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Sample records for characterizing magnetic materials

  1. SYNTHESIS AND CHARACTERIZATION OF ADVANCED MAGNETIC MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Monica Sorescu

    2004-09-22

    The work described in this grant report was focused mainly on the properties of novel magnetic intermetallics. In the first project, we synthesized several 2:17 intermetallic compounds, namely Nd{sub 2}Fe{sub 15}Si{sub 2}, Nd{sub 2}Fe{sub 15}Al{sub 2}, Nd{sub 2}Fe{sub 15}SiAl and Nd{sub 2}Fe{sub 15}SiMn, as well as several 1:12 intermetallic compounds, such as NdFe{sub 10}Si{sub 2}, NdFe{sub 10}Al{sub 2}, NdFe{sub 10}SiAl and NdFe{sub 10}MnAl. In the second project, seven compositions of Nd{sub x}Fe{sub 100-x-y}B{sub y} ribbons were prepared by a melt spinning method with Nd and B content increasing from 7.3 and 3.6 to 11 and 6, respectively. The alloys were annealed under optimized conditions to obtain a composite material consisting of the hard magnetic Nd{sub 2}Fe{sub 14}B and soft magnetic {alpha}-Fe phases, typical of a spring magnet structure. In the third project, intermetallic compounds of the type Zr{sub 1}Cr{sub 1}Fe{sub 1}T{sub 0.8} with T = Al, Co and Fe were subjected to hydrogenation. In the fourth project, we performed three crucial experiments. In the first experiment, we subjected a mixture of Fe{sub 3}O{sub 4} and Fe (80-20 wt %) to mechanochemical activation by high-energy ball milling, for time periods ranging from 0.5 to 14 hours. In the second experiment, we ball-milled Fe{sub 3}O{sub 4}:Co{sup 2+} (x = 0.1) for time intervals between 2.5 and 17.5 hours. Finally, we exposed a mixture of Fe{sub 3}O{sub 4} and Co (80-20 wt %) to mechanochemical activation for time periods ranging from 0.5 to 10 hours. In all cases, the structural and magnetic properties of the systems involved were elucidated by X-ray diffraction (XRD), Moessbauer spectroscopy and hysteresis loop measurements. The four projects resulted in four papers, which were published in Intermetallics, IEEE Transactions on Magnetics, Journal of Materials Science Letters and Materials Chemistry and Physics. The contributions reveal for the first time in literature the effect of

  2. The Characterization of the Magnetic Properties of Soft Magnetic Materials

    DEFF Research Database (Denmark)

    Larsen, Raino Michael

    1996-01-01

    The hysteresis curve and magnetic properties such as permeability, saturation induction, residual induction, coercive force and hysteresis losses are presented. The design and construction of equipment making it possible to measure true DC-values as well as AC-properties of toroid rings and...

  3. Synthesis and characterization of low-dimensional molecular magnetic materials

    Science.gov (United States)

    Liu, Chen

    This dissertation presents experimental results from the synthesis and structural, magnetic characterization of representative low-dimensional molecule-based magnetic materials. Most of the materials reported in this dissertation, both coordination polymers and cuprate, are obtained as the result of synthesizing and characterizing spin ladder systems; except the material studied in Chapter 2, ferricenyl(III)trisferrocenyl(II)borate, which is not related to the spin ladder project. The interest in spin ladder systems is due to the discovery of high-temperature superconductivity in doped cuprates possessing ladder-like structures, and it is hoped that investigation of the magnetic behavior of ladder-like structures will help us understand the mechanism of high-temperature superconductivity. Chapter 1 reviews fundamental knowledge of molecular magnetism, general synthetic strategies for low-dimensional coordination polymers, and a brief introduction to the current status of research on spin ladder systems. Chapter 2 presents a modified synthetic procedure of a previously known monomeric complex, ferricenyl(III)trisferrocenyl(II)borate, 1. Its magnetic properties were characterized and previous results have been disproved. Chapter 3 investigates the magnetism of [CuCl2(CH3CN)] 2, 2, a cuprate whose structure consists of isolated noninterpenetrating ladders formed by the stacking of Cu(II) dimers. This material presents an unexpected ferromagnetic interaction both within the dimeric units and between the dimers, and this behavior has been rationalized based on the effect of its terminal nonbridging ligands. In Chapter 4, the synthesis and magnetism of two ladder-like coordination polymers, [Co(NO3)2(4,4'-bipyridine) 1.5(MeCN)]n, 3, and Ni2(2,6-pyridinedicarboxylic acid)2(H2O)4(pyrazine), 4, are reported. Compound 3 possesses a covalent one-dimensional ladder structure in which Co(II) ions are bridged through bipyridine molecules. Compared to the materials discussed in

  4. Eddy current characterization of magnetic treatment of materials

    Science.gov (United States)

    Chern, E. James

    1992-01-01

    Eddy current impedance measuring methods have been applied to study the effect that magnetically treated materials have on service life extension. Eddy current impedance measurements have been performed on Nickel 200 specimens that have been subjected to many mechanical and magnetic engineering processes: annealing, applied strain, magnetic field, shot peening, and magnetic field after peening. Experimental results have demonstrated a functional relationship between coil impedance, resistance and reactance, and specimens subjected to various engineering processes. It has shown that magnetic treatment does induce changes in a material's electromagnetic properties and does exhibit evidence of stress relief. However, further fundamental studies are necessary for a thorough understanding of the exact mechanism of the magnetic-field processing effect on machine tool service life.

  5. Preparation and characterization of multifunctional magnetic mesoporous calcium silicate materials

    International Nuclear Information System (INIS)

    We have prepared multifunctional magnetic mesoporous Fe–CaSiO3 materials using triblock copolymer (P123) as a structure-directing agent. The effects of Fe substitution on the mesoporous structure, in vitro bioactivity, magnetic heating ability and drug delivery property of mesoporous CaSiO3 materials were investigated. Mesoporous Fe–CaSiO3 materials had similar mesoporous channels (5–6 nm) with different Fe substitution. When 5 and 10% Fe were substituted for Ca in mesoporous CaSiO3 materials, mesoporous Fe–CaSiO3 materials still showed good apatite-formation ability and had no cytotoxic effect on osteoblast-like MC3T3-E1 cells evaluated by the elution cell culture assay. On the other hand, mesoporous Fe–CaSiO3 materials could generate heat to raise the temperature of the surrounding environment in an alternating magnetic field due to their superparamagnetic property. When we use gentamicin (GS) as a model drug, mesoporous Fe–CaSiO3 materials release GS in a sustained manner. Therefore, magnetic mesoporous Fe–CaSiO3 materials would be a promising multifunctional platform with bone regeneration, local drug delivery and magnetic hyperthermia. (paper)

  6. Microstructure characterization and magnetic properties of nano structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.C

    2000-07-01

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe{sub 78}Si{sub 9}B{sub 13} ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy [eds.]; selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  7. Microstructure characterization and magnetic properties of nano structured materials

    International Nuclear Information System (INIS)

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe78Si9B13 ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy (Eds.); selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  8. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    Science.gov (United States)

    Esa, Mohammad Faris Mohammad; Rahim, Faszly; Hassan, Ibrahim Haji; Hanifah, Sharina Abu

    2015-09-01

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  9. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    International Nuclear Information System (INIS)

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration

  10. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Esa, Mohammad Faris Mohammad; Hassan, Ibrahim Haji [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia); Rahim, Faszly; Hanifah, Sharina Abu [School of Environmental Scieces and Natural Resources Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

    2015-09-25

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  11. Magnetic characterization of ferrite materials used in the ELENA magnetic pick-ups

    CERN Document Server

    Favia, Giorgia; CERN. Geneva. ATS Department

    2015-01-01

    The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron designed for cooling and further decelerating the 5.3 MeV antiprotons delivered by the CERN Antiproton Decelerator (AD). The ring is equipped with two magnetic pick-ups used for longitudinal beam diagnostics. These ultra low noise AC beam transformers consist of a doubly shielded, ferrite-loaded cavity with a ceramic gap in the beam pipe, a secondary winding to which an ultralow noise JFET head amplifier with feedback is connected. The JFET head amplifier is mounted close to the cavity and the AC beam transformers are covering respectively the 0.003-3MHz frequency range (low frequency type) and 0.8-30 MHz frequency range (high frequency type) [1]. The ferrite material used to couple primary and secondary in the beam transformer, has a key impact in the noise characteristics of the amplifier. For this reason a magnetic characterization of the selected ferrite rings has been carried out and is reported in the following.

