering. • The surface composition of the nanostructured Pt-Co films was investigated by surface analysis techniques. • We carried out modeling of Pt-Co nanoalloys by computational methods. • Both experiment and modeling based on density functional theory showed that the surface of Pt-Co nanoparticles is almost exclusively composed of Pt atoms. - Abstract: Recently we have tested a magnetron sputtered Pt-Co catalyst in a hydrogen-fed proton exchange membrane fuel cell and showed its high catalytic activity for the oxygen reduction reaction. Here we present further investigation of the magnetron sputtered Pt-Co thin film catalyst by both experimental and theoretical methods. Scanning electron microscopy and transmission electron microscopy experiments confirmed the nanostructured character of the catalyst. The surface composition of as-deposited and annealed at 773 K Pt-Co films was investigated by surface analysis techniques, such as synchrotron radiation photoelectron spectroscopy and X-ray photoelectron spectroscopy. Modeling based on density functional theory showed that the surface of 6 nm large 1:1 Pt-Co nanoparticles is almost exclusively composed of Pt atoms (>90%) at typical operation conditions and the Co content does not exceed 20% at 773 K, in agreement with the experimental characterization of such films annealed in vacuum. According to experiment, the density of valence states of surface atoms in Pt-Co nanostructures is shifted by 0.3 eV to higher energies, which can be associated with their higher activity in the oxygen reduction reaction. The changes in electronic structure caused by alloying are also reflected in the measured Pt 4f, Co 3p and Co 2p photoelectron peak binding energies.

Arab oil and gas

International Nuclear Information System (INIS)

Anon.

1993-01-01

This review explains the situation of petroleum products and gas in Arab countries. Several kinds of difficulties are exposed: too many projects, concurrence of other producers like Australia, Indonesia, Malaysia, Norway, Russian Federation, will be rude. New exporters (Iran, Venezuela, Nigeria, even Alaska) will appear and will want a part of market and western countries will probably diversify their tradesmen. An other point is that producers overestimate future growth of worldwide demand or underestimate the impact of more expansive gas price on this demand. Inversely if this one is too low, several projects, would not be profitable. The last point is in the concurrence between gas and petroleum products, which needs a consistent policy

Investigation of Rising-Sun Magnetrons Operated at Relativistic Voltages Using Three Dimensional Particle-in-Cell Simulation

International Nuclear Information System (INIS)

Lemke, R.W.; Genoni, T.C.; Spencer, T.A.

1999-01-01

This work is an attempt to elucidate effects that may limit efficiency in magnetrons operated at relativistic voltages (V ∼ 500 kV). Three-dimensional particle-in-cell simulation is used to investigate the behavior of 14 and 22 cavity, cylindrical, rising-sun magnetrons. Power is extracted radially through a single iris located at the end of every other cavity. Numerical results show that in general output power and efficiency increase approximately linearly with increasing iris width (decreasing vacuum Q) until the total Q becomes too low for stable oscillation in the n-mode to be maintained. Beyond this point mode competition and/or switching occur and efficiency decreases. Results reveal that the minimum value of Q (maximum efficiency) that can be achieved prior to the onset of mode competition is significantly affected by the magnitude of the 0-space-harmonic of the π-mode, a unique characteristic of rising-suns, and by the magnitude of the electron current density (space-charge effects). By minimizing these effects, up to 3.7 GW output power has been produced at an efficiency of 40%

Effect of interelectrode distance on dc magnetron current-pressure characteristics

Science.gov (United States)

Mankelevich, Yu A.; Pal, A. F.; Ryabinkin, A. N.; Serov, A. O.

2018-01-01

The current-pressure (I-P) non-monotonic characteristic in the magnetron discharge dc in argon at different interelectrode distances was investigated. The ion spatial distribution was obtained with optical emission spectroscopy and the characteristic dimensions of the discharge structure in near cathode region were determined. It is shown that decreasing the distance between electrodes does not affect the shape and position of the nonmonotonic part of I-P characteristic until this distance become comparable with the dimensions of the ionization region near cathode. The existence of non-monotonic part of I-P characteristic is determined by the processes in the near cathode region and is probably unrelated with the cold electron transfer in the rest of the plasma.

Inversions

Science.gov (United States)

Brown, Malcolm

2009-01-01

Inversions are fascinating phenomena. They are reversals of the normal or expected order. They occur across a wide variety of contexts. What do inversions have to do with learning spaces? The author suggests that they are a useful metaphor for the process that is unfolding in higher education with respect to education. On the basis of…

Urea impedimetric biosensor based on reactive RF magnetron sputtered zinc oxide nanoporous transducer

International Nuclear Information System (INIS)

Mozaffari, Sayed Ahmad; Rahmanian, Reza; Abedi, Mohammad; Amoli, Hossein Salar

2014-01-01

Graphical abstract: - Highlights: • Application and optimization of reactive RF magnetron sputtering for homogeneous nanoporous ZnO thin film formation. • Exploiting nanoporous ZnO thin film as a good porous framework with large surface area/volume for having stable immobilized enzyme with minimum loss of activity. • Application of impedimetric assessment for urea biosensing due to its rapidity, sensitivity, and repeatability. - Abstract: Uniform sputtered nanoporous zinc oxide (Nano-ZnO) thin film on the conductive fluorinated-tin oxide (FTO) layer was applied to immobilize urease enzyme (Urs) for urea detection. Highly uniform nanoporous ZnO thin film were obtained by reactive radio frequency (RF) magnetron sputtering system at the optimized instrumental deposition conditions. Characterization of the surface morphology and roughness of ZnO thin film by field emission-scanning electron microscopy (FE-SEM) exhibits cavities of nanoporous film as an effective biosensing area for enzyme immobilization. Step by step monitoring of FTO/Nano-ZnO/Urs biosensor fabrication were performed using electrochemical methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Fabricated FTO/Nano-ZnO/Urs biosensor was used for urea determination using EIS experiments. The impedimetric results show high sensitivity for urea detection within 0.83–23.24 mM and limit of detection as 0.40 mM

Structure and morphology of magnetron sputter deposited ultrathin ZnO films on confined polymeric template

Science.gov (United States)

Singh, Ajaib; Schipmann, Susanne; Mathur, Aakash; Pal, Dipayan; Sengupta, Amartya; Klemradt, Uwe; Chattopadhyay, Sudeshna

2017-08-01

The structure and morphology of ultra-thin zinc oxide (ZnO) films with different film thicknesses on confined polymer template were studied through X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS). Using magnetron sputter deposition technique ZnO thin films with different film thicknesses (weight of polystyrene). The detailed internal structure, along the surface/interfaces and the growth direction of the system were explored in this study, which provides insight into the growth procedure of ZnO on confined polymer and reveals that a thin layer of ZnO, with very low surface and interface roughness, can be grown by DC magnetron sputtering technique, with approximately full coverage (with bulk like electron density) even in nm order of thickness, in 2-7 nm range on confined polymer template, without disturbing the structure of the underneath template. The resulting ZnO-polystyrene hybrid systems show strong ZnO near band edge (NBE) and deep-level (DLE) emissions in their room temperature photoluminescence spectra, where the contribution of DLE gets relatively stronger with decreasing ZnO film thickness, indicating a significant enhancement of surface defects because of the greater surface to volume ratio in thinner films.

Incorporation of N in TiO{sub 2} films grown by DC-reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Serio, S. [CEFITEC, Departamento de Fisica, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Melo Jorge, M.E. [CCMM, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande C8, 1749-016 Lisboa (Portugal); Nunes, Y. [CEFITEC, Departamento de Fisica, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Barradas, N.P. [Instituto Tecnologico e Nuclear and CFNUL, E.N. 10, Sacavem 2686-953 (Portugal); Alves, E., E-mail: ealves@itn.pt [Instituto Tecnologico e Nuclear and CFNUL, E.N. 10, Sacavem 2686-953 (Portugal); Munnik, F. [Helmholtz-Zentrum Dresden-Rossendorf (Germany)

2012-02-15

Photocatalytic properties of TiO{sub 2} are expected to play an important role on emerging technologies based on OH radicals to destroy harmful nonbiodegradable organic and inorganic contaminants in water. The drawback is the wide band gap of TiO{sub 2} (3.2 eV) limiting its use to the UV part of electromagnetic spectrum under sunlight. Therefore, modifications of TiO{sub 2} are needed to tune the gap in order to allow an efficient use of the entire solar spectrum. One possibility is N-doping of TiO{sub 2} to make the photocatalytic activity possible under visible light and more suitable for water treatment. In our study nitrogen-doped TiO{sub 2} (TiO{sub 2-x}N{sub x}) films were deposited by DC-reactive magnetron sputtering using a dual-magnetron co-deposition apparatus on unheated glass and silicon substrates using a pure titanium target. The depth profile of nitrogen was measured with heavy ion elastic recoil detection analysis combined with Rutherford backscattering spectrometry (RBS) and correlated with the optical and structural properties obtained by UV-VIS spectroscopy and X-ray diffraction (XRD).

Investigation of DC magnetron-sputtered TiO2 coatings: Effect of coating thickness, structure, and morphology on photocatalytic activity

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Shabadi, Rajashekhara; Galca, Aurelian Catalin

2014-01-01

The photocatalytic performance of magnetron-sputtered titanium dioxide (TiO2) coatings of different thickness in anatase crystalline structure deposited on aluminium 1050 alloy substrates was investigated using a combination of photo-electrochemistry, methylene blue decomposition, and microscopic...

Domino Platform: PVD Coaters for Arc Evaporation and High Current Pulsed Magnetron Sputtering

International Nuclear Information System (INIS)

Vetter, J; Müller, J; Erkens, G

2012-01-01

AlTiN and CrN coatings were deposited in hybrid DOMINO platforms by magnetron sputtering (DC-MS, DC-MS+HCP-MS, HCP-MS) and vacuum arc evaporation. The ion cleaning was done by the AEGD process. The coating rates and the energy efficiency of both deposition processes were compared. The roughness effects of the different coating types were discussed. Preliminary results of the change of pulse characteristics during simultaneously running of HCP-MS plus vacuum arc evaporation are shown.

Contamination of magnetron sputtered metallic films by oxygen from residual atmosphere in deposition chamber

Czech Academy of Sciences Publication Activity Database

Pokorný, Petr; Musil, Jindřich; Fitl, Přemysl; Novotný, Michal; Lančok, Ján; Bulíř, Jiří

2015-01-01

Roč. 12, č. 5 (2015), s. 416-421 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR(CZ) GAP108/11/1312; GA ČR(CZ) GAP108/11/0958; GA ČR(CZ) GA14-10279S Institutional support: RVO:68378271 Keywords : contamination * low-pressure discharges * magnetron * metallic films * sputtering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.713, year: 2015

Inverse Cerenkov experiment

International Nuclear Information System (INIS)

Kimura, W.D.

1993-01-01

The final report describes work performed to investigate inverse Cherenkov acceleration (ICA) as a promising method for laser particle acceleration. In particular, an improved configuration of ICA is being tested in a experiment presently underway on the Accelerator Test Facility (ATF). In the experiment, the high peak power (∼ 10 GW) linearly polarized ATF CO 2 laser beam is converted to a radially polarized beam. This is beam is focused with an axicon at the Cherenkov angle onto the ATF 50-MeV e-beam inside a hydrogen gas cell, where the gas acts as the phase matching medium of the interaction. An energy gain of ∼12 MeV is predicted assuming a delivered laser peak power of 5 GW. The experiment is divided into two phases. The Phase I experiments, which were completed in the spring of 1992, were conducted before the ATF e-beam was available and involved several successful tests of the optical systems. Phase II experiments are with the e-beam and laser beam, and are still in progress. The ATF demonstrated delivery of the e-beam to the experiment in Dec. 1992. A preliminary ''debugging'' run with the e-beam and laser beam occurred in May 1993. This revealed the need for some experimental modifications, which have been implemented. The second run is tentatively scheduled for October or November 1993. In parallel to the experimental efforts has been ongoing theoretical work to support the experiment and investigate improvement and/or offshoots. One exciting offshoot has been theoretical work showing that free-space laser acceleration of electrons is possible using a radially-polarized, axicon-focused laser beam, but without any phase-matching gas. The Monte Carlo code used to model the ICA process has been upgraded and expanded to handle different types of laser beam input profiles

Composite TiO2/hydrocarbon plasma polymer films prepared by magnetron sputtering of TiO2 and poly(propylene)

Czech Academy of Sciences Publication Activity Database

Drabik, M.; Hanuš, J.; Kousal, J.; Choukourov, A.; Biederman, H.; Slavínská, D.; Macková, Anna; Pešička, J.

2007-01-01

Roč. 4, č. 6 (2007), s. 654-663 ISSN 1612-8850 Institutional research plan: CEZ:AV0Z10480505 Keywords : composite thin films * magnetron * poly(propylene) (PP) Subject RIV: BE - Theoretical Physics Impact factor: 2.132, year: 2007

Structure and morphology of magnetron sputter deposited ultrathin ZnO films on confined polymeric template

Energy Technology Data Exchange (ETDEWEB)

Singh, Ajaib [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Schipmann, Susanne [II. Insatitute of Physics and JARA-FIT, RWTH Aachen University, 52056 Aachen (Germany); Mathur, Aakash; Pal, Dipayan [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Sengupta, Amartya [Department of Physics, Indian Institute of Technology Delhi, Delhi 110016 (India); Klemradt, Uwe [II. Insatitute of Physics and JARA-FIT, RWTH Aachen University, 52056 Aachen (Germany); Chattopadhyay, Sudeshna, E-mail: sudeshna@iiti.ac.in [Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Indore 453552 (India); Discipline of Physics, Indian Institute of Technology Indore, Indore 453552 (India); Centre for Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore 453552 (India)

2017-08-31

Highlights: • Ultra-thin ZnO films grown on confined polymeric (polystyrene, PS) template. • XRR and GISAXS explore the surface/interfaces structure and morphology of ZnO/PS. • Insights into the growth mechanism of magnetron sputtered ZnO thin film on PS template. • Nucleated disk-like cylindrical particles are the basis of the formation of ZnO layers. • Effect of ZnO film thickness on room temperature PL spectra in ZnO/PS systems. - Abstract: The structure and morphology of ultra-thin zinc oxide (ZnO) films with different film thicknesses on confined polymer template were studied through X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS). Using magnetron sputter deposition technique ZnO thin films with different film thicknesses (<10 nm) were grown on confined polystyrene with ∼2R{sub g} film thickness, where R{sub g} ∼ 20 nm (R{sub g} is the unperturbed radius of gyration of polystyrene, defined by R{sub g} = 0.272 √M{sub 0}, and M{sub 0} is the molecular weight of polystyrene). The detailed internal structure, along the surface/interfaces and the growth direction of the system were explored in this study, which provides insight into the growth procedure of ZnO on confined polymer and reveals that a thin layer of ZnO, with very low surface and interface roughness, can be grown by DC magnetron sputtering technique, with approximately full coverage (with bulk like electron density) even in nm order of thickness, in 2–7 nm range on confined polymer template, without disturbing the structure of the underneath template. The resulting ZnO-polystyrene hybrid systems show strong ZnO near band edge (NBE) and deep-level (DLE) emissions in their room temperature photoluminescence spectra, where the contribution of DLE gets relatively stronger with decreasing ZnO film thickness, indicating a significant enhancement of surface defects because of the greater surface to volume ratio in thinner films.

Synthesis of Nanoparticle Model Systems for Sustainable Catalysis by Gas Aggregation

DEFF Research Database (Denmark)

Bodin, Anders

The overall goal of this thesis is to develop better catalysts for chemical reactions used in sustainable energy storage and environmental protection. Specifically, the thesis presents research on well-defined catalyst model systems of nanoparticles synthesized by magnetron sputtering, gas......−Mo−S Nanoparticles by Reactive Gas Aggregation: In this project, a method was developed for synthesizing in-flight sulfided Ni-Mo-S nanoparticles by aggregation of sputtered metal from a Mo75Ni25 target in a reactive atmosphere of Ar and H2S. The resulting particles are undersulfided with a stoichiometry of Mo0.8Ni0...... keys to developing better catalysts for energy-storage by electrolysis of CO2 is to understand the principles behind electroreduction of the reaction intermediate CO. This study reports the discovery of a high, transient production of methane at the onset of electroreduction of CO on mass-selected copper...

Inverse modeling of test SB4-VM2/216.7 at Wellenberg

International Nuclear Information System (INIS)

Finsterle, S.

1994-03-01

Pressure and flow rate data from a water sampling test, which also produced gas, at the Wellenberg site are analyzed using inverse modeling techniques. Two conceptual models are developed and used for parameter estimation. The first model assumes that the gas observed at the surface is dissolved in the pore water under natural pressure and temperature conditions and comes out of solution due to the pressure reduction during pumping. The second model considers a mobile gas phase originally present in the formation. While both models are able to explain the observed pressure response as well as the gas seen at the surface, large uncertainties in the data and in the model assumptions inhibit the determination of two-phase flow parameters. The analysis indicates, however, that the formation has a very low permeability and that formation head is far below hydrostatic

Nitrogen Atom Energy Distributions in a Hollow-cathode Planar Sputtering Magnetron

International Nuclear Information System (INIS)

Ruzic, D.N.; Goeckner, M.J.; Cohen, S.A.; Wang, Zhehui

1999-01-01

Energy distributions of N atoms in a hollow-cathode planar sputtering magnetron were obtained by use of optical emission spectroscopy. A characteristic line, N I 8216.3 , well-separated from molecular nitrogen emission bands, was identified. Jansson's nonlinear spectral deconvolution method, refined by minimization of χ w ampersand sup2; , was used to obtain the optimal deconvolved spectra. These showed nitrogen atom energies from 1 eV to beyond 500 eV. Based on comparisons with VFTRIM results, we propose that the energetic N atoms are generated from N 2 + ions after these ions are accelerated through the sheath and dissociatively reflect from the cathode

Venting temperature determines surface chemistry of magnetron sputtered TiN films

Energy Technology Data Exchange (ETDEWEB)

Greczynski, G. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden); Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Mráz, S.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden)

2016-01-25

Surface properties of refractory ceramic transition metal nitride thin films grown by magnetron sputtering are essential for resistance towards oxidation necessary in all modern applications. Here, typically neglected factors, including exposure to residual process gases following the growth and the venting temperature T{sub v}, each affecting the surface chemistry, are addressed. It is demonstrated for the TiN model materials system that T{sub v} has a substantial effect on the composition and thickness-evolution of the reacted surface layer and should therefore be reported. The phenomena are also shown to have impact on the reliable surface characterization by x-ray photoelectron spectroscopy.

Amorphous indium-tin-zinc oxide films deposited by magnetron sputtering with various reactive gases: Spatial distribution of thin film transistor performance

International Nuclear Information System (INIS)

Jia, Junjun; Torigoshi, Yoshifumi; Shigesato, Yuzo; Kawashima, Emi; Utsuno, Futoshi; Yano, Koki

2015-01-01

This work presents the spatial distribution of electrical characteristics of amorphous indium-tin-zinc oxide film (a-ITZO), and how they depend on the magnetron sputtering conditions using O 2 , H 2 O, and N 2 O as the reactive gases. Experimental results show that the electrical properties of the N 2 O incorporated a-ITZO film has a weak dependence on the deposition location, which cannot be explained by the bombardment effect of high energy particles, and may be attributed to the difference in the spatial distribution of both the amount and the activity of the reactive gas reaching the substrate surface. The measurement for the performance of a-ITZO thin film transistor (TFT) also suggests that the electrical performance and device uniformity of a-ITZO TFTs can be improved significantly by the N 2 O introduction into the deposition process, where the field mobility reach to 30.8 cm 2 V –1 s –1 , which is approximately two times higher than that of the amorphous indium-gallium-zinc oxide TFT

A study of the transient plasma potential in a pulsed bi-polar dc magnetron discharge

International Nuclear Information System (INIS)

Bradley, J W; Karkari, S K; Vetushka, A

2004-01-01

The temporal evolution of the plasma potential, V p , in a pulsed dc magnetron plasma has been determined using the emissive probe technique. The discharge was operated in the 'asymmetric bi-polar' mode, in which the discharge voltage changes polarity during part of the pulse cycle. The probe measurements, with a time-resolution of 20 ns or better, were made along a line above the racetrack, normal to the plane of the cathode target, for a fixed frequency (100 kHz), duty cycle (50%), argon pressure (0.74 Pa) and discharge power (583 W). At all the measured positions, V p was found to respond to the large and rapid changes in the cathode voltage, V d , during the different phases of the pulse cycle, with V p always more positive than V d . At a typical substrate position (>80 mm from the target), V p remains a few volts above the most positive surface in the discharge at all times. In the 'on' phase of the pulse, the measurements show a significant axial electric field is generated in the plasma, with the plasma potential dropping by a total of about 30 V over a distance of 70 mm, from the bulk plasma to a position close to the beginning of the cathode fall. This is consistent with measurements made in the dc magnetron. During the stable 'reverse' phase of the discharge, for distances greater than 18 mm from the target, the axial electric field is found to collapse, with V p elevated uniformly to about 3 V above V d . Between the target and this field-free region an ion sheath forms, and the current flowing to the target is still an ion current in this 'reverse' period. During the initial 200 ns of the voltage 'overshoot' phase (between 'on' and 'reverse' phases), V d reached a potential of +290 V; however, close to the target, V p was found to attain a much higher value, namely +378 V. Along the line of measurement, the axial electric field reverses in direction in this phase, and an electron current of up to 9 A flows to the target. The spatial and temporal

Thermal stability of electrical properties of ZnO:Al films deposited by room temperature magnetron sputtering

International Nuclear Information System (INIS)

Wang Tao; Diao Xungang; Ding Peng

2011-01-01

Research highlights: → Real-time sheet resistance (R s ) of ZnO:Al films heated in Ar gas was measured by a dada capturer. → Results revealed that R s of the film heated at 100 o C was reduced throughout the annealing. → R s of the films annealed over 100 o C was reduced at early stage but then increased all along to the end. → Some novel R s change points that need more penetrations were detected by the self designed capturer. - Abstract: In order to investigate the thermal stability of electrical properties for aluminum doped zinc oxide (ZnO:Al, AZO) films deposited by direct current reactive magnetron sputtering, AZO films deposited from an alloy target (0.8 wt.% Al) on soda-lime glasses were annealed in argon gas at different temperatures. A data capturer was applied to monitor and collect real-time sheet resistance (R s ) of the films throughout the annealing. Results revealed that R s of the film heated at 100 o C was reduced throughout the annealing, however, conductivity of the films annealed over 100 o C was improved at early stage but then deteriorated all along to the end. Some novel R s change points which need more penetrations were detected. The experimental results obtained from electron diffraction spectrum, X-ray diffraction pattern, X-ray photoelectron spectrum, and Hall measurement were analyzed to explore the effect of the annealing on the electrical properties of AZO films. It was found that the exotic element, which might influence the film properties, was not observed. It was also suggested that the transformation of the crystalline structure and surface chemical bonding states, which resulted in the decrease of carrier concentration and mobility could be the reason for the conductivity degeneration of the films annealed at higher temperature.

Electrical and optical properties of reactive dc magnetron sputtered silver-doped indium oxide thin films: role of oxygen

International Nuclear Information System (INIS)

Subrahmanyam, A.; Barik, U.K.

2006-01-01

Silver-doped indium oxide thin films have been prepared on glass and quartz substrates at room temperature (300 K) by a reactive dc magnetron sputtering technique using an alloy target of pure indium and silver (80:20 at. %). During sputtering, the oxygen flow rates are varied in the range 0.00-2.86 sccm keeping the magnetron power constant at 40 W. The resistivity of these films is in the range 10 0 -10 -3 Ωcm and they show a negative temperature coefficient of resistivity. The films exhibit p-type conductivity at an oxygen flow rate of 1.71 sccm. The work function of these silver-indium oxide films has been measured by a Kelvin probe technique. The refractive index of the films (at 632.8 nm) varies in the range 1.13-1.20. Silver doping in indium oxide narrows the band gap of indium oxide (3.75 eV). (orig.)

Electrical and optical properties of reactive dc magnetron sputtered silver-doped indium oxide thin films: role of oxygen

Energy Technology Data Exchange (ETDEWEB)

Subrahmanyam, A; Barik, U K [Indian Institute of Technology Madras, Semiconductor Physics Laboratory, Department of Physics, Chennai (India)

2006-07-15

Silver-doped indium oxide thin films have been prepared on glass and quartz substrates at room temperature (300 K) by a reactive dc magnetron sputtering technique using an alloy target of pure indium and silver (80:20 at. %). During sputtering, the oxygen flow rates are varied in the range 0.00-2.86 sccm keeping the magnetron power constant at 40 W. The resistivity of these films is in the range 10{sup 0}-10{sup -3} {omega}cm and they show a negative temperature coefficient of resistivity. The films exhibit p-type conductivity at an oxygen flow rate of 1.71 sccm. The work function of these silver-indium oxide films has been measured by a Kelvin probe technique. The refractive index of the films (at 632.8 nm) varies in the range 1.13-1.20. Silver doping in indium oxide narrows the band gap of indium oxide (3.75 eV). (orig.)