  12. Frequency characterization of thin soft magnetic material layers used in spiral inductors

    International Nuclear Information System (INIS)

    The paper details the characterization of thin magnetic materials layers, particularly soft materials, with respect to their behaviour in frequency (from 10 MHz to 1 GHz). The proposed method is suitable for any soft but insulating magnetic material; Yttrium Iron Garnet (YIG) is used as an example. The principle is based on a comparison between simulations for different values of the permeability and measurement values versus frequency of planar inductor structures; an experimental validation is proposed as well. Thin magnetic material is first deposited on an alumina substrate using RF sputtering technique; a planar spiral winding of copper is then deposited on the magnetic material by the same technique. The effective permeability versus frequency is obtained by comparing two samples of spiral windings with and without magnetic material. Network analyser measurements on samples of various geometrical dimensions and of different thicknesses are necessary to determine the effective magnetic permeability; we have obtained a relative effective permeability of about 30 for seven turns spiral inductor of a 17 μm YIG film. - Highlights: ► A simple and original method is presented for the characterization of soft magnetic layer. ► This is a non-destructive method based on standard equipment. ► The principle is based on a comparison between simulations and measurement. ► An experimental validation is proposed as well.

  13. Magnetic characterization of creep-fatigue damage for energy structural materials

    International Nuclear Information System (INIS)

    Magnetic characterization of creep-fatigue damage for welded specimens of austenitic stainless steel (SUS316FR) and high-chromium steel (Mod.9Cr-1Mo) steel was performed using magnetic force microscope and Hall sensor. In SUS316FR volume fraction of δ-ferrite at weld metal region decreased by creep or creep-fatigue and the remanent magnetic flux density at weld metal region also decreased. In Mod.9Cr-1Mo steel magnetic characteristics at weld metal region were different from those at base metal initially, however, during creep or creep fatigue the difference of magnetic characteristics between welded metal and base metal became small. It was found that the degradation mechanism for these energy structural materials during creep or creep fatigue could be clarified by magnetic characterization techniques. (author)

  14. Handbook of Advanced Magnetic Materials

    CERN Document Server

    Liu, Yi; Shindo, Daisuke

    2006-01-01

    From high-capacity, inexpensive hard drives to mag-lev trains, recent achievements in magnetic materials research have made the dreams of a few decades ago reality. The objective of Handbook of Advanced Magnetic Materials is to provide a timely, comprehensive review of recent progress in magnetic materials research. This broad yet detailed reference consists of four volumes: 1.) Nanostructured advanced magnetic materials, 2.) Characterization and simulation of advanced magnetic materials, 3.) Processing of advanced magnetic materials, and 4.) Properties and applications of advanced magnetic materials The first volume documents and explains recent development of nanostructured magnetic materials, emphasizing size effects. The second volume provides a comprehensive review of both experimental methods and simulation techniques for the characterization of magnetic materials. The third volume comprehensively reviews recent developments in the processing and manufacturing of advanced magnetic materials. With the co...

  15. Materials engineering, characterization, and applications of the organicbased magnet, V[TCNE

    Science.gov (United States)

    Harberts, Megan

    Organic materials have advantageous properties such as low cost and mechanical flexibility that have made them attractive to complement traditional materials used in electronics and have led to commercial success, especially in organic light emitting diodes (OLEDs). Many rapidly advancing technologies incorporate magnetic materials, leading to the potential for creating analogous organic-based magnetic applications. The semiconducting ferrimagnet, vanadium tetracyanoethylene, V[TCNE]x˜2, exhibits room temperature magnetic ordering which makes it an attractive candidate. My research is focused on development of thin films of V[TCNE]x˜2 through advancement in growth, materials engineering, and applications. My thesis is broken up into two sections, the first which provides background and details of V[TCNE]x˜2 growth and characterization. The second section focuses on advances beyond V[TCNE]x˜2 film growth. The ordering of the chapters is for the ease of the reader, but encompasses work that I led and robust collaborations that I have participated in. V[TCNE]x˜2 films are deposited through a chemical vapor deposition process (CVD). My advancements to the growth process have led to higher quality films which have higher magnetic ordering temperatures, more magnetically homogenous samples, and extremely narrow ferromagnetic resonance (FMR) linewidths. Beyond improvements in film growth, materials engineering has created new materials and structures with properties to compliment thin film V[TCNE]x˜2. Though a robust collaboration with chemistry colleagues, modification of the molecule TCNE has led to the creation of new magnetic materials vanadium methyl tricyanoethylene carboxylate, V[MeTCEC]x and vanadium ethyl tricyanoethylene carboxylate, V[ETCEC]x. Additionally, I have lead a project to deposit V[TCNE]x˜2 on periodically patterned substrates leading to the formation of a 1-D array of V[TCNE]x˜2 nanowires. These arrays exhibit in-plane magnetic anisotropy

  16. Magnetism and magnetic materials

    CERN Document Server

    Coey, J M D

    2010-01-01

    Covering basic physical concepts, experimental methods, and applications, this book is an indispensable text on the fascinating science of magnetism, and an invaluable source of practical reference data. Accessible, authoritative, and assuming undergraduate familiarity with vectors, electromagnetism and quantum mechanics, this textbook is well suited to graduate courses. Emphasis is placed on practical calculations and numerical magnitudes - from nanoscale to astronomical scale - focussing on modern applications, including permanent magnet structures and spin electronic devices. Each self-contained chapter begins with a summary, and ends with exercises and further reading. The book is thoroughly illustrated with over 600 figures to help convey concepts and clearly explain ideas. Easily digestible tables and data sheets provide a wealth of useful information on magnetic properties. The 38 principal magnetic materials, and many more related compounds, are treated in detail

  17. Magnetism Materials and Applications

    CERN Document Server

    Trémolet de Lacheisserie, Étienne; Schlenker, Michel

    2005-01-01

    This book treats permanent magnet (hard) materials, magnetically soft materials for low-frequency applications and for high-frequency electronics, magnetostrictive materials, superconductors, magnetic-thin films and multilayers, and ferrofluids. Chapters are dedicated to magnetic recording, the role of magnetism in magnetic resonance imaging (MRI), and instrumentation for magnetic measurements.   

  18. Characterization of magnetic materials by low-field microwave absorption techniques

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, R. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico)], E-mail: monjaras@servidor.unam.mx; Alvarez, G. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico); Montiel, H. [Departamento de Tecnociencias, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Gutierrez, M.P. [Departamento de Quimica Inorganica y Nuclear, Facultad de Quimica, Universidad Nacional Autonoma de Mexico (Mexico); Mata-Zamora, M.E. [Departamento de Tecnociencias, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Barron, F.; Sanchez, A.Y.; Betancourt, I. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico); Zamorano, R. [Departamento de Ciencia de Materiales, Instituto Politecnico Nacional (Mexico)

    2008-07-15

    A low-field non-resonant microwave absorption has recently been observed in a variety of magnetically ordered materials at low DC fields (-1000 Oe {<=}H{sub DC}{<=}+1000 Oe), which is known as low-field microwave absorption (LFA). It has been shown that LFA is essentially similar to giant magnetoimpedance (GMI), and clearly different from ferromagnetic resonance (FMR). LFA strongly depends on the anisotropy field of the sample. In contrast with FMR (which can be described as the homogeneous precession of spins in the saturated state), LFA can be thought as a spin rotation process occurring during the magnetic saturation. In this work, we present a detailed study of the basic features of LFA in several types of materials: ferrites and amorphous microwires and ribbons; in particular the effects sample shape, temperature up to the Curie transition, the influence of easy axis and the effects of annealings. These examples show that once LFA is fully understood, it can become a powerful characterization tool.