High density flux of Co nanoparticles produced by a simple gas aggregation apparatus

Energy Technology Data Exchange (ETDEWEB)

Landi, G. T.; Romero, S. A.; Santos, A. D. [Departamento de Fisica dos Materiais e Mecanica, Laboratorio de Materiais Magneticos, Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil)

2010-03-15

Gas aggregation is a well known method used to produce clusters of different materials with good size control, reduced dispersion, and precise stoichiometry. The cost of these systems is relatively high and they are generally dedicated apparatuses. Furthermore, the usual sample production speed of these systems is not as fast as physical vapor deposition devices posing a problem when thick samples are needed. In this paper we describe the development of a multipurpose gas aggregation system constructed as an adaptation to a magnetron sputtering system. The cost of this adaptation is negligible and its installation and operation are both remarkably simple. The gas flow for flux in the range of 60-130 SCCM (SCCM denotes cubic centimeter per minute at STP) is able to completely collimate all the sputtered material, producing spherical nanoparticles. Co nanoparticles were produced and characterized using electron microscopy techniques and Rutherford back-scattering analysis. The size of the particles is around 10 nm with around 75 nm/min of deposition rate at the center of a Gaussian profile nanoparticle beam.

Nanocomposite metal/plasma polymer films prepared by means of gas aggregation cluster source

Energy Technology Data Exchange (ETDEWEB)

Polonskyi, O.; Solar, P.; Kylian, O.; Drabik, M.; Artemenko, A.; Kousal, J.; Hanus, J.; Pesicka, J.; Matolinova, I. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Kolibalova, E. [Tescan, Libusina trida 21, 632 00 Brno (Czech Republic); Slavinska, D. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Biederman, H., E-mail: bieder@kmf.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic)

2012-04-02

Nanocomposite metal/plasma polymer films have been prepared by simultaneous plasma polymerization using a mixture of Ar/n-hexane and metal cluster beams. A simple compact cluster gas aggregation source is described and characterized with emphasis on the determination of the amount of charged clusters and their size distribution. It is shown that the fraction of neutral, positively and negatively charged nanoclusters leaving the gas aggregation source is largely influenced by used operational conditions. In addition, it is demonstrated that a large portion of Ag clusters is positively charged, especially when higher currents are used for their production. Deposition of nanocomposite Ag/C:H plasma polymer films is described in detail by means of cluster gas aggregation source. Basic characterization of the films is performed using transmission electron microscopy, ultraviolet-visible and Fourier-transform infrared spectroscopies. It is shown that the morphology, structure and optical properties of such prepared nanocomposites differ significantly from the ones fabricated by means of magnetron sputtering of Ag target in Ar/n-hexane mixture.

High density flux of Co nanoparticles produced by a simple gas aggregation apparatus

International Nuclear Information System (INIS)

Landi, G. T.; Romero, S. A.; Santos, A. D.

2010-01-01

Gas aggregation is a well known method used to produce clusters of different materials with good size control, reduced dispersion, and precise stoichiometry. The cost of these systems is relatively high and they are generally dedicated apparatuses. Furthermore, the usual sample production speed of these systems is not as fast as physical vapor deposition devices posing a problem when thick samples are needed. In this paper we describe the development of a multipurpose gas aggregation system constructed as an adaptation to a magnetron sputtering system. The cost of this adaptation is negligible and its installation and operation are both remarkably simple. The gas flow for flux in the range of 60-130 SCCM (SCCM denotes cubic centimeter per minute at STP) is able to completely collimate all the sputtered material, producing spherical nanoparticles. Co nanoparticles were produced and characterized using electron microscopy techniques and Rutherford back-scattering analysis. The size of the particles is around 10 nm with around 75 nm/min of deposition rate at the center of a Gaussian profile nanoparticle beam.

Slow photon amplification of gas-phase ethanol photo-oxidation in titania inverse opal photonic crystals

Energy Technology Data Exchange (ETDEWEB)

Jovic, Vedran, E-mail: vjov001@aucklanduni.ac.nz [School of Chemical Sciences, Science Centre, Building 301, 23 Symonds Street, Auckland 92019 (New Zealand); Idriss, Hicham, E-mail: IdrissH@sabic.com [Corporate Research and Development (CRD), Saudi Basic Industries Corporation (SABIC) at KAUST (Saudi Arabia); Waterhouse, Geoffrey I.N., E-mail: g.waterhouse@auckland.ac.nz [School of Chemical Sciences, Science Centre, Building 301, 23 Symonds Street, Auckland 92019 (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Dodd Walls Centre for Photonic and Quantum Technologies (New Zealand)

2016-11-10

Here we describe the successful fabrication of six titania inverse opal (TiO{sub 2} IO) photocatalysts with fcc[1 1 1] pseudo photonic band gaps (PBGs) tuned to span the UV–vis region. Photocatalysts were fabricated by a colloidal crystal templating and sol-gel approach – a robust and highly applicable bottom-up scheme which allowed for precise control over the geometric and optical properties of the TiO{sub 2} IO photocatalysts. Optical properties of the TiO{sub 2} IO thin films were investigated in detail by UV–vis transmittance and reflectance measurements. The PBG along the fcc[1 1 1] direction in the TiO{sub 2} IOs was dependent on the inter-planar spacing in the [1 1 1] direction, the incident angle of light and the refractive index of the medium filling the macropores in the IOs, in agreement with a modified Bragg’s law expression. Calculated photonic band structures for the photocatalysts revealed a PBG along the Γ → L direction at a/λ ∼ 0.74, in agreement with the experimental optical data. By coupling the low frequency edge of the PBG along the [1 1 1] direction with the electronic absorption edge of anatase TiO{sub 2}, a two-fold enhancement in the rate of gas phase ethanol photo-oxidation in air was achieved. This enhancement appears to be associated with a ‘slow photon’ effect that acts to both enhance TiO{sub 2} absorption and inhibit spontaneous emission (i.e. suppress electron-hole pair recombination).

Direct and inverse neural networks modelling applied to study the influence of the gas diffusion layer properties on PBI-based PEM fuel cells

Energy Technology Data Exchange (ETDEWEB)

Lobato, Justo; Canizares, Pablo; Rodrigo, Manuel A.; Linares, Jose J. [Chemical Engineering Department, University of Castilla-La Mancha, Campus Universitario s/n, 13004 Ciudad Real (Spain); Piuleac, Ciprian-George; Curteanu, Silvia [Faculty of Chemical Engineering and Environmental Protection, Department of Chemical Engineering, ' ' Gh. Asachi' ' Technical University Iasi Bd. D. Mangeron, No. 71A, 700050 IASI (Romania)

2010-08-15

This article shows the application of a very useful mathematical tool, artificial neural networks, to predict the fuel cells results (the value of the tortuosity and the cell voltage, at a given current density, and therefore, the power) on the basis of several properties that define a Gas Diffusion Layer: Teflon content, air permeability, porosity, mean pore size, hydrophobia level. Four neural networks types (multilayer perceptron, generalized feedforward network, modular neural network, and Jordan-Elman neural network) have been applied, with a good fitting between the predicted and the experimental values in the polarization curves. A simple feedforward neural network with one hidden layer proved to be an accurate model with good generalization capability (error about 1% in the validation phase). A procedure based on inverse neural network modelling was able to determine, with small errors, the initial conditions leading to imposed values for characteristics of the fuel cell. In addition, the use of this tool has been proved to be very attractive in order to predict the cell performance, and more interestingly, the influence of the properties of the gas diffusion layer on the cell performance, allowing possible enhancements of this material by changing some of its properties. (author)

Synthesis and characterization of boron carbon nitride films by radio frequency magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.F.; Bello, I.; Lei, M.K.; Lee, C.S.; Lee, S.T. [City Univ. of Hong Kong, Kowloon (Hong Kong). Dept. of Physics and Materials Science; Li, K.Y. [Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong, Kowloon (Hong Kong)

2000-06-01

Boron carbon nitride (BCN) films were deposited on silicon substrates by radio frequency (r.f.) (13.56 MHz) magnetron sputtering from hexagonal boron nitride (h-BN) and graphite targets in an Ar-N{sub 2} gas mixture of a constant pressure of 1.0 Pa. During deposition, the substrates were maintained at a temperature of 400 C and negatively biased using a pulsed voltage with a frequency of 330 kHz. Different analysis techniques such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD) and scanning Auger electron microscopy (SAM) were used for characterization. In addition, the mechanical and tribological properties of the films were investigated by nano-indentation and micro-scratching. The carbon concentration in the films could be adjusted by the coverage area of a graphite sheet on the h-BN target, and decreased with increasing bias voltage. It was found that the ternary compound films within the B-C-N composition triangle possessed a less ordered structure. B--N, B--C and C--N chemical bonds were established in the films, and no phase separation of graphite and h-BN occurred. At zero bias voltage, amorphous BC{sub 2}N films with atomically smooth surface could be obtained, and the microfriction coefficient was 0.11 under a normal load of 1000 {mu}N. Hardness as determined by nano-indentation was usually in the range of 10-30 GPa, whereas the Young's modulus was within 100-200 GPa. (orig.)

Effect of gas ratio on tribological properties of sputter deposited TiN coatings

Energy Technology Data Exchange (ETDEWEB)

Chavda, Mahesh R., E-mail: maheshchavda1990@gmail.com [Department of Mechanical Engineering, Dr. Jivraj Mehta Institute of Technology, Mogar-388340 (India); Chauhan, Kamlesh V.; Rawal, Sushant K., E-mail: sushantrawal.me@charusat.ac.in [CHAMOS Matrusanstha Department of Mechanical Engineering, Chandubhai S. Patel Institute of Technology, Charotar University of Science and Technology (CHARUSAT), Changa-388421 (India)

2016-05-06

Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N{sub 2})gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

Generation of positive and negative oxygen ions in magnetron discharge during reactive sputtering of alumina

Czech Academy of Sciences Publication Activity Database

Pokorný, Petr; Bulíř, Jiří; Lančok, Ján; Musil, Jindřich; Novotný, Michal

2010-01-01

Roč. 7, č. 11 (2010), s. 910-914 ISSN 1612-8850 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : aluminium oxide * ion-energy distribution function * magnetron * mass spectrometry * pulsed discharges Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.643, year: 2010

Magnetron with flux switching cathode and method of operation

Science.gov (United States)

Aaron, D.B.; Wiley, J.D.

1989-09-12

A magnetron sputtering apparatus is formed with a plurality of cells each for generating an independent magnetic field within a different region in the chamber of the apparatus. Each magnetic field aids in maintaining an ion plasma in the respective region of the chamber. One of a plurality of sputtering material targets is positioned on an electrode adjacent to each region so that said ions strike the target ejecting some of the target material. By selectively generating each magnetic field, the ion plasma may be moved from region to region to sputter material from different targets. The sputtered material becomes deposited on a substrate mounted on another electrode within the chamber. The duty cycle of each cell can be dynamically varied during the deposition to produce a layer having a graded composition throughout its thickness. 5 figs.

Structural and optical properties of (Sr,Ba)2SiO4:Eu2+ thin films grown by magnetron sputtering

International Nuclear Information System (INIS)

Li, Leliang; Zheng, Jun; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

2014-01-01

(Sr,Ba) 2 SiO 4 :Eu 2+ thin films were deposited on Si at different substrate temperatures by magnetron sputtering. The morphology and crystalline phases of the films were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements, respectively. The silicate crystal phase was presented when films were annealed above 900 °C and the annealing temperature had great impact on the film morphology. The samples annealed at 1000 °C in a non-reducing atmosphere for 30 s show intense room temperature Eu 2+ emission. These findings may open a promising way to prepare efficient phosphor thin films for on-chip light emitting diodes application. - Highlights: • The (Sr, Ba) 2 SiO 4 :Eu 2+ films are fabricated by magnetron sputtering. • A very strong RT PL emission at 540 nm is achieved. • The morphology and optical properties dependent on temperature are studied

Generalized inverses theory and computations

CERN Document Server

Wang, Guorong; Qiao, Sanzheng

2018-01-01

This book begins with the fundamentals of the generalized inverses, then moves to more advanced topics. It presents a theoretical study of the generalization of Cramer's rule, determinant representations of the generalized inverses, reverse order law of the generalized inverses of a matrix product, structures of the generalized inverses of structured matrices, parallel computation of the generalized inverses, perturbation analysis of the generalized inverses, an algorithmic study of the computational methods for the full-rank factorization of a generalized inverse, generalized singular value decomposition, imbedding method, finite method, generalized inverses of polynomial matrices, and generalized inverses of linear operators. This book is intended for researchers, postdocs, and graduate students in the area of the generalized inverses with an undergraduate-level understanding of linear algebra.

Hetero-epitaxial growth of TiC films on MgO(001) at 100 °C by DC reactive magnetron sputtering

International Nuclear Information System (INIS)

Braic, M.; Zoita, N.C.; Danila, M.; Grigorescu, C.E.A.; Logofatu, C.

2015-01-01

Hetero-epitaxial TiC thin films were deposited at 100 °C on MgO(001) by DC reactive magnetron sputtering in a mixture of Ar and CH 4 . The 62 nm thick films were analyzed for elemental composition and chemical bonding by Auger electron spectroscopy, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. The crystallographic structure investigation by high resolution X-ray diffraction revealed that the films consist of two layers: an interface partially strained epilayer with high crystalline quality, and a relaxed layer, formed by columnar grains, maintaining the epitaxial relationship with the substrate. The films presented smooth surfaces (RMS roughness ~ 0.55 nm), with circular equi-sized grains/crystallites, as observed by atomic force microscopy. The Hall measurements in Van der Pauw geometry revealed relatively high resistivity value ~ 620 μΩ cm, ascribed to electron scattering on interfaces, on grain boundaries and on different defects/dislocations. - Highlights: • Hetero-epitaxial TiC 0.84 thin films were grown on MgO(001) at 100 °C by magnetron sputtering. • 62 nm thick films were synthesized by magnetron sputtering, using Ti, Ar and CH 4 . • The film comprises a partially strained interface epilayer and a relaxed top layer. • Both layers preserve the epitaxial relationship with the substrate. • Low RMS surface roughness ~ 0.55 nm and grains with mean lateral size of ~ 38.5 nm were observed

Hetero-epitaxial growth of TiC films on MgO(001) at 100 °C by DC reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Braic, M. [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Zoita, N.C., E-mail: cnzoita@inoe.ro [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Danila, M. [National Institute for Research and Development in Microtechnology, 126A Erou Iancu Nicolae Blvd., 077190 Bucharest (Romania); Grigorescu, C.E.A. [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Logofatu, C. [National Institute of Materials Physics, 105 bis Atomistilor St., 077125 Magurele (Romania)

2015-08-31

Hetero-epitaxial TiC thin films were deposited at 100 °C on MgO(001) by DC reactive magnetron sputtering in a mixture of Ar and CH{sub 4}. The 62 nm thick films were analyzed for elemental composition and chemical bonding by Auger electron spectroscopy, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. The crystallographic structure investigation by high resolution X-ray diffraction revealed that the films consist of two layers: an interface partially strained epilayer with high crystalline quality, and a relaxed layer, formed by columnar grains, maintaining the epitaxial relationship with the substrate. The films presented smooth surfaces (RMS roughness ~ 0.55 nm), with circular equi-sized grains/crystallites, as observed by atomic force microscopy. The Hall measurements in Van der Pauw geometry revealed relatively high resistivity value ~ 620 μΩ cm, ascribed to electron scattering on interfaces, on grain boundaries and on different defects/dislocations. - Highlights: • Hetero-epitaxial TiC{sub 0.84} thin films were grown on MgO(001) at 100 °C by magnetron sputtering. • 62 nm thick films were synthesized by magnetron sputtering, using Ti, Ar and CH{sub 4}. • The film comprises a partially strained interface epilayer and a relaxed top layer. • Both layers preserve the epitaxial relationship with the substrate. • Low RMS surface roughness ~ 0.55 nm and grains with mean lateral size of ~ 38.5 nm were observed.

Effects of H2/O2 mixed gas plasma treatment on electrical and optical property of indium tin oxide

International Nuclear Information System (INIS)

Kim, Jun Young; Lee, Dong-Min; Kim, Jae-Kwan; Yang, Su-Hwan; Lee, Ji-Myon

2013-01-01

Highlights: ► The specific resistivity of ITO was enhanced by H 2 + O 2 mixed gas plasma treatment. ► The transmittance was same as that of untreated ITO after plasma treatment. ► The process was carried out at room temperature without any step of post-treatment. - Abstract: This study examined the effects of H 2 and H 2 + O 2 mixed gas plasma treatment on the properties of ITO films. The films were deposited on corning glass by RF magnetron sputtering under Ar and Ar/O 2 mixed gas ambient. After a H 2 plasma treatment, the ITO films showed an improved specific resistance due to the formation of oxygen vacancies acting as shallow donors, but showed quenched transmittance due to the formation of agglomerated metals on the surface. After an H 2 + O 2 mixed gas plasma treatment, the specific resistance of the film was improved without deteriorating transmittance. The enhanced specific resistance by mixed gas plasma treatment was attributed to the formation of free electrons by the incorporation of H in the lattice.

Some results on inverse scattering

International Nuclear Information System (INIS)

Ramm, A.G.

2008-01-01

A review of some of the author's results in the area of inverse scattering is given. The following topics are discussed: (1) Property C and applications, (2) Stable inversion of fixed-energy 3D scattering data and its error estimate, (3) Inverse scattering with 'incomplete' data, (4) Inverse scattering for inhomogeneous Schroedinger equation, (5) Krein's inverse scattering method, (6) Invertibility of the steps in Gel'fand-Levitan, Marchenko, and Krein inversion methods, (7) The Newton-Sabatier and Cox-Thompson procedures are not inversion methods, (8) Resonances: existence, location, perturbation theory, (9) Born inversion as an ill-posed problem, (10) Inverse obstacle scattering with fixed-frequency data, (11) Inverse scattering with data at a fixed energy and a fixed incident direction, (12) Creating materials with a desired refraction coefficient and wave-focusing properties. (author)

A Joint Method of Envelope Inversion Combined with Hybrid-domain Full Waveform Inversion

Science.gov (United States)

CUI, C.; Hou, W.

2017-12-01

Full waveform inversion (FWI) aims to construct high-precision subsurface models by fully using the information in seismic records, including amplitude, travel time, phase and so on. However, high non-linearity and the absence of low frequency information in seismic data lead to the well-known cycle skipping problem and make inversion easily fall into local minima. In addition, those 3D inversion methods that are based on acoustic approximation ignore the elastic effects in real seismic field, and make inversion harder. As a result, the accuracy of final inversion results highly relies on the quality of initial model. In order to improve stability and quality of inversion results, multi-scale inversion that reconstructs subsurface model from low to high frequency are applied. But, the absence of very low frequencies (time domain and inversion in the frequency domain. To accelerate the inversion, we adopt CPU/GPU heterogeneous computing techniques. There were two levels of parallelism. In the first level, the inversion tasks are decomposed and assigned to each computation node by shot number. In the second level, GPU multithreaded programming is used for the computation tasks in each node, including forward modeling, envelope extraction, DFT (discrete Fourier transform) calculation and gradients calculation. Numerical tests demonstrated that the combined envelope inversion + hybrid-domain FWI could obtain much faithful and accurate result than conventional hybrid-domain FWI. The CPU/GPU heterogeneous parallel computation could improve the performance speed.

CdSe Nanoparticles with Clean Surfaces: Gas Phase Synthesis and Optical Properties

Directory of Open Access Journals (Sweden)

Zhang Hongwei

2015-01-01

Full Text Available CdSe nanoparticles (NPs were generated in gas phase with a magnetron plasma gas aggregation cluster beam source. Coagulation-free CdSe nanocrystals with very clean particle surface and interface, as well as a fairly uniform spatial distribution were obtained. The deposited NPs have a good dispersity with a mean diameter of about 4.8nm. A strong photoluminescence band corresponding to the near- band-edge transition of the CdSe NPs was observed. The CdSe NP films show a significant photoconductance induced by laser irradiation. With an applied bias voltage of 10V, the photo- induced current can be as high as 0.4mA under 0.01mW/mm2 405nm laser illumination. Our approach offers an alternative method for CdSe NP synthesis, which has the advantages such as high purity, good process and product control, as well as mass production, as compared to the existing methods.

Properties of nickel films growth by radio frequency magnetron sputtering at elevated substrate temperatures

Energy Technology Data Exchange (ETDEWEB)

Muslim, Noormariah, E-mail: 14h8702@ubd.edu.bn [Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410 (Brunei Darussalam); Soon, Ying Woan [Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410 (Brunei Darussalam); Physical and Geological Sciences, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410 (Brunei Darussalam); Lim, Chee Ming; Voo, Nyuk Yoong [Centre for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE1410 (Brunei Darussalam)

2016-08-01

Pure nickel (Ni) thin films of thicknesses of 100 nm were deposited on glass substrates by radio frequency magnetron sputtering at a power of 100 W and at various substrate temperatures i.e., room temperature, 100, 200, and 300 °C. The crystalline structure, surface topography, surface morphology, electrical resistivity, and optical properties of the deposited films were studied. The properties of the Ni films could be controlled by altering the substrate temperature. Specifically, the films featured a face-centered cubic crystalline structure with predominant (111) crystallite orientation at all the substrate temperatures employed, as observed from the X-ray diffraction analysis. Films deposited at substrate temperatures greater than 200 °C additionally displayed crystalline (200) and (220) diffraction peaks. The surface morphology analysis revealed that the grain size of the Ni thin films increased with increasing substrate temperatures employed. This increase was accompanied with a decrease in the resistivity of the Ni films. The surface roughness of the films increased with increasing substrate temperatures employed, as observed from the atomic force microscopy analysis. - Highlights: • RF magnetron sputtering is a good alternative method to deposit Ni films. • Properties of Ni films could be controlled simply by tuning substrate temperatures. • Crystallite size and surface roughness increased with substrate temperatures. • Electrical resistivity reduced with increasing substrate temperatures. • Optical properties also changed with substrate temperatures.

Electrical and Optical Properties of Fluorine Doped Tin Oxide Thin Films Prepared by Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Ziad Y. Banyamin

2014-10-01

Full Text Available Fluorine doped tin oxide (FTO coatings have been prepared using the mid-frequency pulsed DC closed field unbalanced magnetron sputtering technique in an Ar/O2 atmosphere using blends of tin oxide and tin fluoride powder formed into targets. FTO coatings were deposited with a thickness of 400 nm on glass substrates. No post-deposition annealing treatments were carried out. The effects of the chemical composition on the structural (phase, grain size, optical (transmission, optical band-gap and electrical (resistivity, charge carrier, mobility properties of the thin films were investigated. Depositing FTO by magnetron sputtering is an environmentally friendly technique and the use of loosely packed blended powder targets gives an efficient means of screening candidate compositions, which also provides a low cost operation. The best film characteristics were achieved using a mass ratio of 12% SnF2 to 88% SnO2 in the target. The thin film produced was polycrystalline with a tetragonal crystal structure. The optimized conditions resulted in a thin film with average visible transmittance of 83% and optical band-gap of 3.80 eV, resistivity of 6.71 × 10−3 Ω·cm, a carrier concentration (Nd of 1.46 × 1020 cm−3 and a mobility of 15 cm2/Vs.

Type II textured molybdenum disulphide films produced by direct vapour transport and rf-magnetron sputtering

International Nuclear Information System (INIS)

Bohlken, S.F.; Lemon, K.D.; Jakovidis, G.; Taheri, E.H.

1999-01-01

Full text: Molybdenum disulphide (MoS 2 ) is one of the few naturally occurring Layered Transition Metal Dichalcogenides and is the primary source for elemental molybdenum. It displays exceptional lubrication performance in both vacuum and atmospheric conditions over a wide temperature range. An important emerging application of MoS 2 and related materials is photovoltaics. Films of MoS 2 exhibit several morphologies described by the orientation of platelets with respect to the substrate. Films with platelets perpendicular or parallel to the substrate are referred to by their morphology, which is type-I or type-II respectively. Production of exclusive type-II films is highly desirable in applications involving lubrication and photovoltaics. For example, type-II morphology reduces friction and minority carrier recombination centres, thus improving tribological and photovoltaic performance. We have successfully produced type-II films using both direct vapour transport and rf-magnetron sputtering Continuous polycrystalline films (∼ 10 μm thick) grown in our laboratory using vapour transport have typical areas 1000 mm 2 . A novel ejecta filtration technique was applied to rf-magnetron sputtering. Films produced using this approach retain exclusive type-II morphology at thicknesses where type-I would normally be observed (∼ 200nm)

Calculation of the inverse data space via sparse inversion

KAUST Repository

Saragiotis, Christos; Doulgeris, Panagiotis C.; Verschuur, Dirk Jacob Eric

2011-01-01

The inverse data space provides a natural separation of primaries and surface-related multiples, as the surface multiples map onto the area around the origin while the primaries map elsewhere. However, the calculation of the inverse data is far from

Eruption mass estimation using infrasound waveform inversion and ash and gas measurements: Evaluation at Sakurajima Volcano, Japan [Comparison of eruption masses at Sakurajima Volcano, Japan calculated by infrasound waveform inversion and ground-based sampling

International Nuclear Information System (INIS)

Fee, David; Izbekov, Pavel; Kim, Keehoon; Yokoo, Akihiko; Lopez, Taryn

2017-01-01

Eruption mass and mass flow rate are critical parameters for determining the aerial extent and hazard of volcanic emissions. Infrasound waveform inversion is a promising technique to quantify volcanic emissions. Although topography may substantially alter the infrasound waveform as it propagates, advances in wave propagation modeling and station coverage permit robust inversion of infrasound data from volcanic explosions. The inversion can estimate eruption mass flow rate and total eruption mass if the flow density is known. However, infrasound-based eruption flow rates and mass estimates have yet to be validated against independent measurements, and numerical modeling has only recently been applied to the inversion technique. Furthermore we present a robust full-waveform acoustic inversion method, and use it to calculate eruption flow rates and masses from 49 explosions from Sakurajima Volcano, Japan.