  19. Characterizing the shape and material properties of hidden targets from magnetic induction data

    OpenAIRE

    Paul D Ledger, William R.B. Lionheart

    2015-01-01

    The aim of this paper is to show that, for the eddy current model, the leading order term for the perturbation in the magnetic field, due to the presence of a small conducting magnetic inclusion, can be expressed in terms of a symmetric rank 2 polarization tensor. This tensor contains information about the shape and material properties of the object and is independent of position. We apply a recently derived asymptotic formula for the perturbed magnetic field, due to the presence ...

  20. ATR-FTIR Spectroscopy for the Characterization of Magnetic Tape Materials

    Directory of Open Access Journals (Sweden)

    Tobias Weber

    2011-01-01

    Full Text Available The Music Archive of the Ethnological Museum (National Museums Berlin, Germany houses a large number of recordings on phonograph cylinders and magnetic tapes. The project ILKAR (Integrated Solutions for Preservation, Archiving and Conservation of Endangered Magnetic Tapes and Cylinders aims at prioritising the digitisation of the more than 10,000 magnetic tapes of the Archive. In this contribution, the usefulness of Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy for the characterisation of the constituent materials of magnetic tapes is discussed. The final aim of the research is the characterisation of the most endangered materials of the Archive's collection and the evaluation of their conservation state. A range of complementary techniques should aid in the characterisation of the main tape types housed in the archive and will help to achieve a better understanding of their decay processes.

  1. Bulk Combinatorial Synthesis and High Throughput Characterization for Rapid Assessment of Magnetic Materials: Application of Laser Engineered Net Shaping (LENS™)

    Science.gov (United States)

    Geng, J.; Nlebedim, I. C.; Besser, M. F.; Simsek, E.; Ott, R. T.

    2016-07-01

    A bulk combinatorial approach for synthesizing alloy libraries using laser engineered net shaping (LENS™; i.e., 3D printing) was utilized to rapidly assess material systems for magnetic applications. The LENS™ system feeds powders in different ratios into a melt pool created by a laser to synthesize samples with bulk (millimeters) dimensions. By analyzing these libraries with autosampler differential scanning calorimeter/thermal gravimetric analysis and vibrating sample magnetometry, we are able to rapidly characterize the thermodynamic and magnetic properties of the libraries. The Fe-Co binary alloy was used as a model system and the results were compared with data in the literature.

  2. Bulk Combinatorial Synthesis and High Throughput Characterization for Rapid Assessment of Magnetic Materials: Application of Laser Engineered Net Shaping (LENS™)

    Science.gov (United States)

    Geng, J.; Nlebedim, I. C.; Besser, M. F.; Simsek, E.; Ott, R. T.

    2016-04-01

    A bulk combinatorial approach for synthesizing alloy libraries using laser engineered net shaping (LENS™; i.e., 3D printing) was utilized to rapidly assess material systems for magnetic applications. The LENS™ system feeds powders in different ratios into a melt pool created by a laser to synthesize samples with bulk (millimeters) dimensions. By analyzing these libraries with autosampler differential scanning calorimeter/thermal gravimetric analysis and vibrating sample magnetometry, we are able to rapidly characterize the thermodynamic and magnetic properties of the libraries. The Fe-Co binary alloy was used as a model system and the results were compared with data in the literature.

  3. Materials Characterization of Feraheme/Ferumoxytol and Preliminary Evaluation of Its Potential for Magnetic Fluid Hyperthermia

    Directory of Open Access Journals (Sweden)

    Jon Dobson

    2013-08-01

    Full Text Available Feraheme, is a recently FDA-cleared superparamagnetic iron oxide nanoparticle (SPION-based MRI contrast agent that is also employed in the treatment of iron deficiency anemia. Feraheme nanoparticles have a hydrodynamic diameter of 30 nm and consist of iron oxide crystallites complexed with a low molecular weight, semi-synthetic carbohydrate. These features are attractive for other potential biomedical applications such as magnetic fluid hyperthermia (MFH, since the carboxylated polymer coating affords functionalization of the particle surface and the size allows for accumulation in highly vascularized tumors via the enhanced permeability and retention effect. This work presents morphological and magnetic characterization of Feraheme by transmission electron microscopy (TEM, Energy dispersive X-ray spectroscopy (EDX, and superconducting quantum interference device (SQUID magnetometry. Additionally, the results of an initial evaluation of the suitability of Feraheme for MFH applications are described, and the data indicate the particles possess promising properties for this application.

  4. Magnetic Materials in sustainable energy

    Science.gov (United States)

    Gutfleisch, Oliver

    2012-02-01

    A new energy paradigm, consisting of greater reliance on renewable energy sources and increased concern for energy efficiency in the total energy lifecycle, has accelerated research in energy-related technologies. Due to their ubiquity, magnetic materials play an important role in improving the efficiency and performance of devices in electric power generation, conversion and transportation. Magnetic materials are essential components of energy applications (i.e. motors, generators, transformers, actuators, etc.) and improvements in magnetic materials will have significant impact in this area, on par with many ``hot'' energy materials efforts. The talk focuses on the state-of-the-art hard and soft magnets and magnetocaloric materials with an emphasis on their optimization for energy applications. Specifically, the impact of hard magnets on electric motor and transportation technologies, of soft magnetic materials on electricity generation and conversion technologies, and of magnetocaloric materials for refrigeration technologies, will be discussed. The synthesis, characterization, and property evaluation of the materials, with an emphasis on structure-property relationships, will be examined in the context of their respective markets as well as their potential impact on energy efficiency. Finally, considering future bottle-necks in raw materials and in the supply chain, options for recycling of rare-earth metals will be analyzed.ootnotetextO. Gutfleisch, J.P. Liu, M. Willard, E. Bruck, C. Chen, S.G. Shankar, Magnetic Materials and Devices for the 21st Century: Stronger, Lighter, and More Energy Efficient (review), Adv. Mat. 23 (2011) 821-842.

  5. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  6. Frontiers in Magnetic Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Magnetic Materials focuses on the current achievements and state-of-the-art advancements in magnetic materials. Several lines of development- High-Tc Superconductivity, Nanotechnology and refined experimental techniques among them – raised knowledge and interest in magnetic materials remarkably. The book comprises 24 chapters on the most relevant topics written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students.

  7. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology

    International Nuclear Information System (INIS)

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H2O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  8. Magnetic refrigeration materials

    Institute of Scientific and Technical Information of China (English)

    戴闻; 沈保根; 高政祥

    2001-01-01

    Magnetic refrigeration has drawn much attention because of its greater efficiency and higher reliability than the traditional gas-cycle refrigeration technology. Recently, a kind of new materials with a giant magnetocaloric effect in the subroom temperature range, Gd5 (Six Ge1- x)4, was discovered, which boosts the search for high-performance magnetic refrigerants. However, the intermetallic compounds Gd5 (SixGe1 - x )4 belong to the first order transition materials; their performance in practical magnetic refrigeration cycles remains controversial. In this paper the developing tendency of the refrigerants are discussed on the basis of our work.