Inverse Limits

CERN Document Server

Ingram, WT

2012-01-01

Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

Comparison of Dorris-Gray and Schultz methods for the calculation of surface dispersive free energy by inverse gas chromatography.

Science.gov (United States)

Shi, Baoli; Wang, Yue; Jia, Lina

2011-02-11

Inverse gas chromatography (IGC) is an important technique for the characterization of surface properties of solid materials. A standard method of surface characterization is that the surface dispersive free energy of the solid stationary phase is firstly determined by using a series of linear alkane liquids as molecular probes, and then the acid-base parameters are calculated from the dispersive parameters. However, for the calculation of surface dispersive free energy, generally, two different methods are used, which are Dorris-Gray method and Schultz method. In this paper, the results calculated from Dorris-Gray method and Schultz method are compared through calculating their ratio with their basic equations and parameters. It can be concluded that the dispersive parameters calculated with Dorris-Gray method will always be larger than the data calculated with Schultz method. When the measuring temperature increases, the ratio increases large. Compared with the parameters in solvents handbook, it seems that the traditional surface free energy parameters of n-alkanes listed in the papers using Schultz method are not enough accurate, which can be proved with a published IGC experimental result. © 2010 Elsevier B.V. All rights reserved.

Inverse problems of geophysics

International Nuclear Information System (INIS)

Yanovskaya, T.B.

2003-07-01

This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

Acute puerperal uterine inversion

International Nuclear Information System (INIS)

Hussain, M.; Liaquat, N.; Noorani, K.; Bhutta, S.Z; Jabeen, T.

2004-01-01

Objective: To determine the frequency, causes, clinical presentations, management and maternal mortality associated with acute puerperal inversion of the uterus. Materials and Methods: All the patients who developed acute puerperal inversion of the uterus either in or outside the JPMC were included in the study. Patients of chronic uterine inversion were not included in the present study. Abdominal and vaginal examination was done to confirm and classify inversion into first, second or third degrees. Results: 57036 deliveries and 36 acute uterine inversions occurred during the study period, so the frequency of uterine inversion was 1 in 1584 deliveries. Mismanagement of third stage of labour was responsible for uterine inversion in 75% of patients. Majority of the patients presented with shock, either hypovolemic (69%) or neurogenic (13%) in origin. Manual replacement of the uterus under general anaesthesia with 2% halothane was successfully done in 35 patients (97.5%). Abdominal hysterectomy was done in only one patient. There were three maternal deaths due to inversion. Conclusion: Proper education and training regarding placental delivery, diagnosis and management of uterine inversion must be imparted to the maternity care providers especially to traditional birth attendants and family physicians to prevent this potentially life-threatening condition. (author)

Magnetron deposition of metal-ceramic protective coatings on glasses of windows of space vehicles

OpenAIRE

Sergeev, Viktor Petrovich; Panin, Viktor Evgenyevich; Psakhie, Sergey Grigorievich; Chernyavskii, Alexandr; Svechkin, Valerii; Khristenko, Yurii; Kalashnikov, Mark Petrovich; Voronov, Andrei

2014-01-01

Transparent refractory metal-ceramic nanocomposite coatings with a high coefficient of elasticrecovery and microhardness on the basis of Ni/Si-Al-N are formed on a glass substrate by the pulse magnetron deposition method. The structure-phase states were investigated by TEM, SEM. It was established that the first layer consists of Ni nanograins with a fcc crystalline lattice, the second layer is two-phase: 5-10 nm nanocrystallites of the AlN phase with the hcp crystalline lattice in amorphous ...

Improving the Tribological Properties of Spark-Anodized Titanium by Magnetron Sputtered Diamond-Like Carbon

OpenAIRE

Zhaoxiang Chen; Xipeng Ren; Limei Ren; Tengchao Wang; Xiaowen Qi; Yulin Yang

2018-01-01

Spark-anodization of titanium can produce adherent and wear-resistant TiO2 film on the surface, but the spark-anodized titanium has lots of surface micro-pores, resulting in an unstable and high friction coefficient against many counterparts. In this study, the diamond-like carbon (DLC) was introduced into the micro-pores of spark-anodized titanium by the magnetron sputtering technique and a TiO2/DLC composite coating was fabricated. The microstructure and tribological properties of TiO2/DLC ...

Reactive magnetron sputtering deposition of bismuth tungstate onto titania nanoparticles for enhancing visible light photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Ratova, Marina, E-mail: marina_ratova@hotmail.com [Surface Engineering Group, School of Engineering, Manchester Metropolitan University, Manchester, M1 5GD (United Kingdom); Kelly, Peter J.; West, Glen T. [Surface Engineering Group, School of Engineering, Manchester Metropolitan University, Manchester, M1 5GD (United Kingdom); Tosheva, Lubomira; Edge, Michele [School of Science and the Environment, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)

2017-01-15

Highlights: • Bismuth tungstate coatings were deposited by reactive magnetron sputtering. • Oscillating bowl was introduced to the system to enable coating of nanopartulates. • Deposition of Bi{sub 2}WO{sub 6} enhanced visible light activity of titania nanoparticles. • The best results were obtained for coating with Bi:W ratio of approximately 2:1. • Deposition of Bi{sub 2}WO{sub 6} onto TiO{sub 2} resulted in more efficient electron-hole separation. - Abstract: Titanium dioxide − bismuth tungstate composite materials were prepared by pulsed DC reactive magnetron sputtering of bismuth and tungsten metallic targets in argon/oxygen atmosphere onto anatase and rutile titania nanoparticles. The use of an oscillating bowl placed beneath the two magnetrons arranged in a co-planar closed field configuration enabled the deposition of bismuth tungstate onto loose powders, rather than a solid substrate. The atomic ratio of the bismuth/tungsten coatings was controlled by varying the power applied to each target. The effect of the bismuth tungstate coatings on the phase, optical and photocatalytic properties of titania was investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) surface area measurements, transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy and an acetone degradation test. The latter involved measurements of the rate of CO{sub 2} evolution under visible light irradiation of the photocatalysts, which indicated that the deposition of bismuth tungstate resulted in a significant enhancement of visible light activity, for both anatase and rutile titania particles. The best results were achieved for coatings with a bismuth to tungsten atomic ratio of 2:1. In addition, the mechanism by which the photocatalytic activity of the TiO{sub 2} nanoparticles was enhanced by compounding it with bismuth tungstate was studied by microwave cavity perturbation. The results of these

Inverse feasibility problems of the inverse maximum flow problems

Indian Academy of Sciences (India)

199–209. c Indian Academy of Sciences. Inverse feasibility problems of the inverse maximum flow problems. ADRIAN DEACONU. ∗ and ELEONOR CIUREA. Department of Mathematics and Computer Science, Faculty of Mathematics and Informatics, Transilvania University of Brasov, Brasov, Iuliu Maniu st. 50,. Romania.

Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates

Energy Technology Data Exchange (ETDEWEB)

Brennan, Christopher J.; Neumann, Christopher M.; Vitale, Steven A., E-mail: steven.vitale@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

2015-07-28

Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was markedly better for PE-ALD TiN. A significant reduction in interface state density was inferred from capacitance-voltage measurements as well as a 1200× reduction in gate leakage current. A high-power magnetron plasma source produces a much higher energetic ion and vacuum ultra-violet (VUV) photon flux to the wafer compared to a low-power inductively coupled PE-ALD source. The ion and VUV photons produce defect states in the bulk of the gate oxide as well as at the oxide-silicon interface, causing higher leakage and potential reliability degradation.

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)

Magnetron injection gun for a broadband gyrotron backward-wave oscillator

International Nuclear Information System (INIS)

Yuan, C. P.; Chang, T. H.; Chen, N. C.; Yeh, Y. S.

2009-01-01

The magnetron injection gun is capable of generating relativistic electron beam with high velocity ratio and low velocity spread for a gyrotron backward-wave oscillator (gyro-BWO). However, the velocity ratio (α) varies drastically against both the magnetic field and the beam voltage, which significantly limits the tuning bandwidth of a gyro-BWO. This study remedies this drawback by adding a variable trim field to adjust the magnetic compression ratio when changing the operating conditions. Theoretical results obtained by employing a two-dimensional electron gun code (EGUN) demonstrate a constant velocity ratio of 1.5 with a low axial velocity spread of 6% from 3.4-4.8 Tesla. These results are compared with a three-dimensional particle-tracing code (computer simulation technology, CST). The underlying physics for constant α will be discussed in depth.

Magnetron injection gun for a broadband gyrotron backward-wave oscillator

Science.gov (United States)

Yuan, C. P.; Chang, T. H.; Chen, N. C.; Yeh, Y. S.

2009-07-01

The magnetron injection gun is capable of generating relativistic electron beam with high velocity ratio and low velocity spread for a gyrotron backward-wave oscillator (gyro-BWO). However, the velocity ratio (α) varies drastically against both the magnetic field and the beam voltage, which significantly limits the tuning bandwidth of a gyro-BWO. This study remedies this drawback by adding a variable trim field to adjust the magnetic compression ratio when changing the operating conditions. Theoretical results obtained by employing a two-dimensional electron gun code (EGUN) demonstrate a constant velocity ratio of 1.5 with a low axial velocity spread of 6% from 3.4-4.8 Tesla. These results are compared with a three-dimensional particle-tracing code (computer simulation technology, CST). The underlying physics for constant α will be discussed in depth.

Synthesis of ReN3 Thin Films by Magnetron Sputtering

Directory of Open Access Journals (Sweden)

G. Soto

2014-01-01

Full Text Available In this work ReNx films were prepared by reactive magnetron sputtering at room temperature and deposited on a silicon wafer. It was found that the diffractograms of the nitrogen-rich rhenium film are consistent with those produced by high-pressure high-temperature methods, under the assumption that the film is oriented on the substrate. Using density functional calculations it was found that the composition of this compound could be ReN3, instead of ReN2, as stated on previous works. The ReN3 compound fits in the Ama2 (40 orthorhombic space group, and due to the existence of N3 anions between Re layers it should be categorized as an azide. The material is exceptionally brittle and inherently unstable under indentation testing.

Direct current magnetron sputter-deposited ZnO thin films

International Nuclear Information System (INIS)

Hoon, Jian-Wei; Chan, Kah-Yoong; Krishnasamy, Jegenathan; Tou, Teck-Yong; Knipp, Dietmar

2011-01-01

Zinc oxide (ZnO) is a very promising electronic material for emerging transparent large-area electronic applications including thin-film sensors, transistors and solar cells. We fabricated ZnO thin films by employing direct current (DC) magnetron sputtering deposition technique. ZnO films with different thicknesses ranging from 150 nm to 750 nm were deposited on glass substrates. The deposition pressure and the substrate temperature were varied from 12 mTorr to 25 mTorr, and from room temperature to 450 deg. C, respectively. The influence of the film thickness, deposition pressure and the substrate temperature on structural and optical properties of the ZnO films was investigated using atomic force microscopy (AFM) and ultraviolet-visible (UV-Vis) spectrometer. The experimental results reveal that the film thickness, deposition pressure and the substrate temperature play significant role in the structural formation and the optical properties of the deposited ZnO thin films.

Fractal features of CdTe thin films grown by RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Hosseinpanahi, Fayegh, E-mail: f.hosseinpanahi@yahoo.com [Department of Physics, Payame Noor University, P.O. Box 19395-4697, Tehran (Iran, Islamic Republic of); Raoufi, Davood [Department of Physics, University of Bu Ali Sina, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Ranjbarghanei, Khadijeh [Department of Physics, Plasma Physics Research Center, Science & Research Branch Islamic Azad University, Tehran (Iran, Islamic Republic of); Karimi, Bayan [Department of Physics, Payame Noor University, P.O. Box 19395-4697, Tehran (Iran, Islamic Republic of); Babaei, Reza [Department of Physics, Plasma Physics Research Center, Science & Research Branch Islamic Azad University, Tehran (Iran, Islamic Republic of); Hasani, Ebrahim [Department of Physics, University of Bu Ali Sina, P.O. Box 65174, Hamedan (Iran, Islamic Republic of)

2015-12-01

Graphical abstract: - Highlights: • CdTe thin films were deposited on glass substrates by RF magnetron sputtering at room temperature with different deposition time 5, 10 and 15 min. • Nanostructure of CdTe layer indicates that CdTe films are polycrystalline and have zinc blende structure, irrespective of their deposition time. • Complexity and roughness of the CdTe films and strength of multifractality increase with increasing deposition time. • Detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe films have multifractal nature. - Abstract: Cadmium telluride (CdTe) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature (RT). The film deposition was performed for 5, 10, and 15 min at power of 30 W with a frequency of 13.56 MHz. The crystal structure of the prepared CdTe thin films was studied by X-ray diffraction (XRD) technique. XRD analyses indicate that the CdTe films are polycrystalline, having zinc blende structure of CdTe irrespective of their deposition time. All CdTe films showed a preferred orientation along (1 1 1) crystalline plane. The surface morphology characterization of the films was studied using atomic force microscopy (AFM). The quantitative AFM characterization shows that the RMS surface roughness of the prepared CdTe thin films increases with increasing the deposition time. The detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe thin films have multifractal nature. The complexity, roughness of the CdTe thin films and strength of the multifractality increase as deposition time increases.