  9. Practical materials characterization

    CERN Document Server

    2014-01-01

    Presents cross-comparison between materials characterization techniquesIncludes clear specifications of strengths and limitations of each technique for specific materials characterization problemFocuses on applications and clear data interpretation without extensive mathematics

  10. Synthesis and Characterization of Novel Magnetic Nano-Materials and Studying Their Potential Application in Recovery of Metal Ions

    International Nuclear Information System (INIS)

    The release of hazardous pollutants and their dispersion in the environment can cause adverse impacts on both environment and public health. These pollutants are more easily controlled when they are generated than after they are dispersed. Therefore, it is necessity of prime to design treatment processes can remove the contaminants at their source. Recently, many industrial and nuclear activities produce large amounts of wastewaters that contains a variety of contaminants. These contaminants may include toxic metals or radioactive isotopes. The efforts in this work are firstly directed to prepare some materials to be used as sorbents for removal of Sr(II), Cd(II) and Eu(III) radionuclide from waste solutions. The study concerned with the characterization of the prepared sorbents using surface area (BET), FTIR, X-Ray, TG/DTA, SEM and magnetic properties to throw light on its sense when practically used as a decontaminating material in aqueous systems. Also, the work involves the sorption of Sr(II), Cd(II) and Eu(III) ions from aqueous solutions under different experimental conditions to clarify the affinity of these sorbents and to assess main factors affecting the sorption behavior of these species. This is to evaluate the efficiency of these sorbents to be used as decontaminating materials for treatment of hazard wastes and finally to judge the criteria of sorbents selectivity towards the studies solutes.

  11. Handbook of Magnetic Materials

    International Nuclear Information System (INIS)

    Magnetoelectronics is a novel and rapidly developing field. This new field is frequently referred to as spin-electronics or spintronics. It includes spin-utilizing devices that need neither a magnetic field nor magnetic materials. In semiconductor devices, the spin of the carriers has only played a very modest role so far because well established semiconductor devices are non-magnetic and show only negligible effects of spin. Nanoscale thin films and multilayers, nanocrystalline magnetic materials, granular films, and amorphous alloys have attracted much attention in the last few decades, in the field of basic research as well as in the broader field of materials science. Such heterogeneous materials display uncommon magnetic properties that virtually do no occur in bulk materials. This is true, in particular with respect to surface (interface) magnetic anisotropy and surface (interface) magnetostrictive strains and giant magnetoresistance. The local atomic arrangement at the interface differs strongly from that in the bulk. The local symmetry is lowered, so that some interactions are changed or are missing altogether. The interface atoms may envisaged as forming a new phase and some properties characteristic of this phase may become predominant for the entire system. This becomes particularly evident in the case of interfacial magnetostriction which can lead to a decrease (almost to zero) or to an increase(over the bulk value) of the resulting magnetostriction of the nanoscale system. There are various forms of the interplay of magnetism and superconductivity, which can be divided into competition and coexistence phenomena. For instance, a strong competition is found in high-Tc cuprates. In these materials, depending on the doping rate, either Neel-type antiferromagnetism moments (e.g. from 4f-elements) with superconductivity is known to occur in systems where the concentration of these moments is sufficiently small or where they are antiferromagnetically ordered

  12. Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Materials Characterization Facility enables detailed measurements of the properties of ceramics, polymers, glasses, and composites. It features instrumentation...

  13. Superconducting materials and magnets

    International Nuclear Information System (INIS)

    The Technical Committee Meeting on Superconducting Materials and Magnets was convened by the IAEA and held by invitation of the Japanese government on September 4-6, 1989 in Tokyo. The meeting was hosted by the National Research Institute for Metals. Topics of the conference related to superconducting magnets and technology with particular application to fusion and the superconducting supercollider. Technology using both high and low-temperature superconductors was discussed. This document is a compendium of the papers presented at the meeting. Refs, figs and tabs

  14. Skyrmions in magnetic materials

    CERN Document Server

    Seki, Shinichiro

    2016-01-01

    This brief reviews current research on magnetic skyrmions, with emphasis on formation mechanisms, observation techniques, and materials design strategies. The response of skyrmions, both static and dynamical, to various electromagnetic fields is also covered in detail. Recent progress in magnetic imaging techniques has enabled the observation of skyrmions in real space, as well as the analysis of their ordering manner and the details of their internal structure. In metallic systems, conduction electrons moving through the skyrmion spin texture gain a nontrivial quantum Berry phase, which provides topological force to the underlying spin texture and enables the current-induced manipulation of magnetic skyrmions. On the other hand, skyrmions in an insulator can induce electric polarization through relativistic spin-orbit interaction, paving the way for the control of skyrmions by an external electric field without loss of Joule heating. Because of its nanometric scale, particle nature, and electric controllabil...

  15. Nanostructured electronic and magnetic materials

    Indian Academy of Sciences (India)

    R V Ramanujan

    2003-02-01

    Research and development in nanostructured materials is one of the most intensely studied areas in science. As a result of concerted R & D efforts, nanostructured electronic and magnetic materials have achieved commercial success. Specific examples of novel industrially important nanostructured electronic and magnetic materials are provided. Advantages of nanocrystalline magnetic materials in the context of both materials and devices are discussed. Several high technology examples of the use of nanostructured magnetic materials are presented. Methods of processing nanostructured materials are described and the examples of sol gel, rapid solidification and powder injection moulding as potential processing methods for making nanostructured materials are outlined. Some opportunities and challenges are discussed.

  16. Nano structured Magnetic Materials

    International Nuclear Information System (INIS)

    The saga of nanostructured magnetic materials (NMMs) has prevailed since the discovery of the first giant magnetoresistance (GMR) effect in metals in 1988. NMMs represent a unique system that incorporates the interplay between the properties associated with spin degrees of freedom and the nanoscaled structures, which provide a very strong platform for exploring both basic science and technical applications in the fields of solid-state physics, chemistry, materials science, and engineering. In fact, an active research field called “spintronics,” which has a big overlap with NMMs, has emerged and prevailed very recently. Through manipulation of spin of electrons in solids, a wide variety of NMMs and devices have been playing a prominent role in information processing and transport in our modern life. A rich variety of materials, such as transition metals, manganite, wide bandgap semiconductors, and nanocomposites, have already been developed for generating well-controlled nanostructures with new functionalities. Many scientists believe that the 21st century will be a “Century of Spin.” Nanomaterials and nanotechnologies have provided historical opportunities for research and development of novel spintronics materials and devices. NMSs manifest fascinating properties compared to the bulks because of size effect and quantum effect. Nanotechnologies have been proven to be an effective way to fabricate devices with fine nanostructures. The combination of spintronics and nanomaterials will undisputedly open new pathways in solid-state physics. The present special issue focuses on the recent development in the understanding of the synthesis, the studies on magnetic properties of nanostructures, and their potential applications based on the multiple functionalities.

  17. Magnetism and metallurgy of soft magnetic materials

    CERN Document Server

    Chen, Chih-Wen

    2011-01-01

    Soft magnetic materials are economically and technologically the most important of all magnetic materials. In particular, the development of new materials and novel applications for the computer and telecommunications industries during the past few decades has immensely broadened the scope and altered the nature of soft magnetic materials. In addition to metallic substances, nonmetallic compounds and amorphous thin films are coming increasingly important. This thorough, well-organized volume - on of the most comprehensive treatments available - offers a coherent, logical presentation of the p

  18. Sol-gel hybrid materials for aerospace applications: Chemical characterization and comparative investigation of the magnetic properties

    Science.gov (United States)

    Catauro, Michelina; Mozzati, Maria Cristina; Bollino, Flavia

    2015-12-01

    In the material science field, weightless conditions can be successfully used to understand the relationship between manufacturing process, structure and properties of the obtained materials. Aerogels with controlled microstructure could be obtained by sol-gel methods in microgravity environment, simulated using magnetic levitation if they are diamagnetic. In the present work, a sol-gel route was used to synthesize class I, organic-inorganic nanocomposite materials. Two different formulations were prepared: the former consisted in a SiO2 matrix in which different percentages of polyethylene glycol (PEG) were incorporated, the latter was a ZrO2 matrix entrapping different amounts of poly (ε-caprolactone) (PCL). Fourier Transform Infrared Spectroscopy (FT-IR) detected that the organic and the inorganic components in both the formulation interact by means of hydrogen bonds. X-ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials and Scanning Electron Microscope (SEM) showed that they have homogeneous morphology and are nanocomposites. Superconducting Quantum Interference Device (SQUID) magnetometry confirmed the expected diamagnetic character of those hybrid systems. The obtained results were compared to those achieved in previous studies regarding the influence of the polymer amount on the magnetic properties of SiO2/PCL and ZiO2/PEG hybrids, in order to understand how the diamagnetic susceptibility is influenced by variation of both the inorganic matrix and organic component.

  19. Structural materials for fusion magnets

    International Nuclear Information System (INIS)

    Of major technical and cost impact to Magnetic Fusion Energy development are the materials for the magnet structure. Likened to gas pressure, the magnetic field lines try to expand the structure with equivalent pressures up to 1000 atm. Not only are large tensile forces produced, but significant bending forces may also be present. To withstand these forces in the restricted spaces available, materials of exceptional strength and toughness are required. In this regard, the low-temperature environment of superconducting magnets can be an advantage because many materials exhibit enhanced properties at reduced temperatures. Those materials and fabrication techniques that are attractive to fusion magnets are discussed and relative comparisons made. Considerations such as strength, toughness, and joining techniques are balanced agains recommended design criteria to reach an optimum design. Several examples of material selection are cited for large fusion magnets such as Baseball II, the Mirror Fusion Test Facility, the Toroidal Fusion Test Facility, and the Large Coil Project. (orig.)

  20. Structural materials for fusion magnets

    International Nuclear Information System (INIS)

    Of major technical and cost impact to Magnetic Fusion Energy development are the materials for the magnet structure. Those materials and fabrication techniques that are attractive to fusion magnets are discussed and relative comparisons made. Considerations such as strength, toughness, and joining techniques are balanced against recommended design criteria to reach an optimum design. Several examples of material selection are cited for large fusion magnets such as Base II, the Mirror Fusion Test Facility, the Toroidal Fusion Test Facility, and the Large Coil Project

  1. Secondary resonance magnetic force microscopy using an external magnetic field for characterization of magnetic thin films

    Science.gov (United States)

    Liu, Dongzi; Mo, Kangxin; Ding, Xidong; Zhao, Liangbing; Lin, Guocong; Zhang, Yueli; Chen, Dihu

    2015-09-01

    A bimodal magnetic force microscopy (MFM) that uses an external magnetic field for the detection and imaging of magnetic thin films is developed. By applying the external modulation magnetic field, the vibration of a cantilever probe is excited by its magnetic tip at its higher eigenmode. Using magnetic nanoparticle samples, the capacity of the technique which allows single-pass imaging of topography and magnetic forces is demonstrated. For the detection of magnetic properties of thin film materials, its signal-to-noise ratio and sensitivity are demonstrated to be superior to conventional MFM in lift mode. The secondary resonance MFM technique provides a promising tool for the characterization of nanoscale magnetic properties of various materials, especially of magnetic thin films with weak magnetism.

  2. Electronic, magnetic, and optical materials

    CERN Document Server

    Fulay, Pradeep

    2013-01-01

    Technological aspects of ferroelectric, piezoelectric and pyroelectric materials are discussed in detail, in a way that should allow the reader to select an optimal material for a particular application. The basics of magnetostatics are described clearly, as are a wide range of magnetic properties of materials … .-Tony Harker, Department of Physics and Astronomy, University College London

  3. Bragg diffraction from magnetic materials

    DEFF Research Database (Denmark)

    Lebech, B.

    2002-01-01

    Neutrons form a penetrating neutral probe, which makes it possible to use neutrons scattering techniques to study bulk materials, localise both light and heavy atoms and to distinguish between isotopes (e.g. hydrogen and deuterium). These properties make neutron scattering complementary to X......-ray scattering when studying crystalline properties of matter. In addition, neutrons possess magnetic moments of the same order of magnitude as the atomic magnetic moments in elements and this makes neutrons highly suited for studies of the order and interactions between the magnetic moments in magnetic...... materials. This will be illustrated by reviewing the ordered magnetic structures found in some simple elements and in some chemically more complex systems containing several magnetic elements. The different scattering techniques (two- and three-axis neutron scattering, small angle neutron scattering...

  4. Characterization of magnetic nanoparticles using programmed quadrupole magnetic field-flow fractionation

    OpenAIRE

    Williams, P. Stephen; Carpino, Francesca; Zborowski, Maciej

    2010-01-01

    Quadrupole magnetic field-flow fractionation is a relatively new technique for the separation and characterization of magnetic nanoparticles. Magnetic nanoparticles are often of composite nature having a magnetic component, which may be a very finely divided material, and a polymeric or other material coating that incorporates this magnetic material and stabilizes the particles in suspension. There may be other components such as antibodies on the surface for specific binding to biological ce...

  5. Magnetic Materials for Current Transformers

    CERN Document Server

    Aguilera, S; Ruffieux, P

    2013-01-01

    At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a vari...

  6. Magnetic spectroscopy and microscopy of functional materials

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Catherine Ann [Univ. of Mainz (Germany)

    2011-05-01

    Heusler intermetallics Mn2Y Ga and X2MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X2MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn2Y Ga to the logical Mn3Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co2FeSi (Appendix B).

  7. Preparation and characterization of immobilized lipase on magnetic hydrophobic microspheres

    DEFF Research Database (Denmark)

    Guo, Zheng; Bai, Shu; Sun, Yan

    2003-01-01

    A novel magnetic poly(vinyl acetate (VAc)–divinyl benzene (DVB)) material (8–34 μm) was synthesized by copolymerization of vinyl acetate and divinyl benzene using oleic acid-stabilized magnetic colloids as magnetic cores. The magnetic colloids and the copolymer microspheres were characterized with...

  8. Novel nano-structured materials: Preparation by self- assembly techniques and study of physical properties by x-ray analysis and magnetic characterization

    Science.gov (United States)

    Wiemann, Joan Ann K.

    2000-10-01

    The properties and characteristics of nano-structured materials can be quite different from the bulk form of the material. By forming nano-particles, electrical and magnetic properties may be tailored or enhanced beyond that of bulk materials. In this work several single and composite nano-phase materials were prepared by chemical or physical methods. Techniques used for characterization include magnetometry, Mössbauer analysis, x-ray diffractometry, x-ray reflectivity, magneto-transport measurements, and microscopy. Gamma-ferrous oxide/silver nano-composites were prepared by a reverse micelle technique and compared to powders made by mechanical milling. The composites' properties were compared to pure nano-phase γ- Fe2O 3 particles and to composites prepared by different techniques to determine changes or enhancements in physical properties. The comparison indicates that the nano-composites' magnetic properties are consistent with the formation of superparamagnetic γ-Fe2O3 nanoparticles. The possible conduction mechanisms explaining the presence of negative magnetoresistance are discussed. Chemically synthesized nano-phase materials were examined for impurity and crystallite size using x-ray diffractometry. Many of the nano-phase materials examined have concentric shell nano-structures with overlapping diffraction patterns. In these cases x-ray diffractometry was used as a screening tool to tune the particular chemical synthesis technique determine the effectiveness of sample annealing on the crystalline structure of the material. Single and mufti-layered thin films were prepared by magnetron sputtering and pulse laser deposition. Their structures are characterized by x-ray reflectivity for layer thickness, critical angle of reflection, surface roughness and interfacial smearing. Structural factors were determined using Fourier analysis and spectral estimation techniques. Results were compared to transmission electron microscopy examination to determine the

  9. Bragg diffraction from magnetic materials

    DEFF Research Database (Denmark)

    Lebech, B.