Fractal features of CdTe thin films grown by RF magnetron sputtering

International Nuclear Information System (INIS)

Hosseinpanahi, Fayegh; Raoufi, Davood; Ranjbarghanei, Khadijeh; Karimi, Bayan; Babaei, Reza; Hasani, Ebrahim

2015-01-01

Graphical abstract: - Highlights: • CdTe thin films were deposited on glass substrates by RF magnetron sputtering at room temperature with different deposition time 5, 10 and 15 min. • Nanostructure of CdTe layer indicates that CdTe films are polycrystalline and have zinc blende structure, irrespective of their deposition time. • Complexity and roughness of the CdTe films and strength of multifractality increase with increasing deposition time. • Detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe films have multifractal nature. - Abstract: Cadmium telluride (CdTe) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature (RT). The film deposition was performed for 5, 10, and 15 min at power of 30 W with a frequency of 13.56 MHz. The crystal structure of the prepared CdTe thin films was studied by X-ray diffraction (XRD) technique. XRD analyses indicate that the CdTe films are polycrystalline, having zinc blende structure of CdTe irrespective of their deposition time. All CdTe films showed a preferred orientation along (1 1 1) crystalline plane. The surface morphology characterization of the films was studied using atomic force microscopy (AFM). The quantitative AFM characterization shows that the RMS surface roughness of the prepared CdTe thin films increases with increasing the deposition time. The detrended fluctuation analysis (DFA) and also multifractal detrended fluctuation analysis (MFDFA) methods showed that prepared CdTe thin films have multifractal nature. The complexity, roughness of the CdTe thin films and strength of the multifractality increase as deposition time increases.

A global plasma model for reactive deposition of compound films by modulated pulsed power magnetron sputtering discharges

Science.gov (United States)

Zheng, B. C.; Wu, Z. L.; Wu, B.; Li, Y. G.; Lei, M. K.

2017-05-01

A spatially averaged, time-dependent global plasma model has been developed to describe the reactive deposition of a TiAlSiN thin film by modulated pulsed power magnetron sputtering (MPPMS) discharges in Ar/N2 mixture gas, based on the particle balance and the energy balance in the ionization region, and considering the formation and erosion of the compound at the target surface. The modeling results show that, with increasing the N2 partial pressure from 0% to 40% at a constant working pressure of 0.3 Pa, the electron temperature during the strongly ionized period increases from 4 to 7 eV and the effective power transfer coefficient, which represents the power fraction that effectively heats the electrons and maintains the discharge, increases from about 4% to 7%; with increasing the working pressure from 0.1 to 0.7 Pa at a constant N2 partial pressure of 25%, the electron temperature decreases from 10 to 4 eV and the effective power transfer coefficient decreases from 8% to 5%. Using the modeled plasma parameters to evaluate the kinetic energy of arriving ions, the ion-to-neutral flux ratio of deposited species, and the substrate heating, the variations of process parameters that increase these values lead to an enhanced adatom mobility at the target surface and an increased input energy to the substrate, corresponding to the experimental observation of surface roughness reduction, the microstructure transition from the columnar structure to the dense featureless structure, and the enhancement of phase separation. At higher N2 partial pressure or lower working pressure, the modeling results demonstrate an increase in electron temperature, which shifts the discharge balance of Ti species from Ti+ to Ti2+ and results in a higher return fraction of Ti species, corresponding to the higher Al/Ti ratio of deposited films at these conditions. The modeling results are well correlated with the experimental observation of the composition variation and the microstructure

Seismic characterization of hydrates in faulted, fine-grained sediments of Krishna-Godavari basin: Full waveform inversion.

Digital Repository Service at National Institute of Oceanography (India)

Jaiswal, P.; Dewangan, P.; Ramprasad, T.; Zelt, C.A.

(QP−1) character of the gas hydrate stability zone (GHSZ). In this paper, we apply frequency domain full-waveform inversion (FWI) to surface-towed 2D multichannel seismic data from the Krishna-Godavari (KG) Basin, India, to image the fine-scale (100...

Inverse analyses of effective diffusion parameters relevant for a two-phase moisture model of cementitious materials

DEFF Research Database (Denmark)

Addassi, Mouadh; Johannesson, Björn; Wadsö, Lars

2018-01-01

Here we present an inverse analyses approach to determining the two-phase moisture transport properties relevant to concrete durability modeling. The purposed moisture transport model was based on a continuum approach with two truly separate equations for the liquid and gas phase being connected...... test, and, (iv) capillary suction test. Mass change over time, as obtained from the drying test, the two different cup test intervals and the capillary suction test, was used to obtain the effective diffusion parameters using the proposed inverse analyses approach. The moisture properties obtained...

Spin-charge conversion in disordered two-dimensional electron gases lacking inversion symmetry

Science.gov (United States)

Huang, Chunli; Milletarı, Mirco; Cazalilla, Miguel A.

2017-11-01

We study the spin-charge conversion mechanisms in a two-dimensional gas of electrons moving in a smooth disorder potential by accounting for both Rashba-type and Mott's skew scattering contributions. We find that the quantum interference effects between spin-flip and skew scattering give rise to anisotropic spin precession scattering (ASP), a direct spin-charge conversion mechanism that was discovered in an earlier study of graphene decorated with adatoms [Huang et al., Phys. Rev. B 94, 085414 (2016), 10.1103/PhysRevB.94.085414]. Our findings suggest that, together with other spin-charge conversion mechanisms such as the inverse galvanic effect, ASP is a fairly universal phenomenon that should be present in disordered two-dimensional systems lacking inversion symmetry.

125 MeV Si 9+ ion irradiation of calcium phosphate thin film coated by rf-magnetron sputtering technique

Science.gov (United States)

Elayaraja, K.; Joshy, M. I. Ahymah; Suganthi, R. V.; Kalkura, S. Narayana; Palanichamy, M.; Ashok, M.; Sivakumar, V. V.; Kulriya, P. K.; Sulania, I.; Kanjilal, D.; Asokan, K.

2011-01-01

Titanium substrate was coated with hydroxyapatite by radiofrequency magnetron sputtering (rf-magnetron sputtering) technique and subjected to swift heavy ion (SHI) irradiation of 125 MeV with Si 9+ at fluences of 1 × 10 10, 1 × 10 11 and 1 × 10 12 ions/cm 2. The glancing incidence X-ray diffraction (GIXRD) analysis confirmed the HAp phase of the irradiated film. There was a considerable decrease in crystallinity and particle size after irradiation. In addition, DRS-UV reflectance spectra revealed a decrease in optical band gap ( Eg) from 5.2 to 4.6 eV. Wettability of biocompatible materials plays an important role in biological cells proliferation for tissue engineering, drug delivery, gene transfer and bone growth. HAp thin films irradiated with 1 × 10 11 ions/cm 2 fluence showed significant increase in wettability. While the SHI irradiated samples exhibited enhanced bioactivity, there was no significant variation in cell viability. Surface roughness, pores and average particle size were analyzed by atomic force microscopy (AFM).

Recent Developments in R.F. Magnetron Sputtered Thin Films for pH Sensing Applications—An Overview

OpenAIRE

D. K. Maurya; A. Sardarinejad; K. Alameh

2014-01-01

pH sensors are widely used in chemical and biological applications. Metal oxides-based pH sensors have many attractive features including insolubility, stability, mechanical strength, electrocatalyst and manufacturing technology. Various metal oxide thin films prepared by radio frequency (R.F.) magnetron sputtering have attractive features, including high pH sensitivity, fast response, high resolution, good stability and reversibility as well as potential for measuring pH under conditions th...

Turbostratic-like carbon nitride coatings deposited by industrial-scale direct current magnetron sputtering

International Nuclear Information System (INIS)

Louring, S.; Madsen, N.D.; Berthelsen, A.N.; Christensen, B.H.; Almtoft, K.P.; Nielsen, L.P.; Bøttiger, J.

2013-01-01

Carbon nitride thin films were deposited by direct current magnetron sputtering in an industrial-scale equipment at different deposition temperatures and substrate bias voltages. The films had N/(N + C) atomic fractions between 0.2 and 0.3 as determined by X-ray photoelectron spectroscopy (XPS). Raman spectroscopy provided insight into the ordering and extension of the graphite-like clusters, whereas nanoindentation revealed information on the mechanical properties of the films. The internal compressive film stress was evaluated from the substrate bending method. At low deposition temperatures the films were amorphous, whereas the film deposited at approximately 380 °C had a turbostratic-like structure as confirmed by high-resolution transmission electron microscopy images. The turbostratic-like film had a highly elastic response when subjected to nanoindentation. When a CrN interlayer was deposited between the film and the substrate, XPS and Raman spectroscopy indicated that the turbostratic-like structure was maintained. However, it was inconclusive whether the film still exhibited an extraordinary elastic recovery. An increased substrate bias voltage, without additional heating and without deposition of an interlayer, resulted in a structural ordering, although not to the extent of a turbostratic-like structure. - Highlights: • Carbon nitride films were deposited by industrial-scale magnetron sputtering. • The deposition temperature and the substrate bias voltage were varied. • A turbostratic-like structure was obtained at an elevated deposition temperature. • The turbostratic-like film exhibited a very high elastic recovery. • The influence of a CrN interlayer on the film properties was investigated

Seismic characterization of hydrates in faulted, fine-grained sediments of Krishna-Godavari Basin: Full waveform inversion

Digital Repository Service at National Institute of Oceanography (India)

Jaiswal, P.; Dewangan, P.; Ramprasad, T.; Zelt, C.A.

(P)) and attenuation (Q sub(P) sup(-1)) character of the gas hydrate stability zone (GHSZ). In this paper, we apply frequency domain full-waveform inversion (FWI) to surface-towed 2D multichannel seismic data from the Krishna-Godavari (KG) Basin, India, to image...

Properties of tungsten films prepared by magnetron sputtering

International Nuclear Information System (INIS)

Ahn, K.Y.; Ting, C.Y.; Brodsky, S.B.; Fryer, P.M.; Davari, B.; Angillelo, J.; Herd, S.R.; Licata, T.

1986-01-01

High-rate magnetron sputtering is a relatively simple process to produce tungsten films with good electrical and mechanical properties, and it offers good uniformity, reproducibility, process flexibility, and high throughput. The purity of the sputtered films is affected by the target purity (cold-pressed 99.95%, chemical vapor deposited 99.99% and cast 99.999%), base pressure, deposition rate, and substrate bias. Typical resistivity in films of 2000 to 3000A thickness deposited on Si, poly-Si, and SiO/sub 2/ ranges from 10 to 12 μΩ-cm, and this may be compared with 6 and 11 μΩ-cm by high-temperature evaporation and chemical vapor deposition, respectively. The presence of biaxial stress caused by substrate scanning was determined by x-ray technique. The sputtered films exhibit high compressive stress when deposited at low Ar pressure. It decreases with increasing pressure, and eventually changes sign to become tensile, and increases further with increasing pressure. Effects of processing parameters on films properties, and a comparison of film properties prepared by evaporation and chemical vapor deposition are discussed

Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

Directory of Open Access Journals (Sweden)

S. Ars

2017-12-01

Full Text Available This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping

Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

Science.gov (United States)

Ars, Sébastien; Broquet, Grégoire; Yver Kwok, Camille; Roustan, Yelva; Wu, Lin; Arzoumanian, Emmanuel; Bousquet, Philippe

2017-12-01

This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances

Deposition of SiOx thin films on Y-TZP by reactive magnetron sputtering: influence of plasma parameters on the adhesion properties between Y-TZP and resin cement for application in dental prosthesis

Directory of Open Access Journals (Sweden)

José Renato Calvacanti de Queiroz

2011-01-01

Full Text Available In this paper SiOx thin films were deposited on Y-TZP ceramics by reactive magnetron sputtering technique in order to improve the adhesion properties between Y-TZP and resin cement for applications in dental prosthesis. For fixed cathode voltage, target current, working pressure and target-to-substrate distance, SiOx thin films were deposited at different oxygen concentrations in the Ar+O2 plasma forming gas. After deposition processes, SiOx thin films were characterized by profilometry, energy dispersive spectroscopy (EDS, optical microscopy and scanning electron microscopy (SEM. Adhesion properties between Y-TZP and resin cement were evaluated by shear testing. Results indicate that films deposited at 20%O2 increased the bond strength to (32.8 ± 5.4 MPa. This value has not been achieved by traditional methods.