    2002-01-01

    Neutrons form a penetrating neutral probe, which makes it possible to use neutrons scattering techniques to study bulk materials, localise both light and heavy atoms and to distinguish between isotopes (e.g. hydrogen and deuterium). These properties make neutron scattering complementary to X...... materials. This will be illustrated by reviewing the ordered magnetic structures found in some simple elements and in some chemically more complex systems containing several magnetic elements. The different scattering techniques (two- and three-axis neutron scattering, small angle neutron scattering...

  10. Magnetic characteristics of HPT deformed soft-magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Scheriau, S., E-mail: scheriau@unileoben.ac.a [Christian Doppler Laboratory of Deformation and Fracture, Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben (Austria); Kriegisch, M. [Institute of Solid State Physics, Vienna University of Technology, Vienna (Austria); Kleber, S. [Boehler Edelstahl GmbH, Kapfenberg (Austria); Mehboob, N.; Groessinger, R. [Institute of Solid State Physics, Vienna University of Technology, Vienna (Austria); Pippan, R. [Christian Doppler Laboratory of Deformation and Fracture, Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben (Austria)

    2010-10-15

    Five sets of soft-magnetic metals, such as pure Fe, pure Ni, Fe-3 wt% Si, Fe-6.5 wt% Si and Fe-17 wt% Co, were subjected to high pressure torsion (HPT) up to strain levels where a saturation of the microstructural refinement is observed. Following HPT at 77, 293 and 723 K, transmission electron microscopy (TEM) was used to study the grain size and grain shape of the severely deformed metals. The coercivity H{sub C} was characterized in a magnetic closed system by using ring shaped samples. Magnetic measurements obtained on ring shaped samples give a much higher accuracy for determining the coercivity. Depending on the material the mean microstructural sizes in the steady state vary from 300 nm at 723 K to 30 nm at 77 K, respectively. The coercivity of the deformed materials first increases with decrease in grain size. Once the crystallite size is far below 100 nm the coercivity shows a strong decrease.

  11. Novel functional magnetic materials fundamentals and applications

    CERN Document Server

    2016-01-01

    This book presents current research on advanced magnetic materials and multifunctional composites. Recent advances in technology and engineering have resulted from the development of advanced magnetic materials with improved functional magnetic and magneto-transport properties. Certain industrial sectors, such as magnetic sensors, microelectronics, and security, demand cost-effective materials with reduced dimensionality and desirable magnetic properties such as enhanced magnetic softness, giant magnetic field sensitivity, and large magnetocaloric effect.  Expert chapters present the most up-to-date information on the fabrication process, processing, tailoring of properties, and applications of different families of modern functional materials for advanced smart applications. Topics covered include novel magnetic materials and applications; amorphous and nanocrystalline magnetic materials and applications; hard magnetic materials; magnetic shape memory alloys; and magnetic oxides. The book's highly interdis...

  12. Synthesis and characterization of gadolinium nanostructured materials with potential applications in magnetic resonance imaging, neutron-capture therapy and targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Stefanakis, Dimitrios; Ghanotakis, Demetrios F., E-mail: ghanotakis@chemistry.uoc.g [University of Crete, Department of Chemistry (Greece)

    2010-05-15

    Two Gadolinium nanostructured materials, Gd{sub 2}(OH){sub 5}NO{sub 3} nanoparticles and Gd(OH){sub 3} nanorods, were synthesized and extensively characterized by various techniques. In addition to the potential use of Gd{sub 2}(OH){sub 5}NO{sub 3} in magnetic resonance imaging (MRI) and Neutron-capture therapy (NCT) application, it could also be used in targeted drug delivery. An antibiotic (nalidixic acid), two amino acids (aspartic and glutamic acid), a fatty acid and a surfactant (SDS) were intercalated in the nanoparticles. The surface of the nanoparticles was modified with folic acid in order to be capable of targeted delivery to folate receptor expressing sites, such as tumor human cells.

  13. Cryogenic structural materials for superconducting magnets

    International Nuclear Information System (INIS)

    This paper reviews research in the United States and Japan on structural materials for high-field superconducting magnets. Superconducting magnets are used for magnetic fusion energy devices and for accelerators that are used in particle-physics research. The cryogenic structural materials that we review are used for magnet cases and support structures. We expect increased materials requirements in the future

  14. Magnetic resonance and porous materials

    International Nuclear Information System (INIS)

    Mention the words magnetic resonance to your medical advisor and he or she will immediately think of a multi-million pound scanner that peers deep into the brain. A chemist, on the other hand, will imagine a machine that costs several hundred thousand pounds and produces high-resolution spectra for chemical analysis. Food technologists will probably think of a bench-top instrument for determining moisture content, while an oil prospector will envisage a device that can be operated several kilometres down an oil well. To a physicist the term is more likely to conjure up a mental picture of nuclear spins precessing in a magnetic field. These examples illustrate the diverse aspects of a phenomenon discovered by physicists over 50 years ago. Electron spin resonance was first discovered by Russian scientists, and nuclear magnetic resonance was discovered in the US shortly afterwards by Ed Purcell at Harvard University and Felix Bloch at Stanford University. Today, nuclear magnetic resonance (NMR) is the most widely used technique. Modern NMR machines are making it possible to probe microstructure and molecular movement in materials as diverse as polymers, cements, rocks, soil and foods. NMR allows the distribution of different components in a material to be determined with a resolution approaching 1μm, although the signal can be sensitive to even smaller lengthscales. In this article the authors describe how physicists are still developing magnetic resonance to exploit a range of new applications. (UK)

  15. Magnetic molecular materials with paramagnetic lanthanide ions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The diverse magnetic properties of lanthanide-based magnetic molecular materials are introduced in the following organization.First,the general aspects of magnetic molecular materials and electronic states of lanthanide ions are introduced.Then the structures and magnetic properties are described and analyzed for molecules with one lanthanide ion,4f-4f,4f-3d and 4f-p magnetic coupling interactions.In each section,magnetic coupling,magnetic ordering and magnetic relaxation phenomenon are briefly reviewed using some examples.Finally,some possibilities of developing magnetic molecular materials containing lanthanide ions are discussed in the outlook part.

  16. Fundamentals and applications of magnetic materials

    CERN Document Server

    Krishnan, Kannan M

    2016-01-01

    Students and researchers looking for a comprehensive textbook on magnetism, magnetic materials and related applications will find in this book an excellent explanation of the field. Chapters progress logically from the physics of magnetism, to magnetic phenomena in materials, to size and dimensionality effects, to applications. Beginning with a description of magnetic phenomena and measurements on a macroscopic scale, the book then presents discussions of intrinsic and phenomenological concepts of magnetism such as electronic magnetic moments and classical, quantum, and band theories of magnetic behavior. It then covers ordered magnetic materials (emphasizing their structure-sensitive properties) and magnetic phenomena, including magnetic anisotropy, magnetostriction, and magnetic domain structures and dynamics. What follows is a comprehensive description of imaging methods to resolve magnetic microstructures (domains) along with an introduction to micromagnetic modeling. The book then explores in detail size...