Assessment of the thermodynamic properties of poly(2,2,2-trifluoroethyl methacrylate) by inverse gas chromatography.

Science.gov (United States)

Papadopoulou, Stella K; Panayiotou, Costas

2014-01-10

The thermodynamic properties of poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) were determined by the aid of the inverse gas chromatography technique (IGC), at infinite dilution. The interactions between the polymer and 15 solvents were examined in the temperature range of 120-150 °C via the estimation of the thermodynamic sorption parameters, the parameters of mixing at infinite dilution, the weight fraction activity coefficients and the Flory-Huggins interaction parameters. Additionally, the total and the partial solubility parameters of PTFEMA were estimated. The findings of this work indicate that the type and strength of the intermolecular interactions between the polymer and the solvents are strongly depended on the functional groups of the polymer and the solvents. The proton acceptor character of the polymer is responsible for the preferential solubility of PTFEMA in chloroform which acts as a proton donor solvent. The results also reveal that the polymer is insoluble in alkanes and alcohols whereas it presents good miscibility with polar solvents, especially with 2-butanone, 2-pentanone and 1,4-dioxane. Furthermore, the total and dispersive solubility parameters appear diminishing upon temperature rise, whereas the opposite behavior is noticed for the polar and hydrogen bonding solubility parameters. The latter increase with temperature, probably, due to conformational changes of the polymer on the solid support. Finally, comparison of the solubilization profiles of fluorinated methacrylic polymers studied by IGC, leads to the conclusion that PTFEMA is more soluble compared to polymers with higher fluorine content. Copyright © 2013 Elsevier B.V. All rights reserved.

Deposition of indium tin oxide films on acrylic substrates by radiofrequency magnetron sputtering

International Nuclear Information System (INIS)

Chiou, B.S.; Hsieh, S.T.; Wu, W.F.

1994-01-01

Indium tin oxide (ITO) films were deposited onto acrylic substrates by rf magnetron sputtering. Low substrate temperature (< 80 C) and low rf power (< 28 W) were maintained during sputtering to prevent acrylic substrate deformation. The influence of sputtering parameters, such as rf power, target-to-substrate distance, and chamber pressure, on the film deposition rate, the electrical properties, as well as the optical properties of the deposited films was investigated. Both the refractive index and the extinction coefficient were derived. The high reflection at wavelengths greater than 3 μm made these sputtered ITO films applicable to infrared mirrors

Applying RF Magnetron sputtering to prepare ZnO thin films and their characterization

International Nuclear Information System (INIS)

Saad, M.; Kassis, A.

2009-05-01

ZnO thin films were prepared using Rf magnetron sputtering under several preparation conditions (different values of deposition pressure, Rf power, substrate temperature). The optical properties of these films were investigated by measuring their transmission in the spectral range (300-1000 nm), and the electrical properties were investigated by measuring their electrical resistance. Results have been discussed in terms of the modified Thornton model for sputtered thin metal oxide films. Preparation conditions for depositing the highly resistive transparent i-ZnO buffer layer and the highly conducting transparent n-ZnO window layer for solar cells were proposed. (author)

Highly -oriented growth of polycrystalline silicon films on glass by pulsed magnetron sputtering

International Nuclear Information System (INIS)

Reinig, P.; Selle, B.; Fenske, F.; Fuhs, W.; Alex, V.; Birkholz, M.

2002-01-01

Nominally undoped polycrystalline silicon (poly-Si) thin films were deposited on glass at 450 deg. C at high deposition rate (>100 nm/min) by pulsed dc magnetron sputtering. The pulse frequency was found to have a significant influence on the preferred grain orientation. The x-ray diffraction pattern exhibits a strong enhancement of the (400) reflex with increasing pulse frequency. The quantitative evaluation reveals that over 90% of the grains are oriented. The observed change in preferred grain orientation in poly-Si films at low temperatures is associated with concurrent ion bombardment of the growing film

Effect of annealing on the mechanical and scratch properties of BCN films obtained by magnetron sputtering deposition

Energy Technology Data Exchange (ETDEWEB)

Xu, Shuyan, E-mail: xsynefu@126.com [Key Laboratory of Forest Sustainable Management and Environmental Microorganism Engineering of Heilongjiang Province, Northeast Forestry University, Harbin 150040 (China); Ma, Xinxin [School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wen, Huiying [Key Laboratory of Forest Sustainable Management and Environmental Microorganism Engineering of Heilongjiang Province, Northeast Forestry University, Harbin 150040 (China); Tang, Guangze [School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Li, Chunwei [Key Laboratory of Forest Sustainable Management and Environmental Microorganism Engineering of Heilongjiang Province, Northeast Forestry University, Harbin 150040 (China)

2014-09-15

Highlights: • The amorphous BCN films were annealed at different temperatures under vacuum condition. • The order degree increases with the annealing temperature increasing, and the films do not decompose even the annealing temperature rise to 1000 °C. • The nano-hardness and modulus of the films decrease with the increasing of annealing temperatures. • The critical load of BCN films is not affected by the annealing temperature, and the films have good interfacial adhesion. • The scratch resistance properties of BCN film are improved by annealing at 600 °C. - Abstract: Boron-carbon-nitride (BCN) films have been fabricated by direct current unbalanced magnetron sputtering. Boron carbide/graphite compound and a mixture of nitrogen and argon are used as target and carrier gas, respectively, during BCN synthesis. The obtained BCN films are annealed at different temperatures under vacuum condition. The effect of annealing temperature on the structure, mechanical properties and scratch behavior of the BCN films has been investigated. The results indicate that no decomposition products are found even the BCN films are annealed at 1000 °C. The hardness and elastic modulus of the films decrease with the increase of annealing temperatures. The BCN film annealed at 600 °C has the strongest scratch resistance. The friction coefficient of all BCN films is in range of 0.05 to 0.15.

Effect of annealing on the mechanical and scratch properties of BCN films obtained by magnetron sputtering deposition

International Nuclear Information System (INIS)

Xu, Shuyan; Ma, Xinxin; Wen, Huiying; Tang, Guangze; Li, Chunwei

2014-01-01

Highlights: • The amorphous BCN films were annealed at different temperatures under vacuum condition. • The order degree increases with the annealing temperature increasing, and the films do not decompose even the annealing temperature rise to 1000 °C. • The nano-hardness and modulus of the films decrease with the increasing of annealing temperatures. • The critical load of BCN films is not affected by the annealing temperature, and the films have good interfacial adhesion. • The scratch resistance properties of BCN film are improved by annealing at 600 °C. - Abstract: Boron-carbon-nitride (BCN) films have been fabricated by direct current unbalanced magnetron sputtering. Boron carbide/graphite compound and a mixture of nitrogen and argon are used as target and carrier gas, respectively, during BCN synthesis. The obtained BCN films are annealed at different temperatures under vacuum condition. The effect of annealing temperature on the structure, mechanical properties and scratch behavior of the BCN films has been investigated. The results indicate that no decomposition products are found even the BCN films are annealed at 1000 °C. The hardness and elastic modulus of the films decrease with the increase of annealing temperatures. The BCN film annealed at 600 °C has the strongest scratch resistance. The friction coefficient of all BCN films is in range of 0.05 to 0.15

Design of a magnetron injection gun for a 17.5-GHz

International Nuclear Information System (INIS)

Ha, H. J.; Kim, J. E.; Park, G. S.

1996-01-01

A gyrotwystron which is composed of cavities (gyro-klystron) and waveguides (gyro-TWT) is under investigation for broader bandwidth with high efficiency. A magnetron injection gun (MIG) for the gyrotwystron is designed with the trade-off equation for the MIG and optimized by computer simulation using the e-gun code. A 300-kW, 60-kV MIG with α ≡ υ t /υ z = 1.2 and Δυ z ≤ 5% designed for a 17.5-GHz gyrotwystron is discussed in this paper. Also, the effect of various MIG parameters, such as the beam voltage, the beam current, the magnetic field, the cathode radius and angle, and the MIG dimensions, on the characteristics of the beam (α, Δυ z ) is studied. (author)

Inverse Magnus force in free molecular flow

Science.gov (United States)

Herczynski, A.; Weidman, P.

2003-11-01

The sidewise force on a spinning sphere translating in a rarified gas is calculated assuming that the flow can be treated as a stream of free molecules. This approach was first introduced by Newton in his investigation of the drag force. While it is not fruitful at subsonic flows in normal conditions, it gives remarkably accurate results at hypersonic speeds. Here it is applied to the high Knudsen number flow over spinning spheres, cylinders, cubes and more generally any spinning parallelepiped. In all cases, the force is in the opposite direction to that of the classical Magnus effect in continuum flow. The simple calculation for a sphere reproduces the isothermal result obtained recently by Borg, et al. (Phys. Fluids, 15, 2003) using Maxwellian distribution functions. For any parallelepiped, including the cube, just like for the sphere and the cylinder, the force is shown to be steady. In each of these, the magnitude of the inverse Magnus force is proprtional to the product of the angular speed, translational speed, and the mas of the gas displaced by the object.

Monte Carlo simulation of ionization in a magnetron plasma

International Nuclear Information System (INIS)

Miranda, J.E.; Goeckner, M.J.; Goree, J.; Sheridan, T.E.

1990-01-01

A Monte Carlo simulation of electrons emitted from the cathode of a planar magnetron is tested against experiments that were reported by Wendt, Lieberman, and Meuth [J. Vac. Sci. Technol. A 6, 1827 (1988)] and by Gu and Lieberman [J. Vac. Sci. Technol. A 6, 2960 (1988)]. Comparing their measurements of the radial profile of current and the axial profile of optical emission to the ionization profiles predicted by the model, we find good agreement for a typical magnetic field strength of 456 G. We also find that at 456 G the product of the average number of ionizations left-angle N i right-angle and the secondary electron emission coefficient γ is ∼1. This indicates that secondary emission contributes significantly to the ionization that sustains the discharge. At 171 G, however, left-angle N i right-angle γ much-lt 1, revealing that cathode emission is inadequate to sustain a discharge at a low magnetic field

Characterisation of magnetron sputtered SmCo5 thin films

International Nuclear Information System (INIS)

Wang, Y.; Sood, D.K.; Kothari

1999-01-01

SmCo 5 thin films were deposited using DC magnetron sputtering on single crystal silicon substrate with chromium and SiO 2 top layers. Deposition was carried out at three different substrate temperatures: room temperature, 400 deg C and 600 deg C. Films were characterised by using Rutherford Backscattering Spectroscopy (RBS), X-ray Diffraction (XRD), Secondary Ion Mass Spectrometry (SIMS) and SQUID magnetometer. RBS analysis indicated that the films have excellent stoichiometry with the Sm to Co ratio of 1:5. This analysis also showed that the films deposited or annealed at high temperatures (≥600 deg C) indicated significant inter-diffusion at the interface between the barrier layer and the film. Oxygen was found to be the major impurity in the films. XRD data indicated that the films formed 1:5 and 2:17 phases under different deposition conditions. The preliminary studies of these films using magnetic force microscopy revealed the presence of magnetic domains

Optical emission and mass spectroscopy of plasma processes in reactive DC pulsed magnetron sputtering of aluminium oxide

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Pokorný, Petr; Bočan, Jiří; Fitl, Přemysl; Lančok, Ján; Musil, Jindřich

2010-01-01

Roč. 12, č. 3 (2010), 697-700 ISSN 1454-4164 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : reactive magnetron sputtering * alumina * plasma spectroscopy * mass spectroscopy * optical emission spectroscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

Time-reversal and Bayesian inversion

Science.gov (United States)

Debski, Wojciech

2017-04-01

Probabilistic inversion technique is superior to the classical optimization-based approach in all but one aspects. It requires quite exhaustive computations which prohibit its use in huge size inverse problems like global seismic tomography or waveform inversion to name a few. The advantages of the approach are, however, so appealing that there is an ongoing continuous afford to make the large inverse task as mentioned above manageable with the probabilistic inverse approach. One of the perspective possibility to achieve this goal relays on exploring the internal symmetry of the seismological modeling problems in hand - a time reversal and reciprocity invariance. This two basic properties of the elastic wave equation when incorporating into the probabilistic inversion schemata open a new horizons for Bayesian inversion. In this presentation we discuss the time reversal symmetry property, its mathematical aspects and propose how to combine it with the probabilistic inverse theory into a compact, fast inversion algorithm. We illustrate the proposed idea with the newly developed location algorithm TRMLOC and discuss its efficiency when applied to mining induced seismic data.