  17. Materials Characterization Center program plan

    International Nuclear Information System (INIS)

    The Materials Characterization Center (MCC) has been established at Pacific Northwest Laboratory as part of the Materials Characterization Organization for providing an authoritative, referenceable basis for establishing nuclear waste material properties and test methods. The MCC will provide a data base that will include information on the components of the waste emplacement package - the spent fuel or processed waste form and the engineered barriers - and their interaction with each other and as affected by the environment. The MCC will plan materials testing, develop and document procedures, collect and analyze existing materials data, and conduct tests as necessary

  18. Applied research on amorphous magnetic materials

    International Nuclear Information System (INIS)

    Amorphous magnetic materials are increasingly becoming an industrial reality, which a variety of applications to electronics and electrical engineering. Many research lines are in progress for what concerns the production techniques, the understanding of the structure and properties of amorphous ribbons, the optimization and extension of their applications. The fast quenching methods used to obtain amorphous materials will first be reviewed, also describing an experimental apparatus set up by the authors for laboratory investigations of rapid solidification processes. Because of the non equilibrium structure of amorphous metallic alloys, various relaxation effects are expected to occur, which may partially limit the use of these materials. Studies of these relaxation phenomena, performed by different methods, including Moessbauer spectroscopy will also be reviewed, showing their importance in better understanding the amorphous structure. Finally much attention will be devoted to actual applications of amorphous magnetic materials. Emphasis will be placed on the prospective applications of amorphous ribbons characterized by very low power losses to magnetic cores of distribution transformers, pointing to the possible advantages, but also to the technical problems involved with the substitution of crystalline laminations with the new amorphous materials. (orig.)

  19. New rare earth-based magnetocaloric materials for magnetic refrigeration

    OpenAIRE

    Mayer, Charlotte

    2011-01-01

    The studies presented in this manuscript deal with the synthesis and characterization of new rare-earth based magnetocaloric materials for magnetic refrigeration applications. The first chapter is an introduction to the concepts of magnetocaloric effect and magnetic refrigeration and establishes a review of the magnetocaloric materials existing today. Two research axes were explored in order to obtain materials with a high refrigeration capacity (RC) and to identify strategies for improving t...

  20. Materials for Room Temperature Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl

    Magnetic refrigeration is a cooling method, which holds the promise of being cleaner and more efficient than conventional vapor-compression cooling. Much research has been done during the last two decades on various magnetic materials for this purpose and today a number of materials are considered...... candidates as they fulfill many of the requirements for a magnetic refrigerant. However, no one material stands out and the field is still active with improving the known materials and in the search for a better one. Magnetic cooling is based on the magnetocaloric effect, which causes a magnetic material to...... change its temperature when a magnetic field is applied or removed. For room temperature cooling, one utilizes that the magnetocaloric effect peaks near magnetic phase transitions and so the materials of interest all have a critical temperature within the range of 250 – 310 K. A magnetic refrigerant...

  1. Material stabilization characterization management plan

    International Nuclear Information System (INIS)

    This document presents overall direction for characterization needs during stabilization of SNM at the Plutonium Finishing Plant (PFP). Technical issues for needed data and equipment are identified. Information on material categories and links to vulnerabilities are given. Comparison data on the material categories is discussed to assist in assessing the relative risks and desired processing priority

  2. Hybrid nanostructured materials with tunable magnetic characteristics

    International Nuclear Information System (INIS)

    We report on the development of hybrid nanostructured materials (HNM) based on spinel-metal-oxide nanoparticles (SMON) stabilized in carboxymethyl-cellulose (CMC)/cetyltrimethyl-ammonium-bromide (CTAB) templates, with tunable magnetic characteristics. These HNM were synthesized using a one-pot chemical approach to obtain CMC/CTAB templates with controllable size and morphology, where the SMON could be densely arranged. The synthesized HNM were characterized by transmission electron microscopy and its related techniques, such as bright field (BF) and Z-contrast (HAADF-STEM) imaging, and selected area electron diffraction, as well as static magnetic measuring. Experimental evidence suggests that the morphology and size of the CMC/CTAB templates are highly dependent on the weight ratio of CTAB:SMON, as well as the hydration days of the CMC that is used for the synthesis of the HNM. Controlling these parameters allows modifying the density of the SMON arrangement in the CMC/CTAB templates. Moreover, magnetic features such as remanence, coercivity, and blocking/de-blocking processes of the particles’ magnetic moments are highly dependent on the interactions among the SMON assembled in the templates. Hence, the magnetic characteristics of HNM can be modulated or tuned by controlling the manner the SMON are arranged within the CMC/CTAB templates

  3. Physics and measurements of magnetic materials

    CERN Document Server

    Sgobba, S

    2010-01-01

    Magnetic materials, both hard and soft, are used extensively in several components of particle accelerators. Magnetically soft iron-nickel alloys are used as shields for the vacuum chambers of accelerator injection and extraction septa; Fe-based material is widely employed for cores of accelerator and experiment magnets; soft spinel ferrites are used in collimators to damp trapped modes; innovative materials such as amorphous or nanocrystalline core materials are envisaged in transformers for high-frequency polyphase resonant convertors for application to the International Linear Collider (ILC). In the field of fusion, for induction cores of the linac of heavy-ion inertial fusion energy accelerators, based on induction accelerators requiring some 107 kg of magnetic materials, nanocrystalline materials would show the best performance in terms of core losses for magnetization rates as high as 105 T/s to 107 T/s. After a review of the magnetic properties of materials and the different types of magnetic behaviour...

  4. A biocompatible magnetic film: synthesis and characterization

    OpenAIRE

    Chatterjee, Jhunu; Haik, Yousef; Chen, Ching Jen

    2004-01-01

    Background Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. Methods A biocompatible magnetic gel film has been synthesized using polyvinyl alcohol. The magnetic gel was dried to generate a biocompatible magnetic film. Nanosized iron oxide particles (γ-Fe2O3, ~7 nm) have been used to produce the magnetic gel. Results The surface ...

  5. Magnetic materials fundamentals, products, properties, applications

    CERN Document Server

    Hilzinger, Rainer

    2013-01-01

    At a practical level, this compendium reviews the basics of soft and hard magnetic materials, discusses the advantages of the different processing routes for the exploitation of the magnetic properties and hence assists in proper, fail-safe and economic application of magnetic materials. Essential guidelines and formulas for the calculation of the magnetic and electrical properties, temperature and long-term stability of permanent magnets, of inductive components and magnetic shielding are compiled. Selected fields of application and case studies illustrate the large diversity of technical applications. Application engineers will appreciate the comprehensive compilation of the properties and detailed characteristic curves of modern soft and hard magnetic materials. Materials scientists will enjoy the presentation of the different processing routes and their impact on the magnetic properties and students will profit from the survey from the basics of magnetism down to the applications in inductive components, ...

  6. Magnetic imaging and its applications to materials

    CERN Document Server

    De Graef, Marc

    2000-01-01

    Volume 36 provides an extensive introduction to magnetic imaging,including theory and practice, utilizing a wide range of magnetic sensitive imaging methods. It also illustrates the applications of these modern experimental techniques together with imaging calculations to today's advanced magnetic materials. This book is geared towards the upper-level undergraduate students and entry-level graduate students majoring in physics or materials science who are interested in magnetic structure and magnetic imaging. Researchers involved in studying magnetic materials should alsofind the book usef

  7. Magnetic viscosity studies in hard magnetic materials

    International Nuclear Information System (INIS)

    The magnetic viscosity behavior has been studied in several hard magnets with different magnetization reversal mechanisms including barium ferrite powders, Cu-Mn-Al, ferrite magnets, Nd-Fe-B, and SmCo5, Sm2(Co,Fe,Cu,Zr)17. The measurements were made with a vibrating sample magnetometer for times up to 60 s and a SQUID magnetometer for longer times in the range of 60--2300 s. For most of the samples the magnetization was found to vary logarithmically with time. The field and temperature dependence of the magnetic viscosity coefficient S was studied. Here, S was found to vary with the applied field and it usually peaked around the coercive field Hc. The measured values of Smax at 10 K range from 0.004 to 1.853 emu/g for Cu-Mn-Al and Sm2(Co,Fe,Cu,Zr)17, respectively. The magnetic viscosity coefficient was used together with the magnetic susceptibility to determine the activation volume

  8. Anisotropy of Magnetic Properties in Textured Materials

    OpenAIRE

    J. A. Szpunar

    1989-01-01

    A short survey is presented of techniques and methods used to correlate the texture with the magnetic anisotropy of various properties of soft and hard magnetic materials. Also, examples of magnetic materials are discussed with emphasis on techniques of processing which optimize the texture.