Influence of substrate temperature on the optical and electrical properties magnetron sputtering ITO films

International Nuclear Information System (INIS)

Khripunov, G.S.; Yurchenko, G.V.

1999-01-01

Electrical and optical properties of ITO films obtained at substrate temperature from 200 degree C to 500 degree C by magnetron sputtering of target 95% In 2 O 3 - 5% SnO 2 were studied. It was shown that the ITO film obtained at the substrate temperature 300 i N have optimum combination of the optical and electrical characteristics: resistivity 2.1 centre dot 10 -4 Ω cm, transmittance in visible spectral range about 88% at the thickness film 0.61 μ, factor of quality reaches 8.2 centre dot 10 -2 Ω 1

Post-deposition annealing effects in RF reactive magnetron sputtered indium tin oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Martinez, M A; Herrero, J; Gutierrez, M T [Inst. de Energias Renovables (CIEMAT), Madrid (Spain)

1992-05-01

Indium tin oxide films have been grown by RF reactive magnetron sputtering. The influence of the deposition parameters on the properties of the films has been investigated and optimized, obtaining a value for the figure of merit of 6700 ({Omega} cm){sup -1}. As-grown indium tin oxide films were annealed in vacuum and O{sub 2} atmosphere. After these heat treatments the electro-optical properties were improved, with values for the resistivity of 1.9x10{sup -4} {Omega} cm and the figure of merit of 26700 ({Omega} cm){sup -1}. (orig.).

Direct current magnetron sputtering deposition of InN thin films

International Nuclear Information System (INIS)

Cai Xingmin; Hao Yanqing; Zhang Dongping; Fan Ping

2009-01-01

In this paper, InN thin films were deposited on Si (1 0 0) and K9 glass by reactive direct current magnetron sputtering. The target was In metal with the purity of 99.999% and the gases were Ar (99.999%) and N 2 (99.999%). The properties of InN thin films were studied. Scanning electron microscopy (SEM) shows that the film surface is very rough and energy dispersive X-ray spectroscopy (EDX) shows that the film contains In, N and very little O. X-ray diffraction (XRD) and Raman scattering reveal that the film mainly contains hexagonal InN. The four-probe measurement shows that InN film is conductive. The transmission measurement demonstrates that the transmission of InN deposited on K9 glass is as low as 0.5% from 400 nm to 800 nm.

Spatially resolved electron density and electron energy distribution function in Ar magnetron plasmas used for sputter-deposition of ZnO-based thin films

Energy Technology Data Exchange (ETDEWEB)

Maaloul, L.; Gangwar, R. K.; Morel, S.; Stafford, L., E-mail: luc.stafford@umontreal.ca [Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7 (Canada)

2015-11-15

Langmuir probe and trace rare gases optical emission spectroscopy were used to analyze the spatial structure of the electron density and electron energy distribution function (EEDF) in a cylindrical Ar magnetron plasma reactor used for sputter-deposition of ZnO-based thin films. While a typical Bessel (zero order) diffusion profile was observed along the radial direction for the number density of charged particles at 21 cm from the ZnO target, a significant rise of these populations with respect to the Bessel function was seen in the center of the reactor at 4 cm from the magnetron surface. As for the EEDF, it was found to transform from a more or less Maxwellian far from the target to a two-temperature Maxwellian with a depletion of high-energy electrons where magnetic field confinement effects become important. No significant change in the behavior of the electron density and EEDF across a wide range of pressures (5–100 mTorr) and self-bias voltages (115–300 V) was observed during magnetron sputtering of Zn, ZnO, and In{sub 2}O{sub 3} targets. This indicates that sputtering of Zn, In, and O atoms do not play a very significant role on the electron particle balance and electron heating dynamics, at least over the range of experimental conditions investigated.

Bayesian inversion of seismic and electromagnetic data for marine gas reservoir characterization using multi-chain Markov chain Monte Carlo sampling

Energy Technology Data Exchange (ETDEWEB)

Ren, Huiying; Ray, Jaideep; Hou, Zhangshuan; Huang, Maoyi; Bao, Jie; Swiler, Laura

2017-12-01

In this study we developed an efficient Bayesian inversion framework for interpreting marine seismic amplitude versus angle (AVA) and controlled source electromagnetic (CSEM) data for marine reservoir characterization. The framework uses a multi-chain Markov-chain Monte Carlo (MCMC) sampler, which is a hybrid of DiffeRential Evolution Adaptive Metropolis (DREAM) and Adaptive Metropolis (AM) samplers. The inversion framework is tested by estimating reservoir-fluid saturations and porosity based on marine seismic and CSEM data. The multi-chain MCMC is scalable in terms of the number of chains, and is useful for computationally demanding Bayesian model calibration in scientific and engineering problems. As a demonstration, the approach is used to efficiently and accurately estimate the porosity and saturations in a representative layered synthetic reservoir. The results indicate that the seismic AVA and CSEM joint inversion provides better estimation of reservoir saturations than the seismic AVA-only inversion, especially for the parameters in deep layers. The performance of the inversion approach for various levels of noise in observational data was evaluated – reasonable estimates can be obtained with noise levels up to 25%. Sampling efficiency due to the use of multiple chains was also checked and was found to have almost linear scalability.

Bayesian inversion of seismic and electromagnetic data for marine gas reservoir characterization using multi-chain Markov chain Monte Carlo sampling

International Nuclear Information System (INIS)

Ren, Huiying; Ray, Jaideep; Hou, Zhangshuan; Huang, Maoyi; Bao, Jie; Swiler, Laura

2017-01-01

In this paper we developed an efficient Bayesian inversion framework for interpreting marine seismic Amplitude Versus Angle and Controlled-Source Electromagnetic data for marine reservoir characterization. The framework uses a multi-chain Markov-chain Monte Carlo sampler, which is a hybrid of DiffeRential Evolution Adaptive Metropolis and Adaptive Metropolis samplers. The inversion framework is tested by estimating reservoir-fluid saturations and porosity based on marine seismic and Controlled-Source Electromagnetic data. The multi-chain Markov-chain Monte Carlo is scalable in terms of the number of chains, and is useful for computationally demanding Bayesian model calibration in scientific and engineering problems. As a demonstration, the approach is used to efficiently and accurately estimate the porosity and saturations in a representative layered synthetic reservoir. The results indicate that the seismic Amplitude Versus Angle and Controlled-Source Electromagnetic joint inversion provides better estimation of reservoir saturations than the seismic Amplitude Versus Angle only inversion, especially for the parameters in deep layers. The performance of the inversion approach for various levels of noise in observational data was evaluated — reasonable estimates can be obtained with noise levels up to 25%. Sampling efficiency due to the use of multiple chains was also checked and was found to have almost linear scalability.

Bayesian inversion of seismic and electromagnetic data for marine gas reservoir characterization using multi-chain Markov chain Monte Carlo sampling

Science.gov (United States)

Ren, Huiying; Ray, Jaideep; Hou, Zhangshuan; Huang, Maoyi; Bao, Jie; Swiler, Laura

2017-12-01

In this study we developed an efficient Bayesian inversion framework for interpreting marine seismic Amplitude Versus Angle and Controlled-Source Electromagnetic data for marine reservoir characterization. The framework uses a multi-chain Markov-chain Monte Carlo sampler, which is a hybrid of DiffeRential Evolution Adaptive Metropolis and Adaptive Metropolis samplers. The inversion framework is tested by estimating reservoir-fluid saturations and porosity based on marine seismic and Controlled-Source Electromagnetic data. The multi-chain Markov-chain Monte Carlo is scalable in terms of the number of chains, and is useful for computationally demanding Bayesian model calibration in scientific and engineering problems. As a demonstration, the approach is used to efficiently and accurately estimate the porosity and saturations in a representative layered synthetic reservoir. The results indicate that the seismic Amplitude Versus Angle and Controlled-Source Electromagnetic joint inversion provides better estimation of reservoir saturations than the seismic Amplitude Versus Angle only inversion, especially for the parameters in deep layers. The performance of the inversion approach for various levels of noise in observational data was evaluated - reasonable estimates can be obtained with noise levels up to 25%. Sampling efficiency due to the use of multiple chains was also checked and was found to have almost linear scalability.

Synthesis of Ag-Cu-Pd alloy thin films by DC-magnetron sputtering: Case study on microstructures and optical properties

Science.gov (United States)

Rezaee, Sahar; Ghobadi, Nader

2018-06-01

The present study aims to investigate optical properties of Ag-Cu-Pd alloy thin films synthesized by DC-magnetron sputtering method. The thin films are deposited on the glass and silicon substrates using Argon gas and Ag-Cu-Pd target. XRD analysis confirms the successful growth of Ag, Cu, and Pd NPs with FCC crystalline structure. Moreover, UV-visible absorption spectroscopy is applied to determine optical properties of the prepared samples which are affected by changes in surface morphology. The existence of single surface plasmon resonance (SPR) peak near 350 nm proves the formation of silver nanoparticles with a slight red shift through increasing deposition time. Ineffective thickness method (ITM) and Derivation of ineffective thickness method (DITM) are applied to extract optical band gap and transition type via absorption spectrum. SEM and AFM analyses show the distribution of near-spherical nanoparticles covering the surface of thin films. Furthermore, thickness variation affects the grain size. In addition, TEM image reveals the uniform size distribution of nanoparticles with an average particle size of about 15 nm. The findings show that increasing grain size and crystallite order along with the decrease of structural defect and disorders decrease optical band gap from 3.86 eV to 2.58 eV.

Delineation, Characterization and Assessment of Gas-hydrates: Examples from Indian Offshore

Science.gov (United States)

Sain, K.

2017-12-01

Successful test productions in McKenzie delta, Alaska, Nankai Trough and more recently in South China Sea have provided great hopes for production of gas-hydrates in near future, and boosted national programs of many countries including India. It has been imperative to map the prospective zones of gas-hydrates and evaluate their resource potential. Hence, we have adopted a systematic strategy for the delineation, characterization and quantification of gas-hydrates based on seismic traveltime tomography, full-waveform inversion, impedance inversion, attributes computation and rock-physical modeling. The bathymetry, seafloor temperature, total organic carbon content, sediment-thickness, rate of sedimentation, geothermal gradient imply that shallow sediments of Indian deep water are good hosts for occurrences of gas-hydrates. From the analysis of multi-channel seismic (MCS) data, we have identified the Krishna-Godavari (KG), Mahanadi and Andaman basins as prospective for gas-hydrates, and their presence has been validated by drilling and coring of Indian Expeditions-01 and -02. The MCS data also shows BSR-like features in the Cauvery, Kerala-Konkan and Saurashtra basins indicating that gas-hydrates cannot be ruled out from these basins also. We shall present several approaches that have been applied to field seismic and well-log data for the detection, characterization and quantification of gas-hydrates along the Indian margin.

Joint inversion of geophysical and hydrological data for improved subsurface characterization

International Nuclear Information System (INIS)

Kowalsky, Michael B.; Chen, Jinsong; Hubbard, Susan S.

2006-01-01

Understanding fluid distribution and movement in the subsurface is critical for a variety of subsurface applications, such as remediation of environmental contaminants, sequestration of nuclear waste and CO2, intrusion of saline water into fresh water aquifers, and the production of oil and gas. It is well recognized that characterizing the properties that control fluids in the subsurface with the accuracy and spatial coverage needed to parameterize flow and transport models is challenging using conventional borehole data alone. Integration of conventional borehole data with more spatially extensive geophysical data (obtained from the surface, between boreholes, and from surface to boreholes) shows promise for providing quantitative information about subsurface properties and processes. Typically, estimation of subsurface properties involves a two-step procedure in which geophysical data are first inverted and then integrated with direct measurements and petrophysical relationship information to estimate hydrological parameters. However, errors inherent to geophysical data acquisition and inversion approaches and errors associated with petrophysical relationships can decrease the value of geophysical data in the estimation procedure. In this paper, we illustrate using two examples how joint inversion approaches, or simultaneous inversion of geophysical and hydrological data, offer great potential for overcoming some of these limitations

Gravity inversion code

International Nuclear Information System (INIS)

Burkhard, N.R.

1979-01-01

The gravity inversion code applies stabilized linear inverse theory to determine the topography of a subsurface density anomaly from Bouguer gravity data. The gravity inversion program consists of four source codes: SEARCH, TREND, INVERT, and AVERAGE. TREND and INVERT are used iteratively to converge on a solution. SEARCH forms the input gravity data files for Nevada Test Site data. AVERAGE performs a covariance analysis on the solution. This document describes the necessary input files and the proper operation of the code. 2 figures, 2 tables