  9. Materials for room temperature magnetic refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl Hansen, B.

    2010-07-15

    Magnetic refrigeration is a cooling method, which holds the promise of being cleaner and more efficient than conventional vapor-compression cooling. Much research has been done during the last two decades on various magnetic materials for this purpose and today a number of materials are considered candidates as they fulfill many of the requirements for a magnetic refrigerant. However, no one material stands out and the field is still active with improving the known materials and in the search for a better one. Magnetic cooling is based on the magnetocaloric effect, which causes a magnetic material to change its temperature when a magnetic field is applied or removed. For room temperature cooling, one utilizes that the magnetocaloric effect peaks near magnetic phase transitions and so the materials of interest all have a critical temperature within the range of 250 - 310 K. A magnetic refrigerant should fulfill a number of criteria, among these a large magnetic entropy change, a large adiabatic temperature change, preferably little to no thermal or magnetic hysteresis and the material should have the stability required for long term use. As the temperature range required for room temperature cooling is some 40 - 50 K, the magnetic refrigerant should also be able to cover this temperature span either by exhibiting a very broad peak in magnetocaloric effect or by providing the opportunity for creating a materials series with varying transition temperatures. (Author)

  10. Rapid Characterization of Magnetic Moment of Cells for Magnetic Separation

    OpenAIRE

    Ooi, Chinchun; Earhart, Christopher M.; Wilson, Robert J.; Wang, Shan X.

    2013-01-01

    NCI-H1650 lung cancer cell lines labeled with magnetic nanoparticles via the Epithelial Cell Adhesion Molecule (EpCAM) antigen were previously shown to be captured at high efficiencies by a microfabricated magnetic sifter. If fine control and optimization of the magnetic separation process is to be achieved, it is vital to be able to characterize the labeled cells’ magnetic moment rapidly. We have thus adapted a rapid prototyping method to obtain the saturation magnetic moment of these cells....

  11. Magnetic susceptibility, magnetization, magnetic moment and characterization of Carancas meteorite

    CERN Document Server

    Rosales, Domingo

    2015-01-01

    On September, 15th, 2007, in the community of Carancas (Puno, Peru) a stony meteorite formed a crater explosive type with a mean diameter of 13.5 m. some samples meteorite fragments were collected. The petrologic analysis performed corresponds to a meteorite ordinary chondrite H 4-5. In this paper we have analyzed the magnetic properties of a meteorite fragment with a proton magnetometer. Also in order to have a complete characterization of the Carancas meteorite and its crater, from several papers, articles and reports, we have made a compilation of the most important characteristics and properties of this meteorite.

  12. Preliminary characterization of iron-containing material and of neuronal assembles responsive to magnetic stimulation in the monarch butterfly (Danaus plexippus)

    Science.gov (United States)

    Fuentes, A.; Barrera, J.; Rizi, A.; Urrutia, J.; Gutierrez, G.

    2007-05-01

    Migration is a common process among animal groups. Most of the biological events underlying migratory behavior are yet unknown. This is especially true for the neural mechanisms and the sensory information used by migratory species to define their routes. Hence, the present work aimed at demonstrating that the Monarch butterflies (Danaus plexippus) may use magnetic cues to define their route of migration by mapping neuronal assembles responsive to magnetic stimuli. Because research conducted in other insect species suggests that magnetite-based receptors may transduce the magnetic information into neuronal codes, we also evaluated the presence of magnetite in the body of the monarch butterfly. Our electron microscopy results demonstrate that the butterfly's head, abdomen and thorax contain iron particles of about 1-5 mm in diameter. Accordingly, Prussian blue histochemical techniques revealed the presence of abundant ferric deposits in diverse regions of the nervous system and the ventral abdomen. In contrast, the thoracic segments have only a few deposits. Finally, magneto metric measures concord with the morphological results. With regard to the mapping of the neuronal assembles responsive to magnetic stimuli, we were able to revealed c-fos immunoreactivity in groups of neurons located in the retina, lamina, lobula and deutero-cerebrum in butterflies subjected to magnetic stimuli. In sum, we believe that our results provide preliminary evidence supporting the existence of 1) a neural pathway capable of processing magnetic information in the monarch butterfly and 2) the presence of magnetite-like material in the various segments of its body.

  13. Electron Spectroscopy for Material Characterization

    OpenAIRE

    Süzer, Şefik

    1998-01-01

    Basic principles of the two electron spectroscopic techniques, the x-ray photoelectron spectroscopy, XPS, and the Auger electron spectroscopy, AES, are given. Their utilization in material characterization are introduced through examples with application of these techniques to various surface related problems.

  14. FTIR characterization of advanced materials

    Science.gov (United States)

    Young, P. R.; Chang, A. C.

    1986-01-01

    This paper surveys the application of Fourier transform infrared spectroscopy to the characterization of advanced materials. FTIR sampling techniques including internal and external reflectance and photoacoustic spectroscopy are discussed. Representative examples from the literature of the analysis of resins, fibers, prepregs and composites are reviewed. A discussion of several promising specialized FTIR techniques is also presented.

  15. Modern magnetic materials principles and applications

    CERN Document Server

    O'Handley, Robert C

    2000-01-01

    A truly modern treatment of materials that can hold a magnetic field. Covers cutting-edge materials with many important technical applications. Includes examples and problems along with computer solutions.

  16. Magnetism and Structure in Functional Materials

    CERN Document Server

    Planes, Antoni; Saxena, Avadh

    2005-01-01

    Magnetism and Structure in Functional Materials addresses three distinct but related topics: (i) magnetoelastic materials such as magnetic martensites and magnetic shape memory alloys, (ii) the magnetocaloric effect related to magnetostructural transitions, and (iii) colossal magnetoresistance (CMR) and related magnanites. The goal is to identify common underlying principles in these classes of materials that are relevant for optimizing various functionalities. The emergence of apparently different magnetic/structural phenomena in disparate classes of materials clearly points to a need for common concepts in order to achieve a broader understanding of the interplay between magnetism and structure in this general class of new functional materials exhibiting ever more complex microstructure and function. The topic is interdisciplinary in nature and the contributors correspondingly include physicists, materials scientists and engineers. Likewise the book will appeal to scientists from all these areas.

  17. Quantitative Characterization of Nanostructured Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Frank (Bud) Bridges, University of California-Santa Cruz

    2010-08-05

    The two-and-a-half day symposium on the "Quantitative Characterization of Nanostructured Materials" will be the first comprehensive meeting on this topic held under the auspices of a major U.S. professional society. Spring MRS Meetings provide a natural venue for this symposium as they attract a broad audience of researchers that represents a cross-section of the state-of-the-art regarding synthesis, structure-property relations, and applications of nanostructured materials. Close interactions among the experts in local structure measurements and materials researchers will help both to identify measurement needs pertinent to real-world materials problems and to familiarize the materials research community with the state-of-the-art local structure measurement techniques. We have chosen invited speakers that reflect the multidisciplinary and international nature of this topic and the need to continually nurture productive interfaces among university, government and industrial laboratories. The intent of the symposium is to provide an interdisciplinary forum for discussion and exchange of ideas on the recent progress in quantitative characterization of structural order in nanomaterials using different experimental techniques and theory. The symposium is expected to facilitate discussions on optimal approaches for determining atomic structure at the nanoscale using combined inputs from multiple measurement techniques.

  18. A biocompatible magnetic film: synthesis and characterization

    Science.gov (United States)

    Chatterjee, Jhunu; Haik, Yousef; Chen, Ching Jen

    2004-01-01

    Background Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. Methods A biocompatible magnetic gel film has been synthesized using polyvinyl alcohol. The magnetic gel was dried to generate a biocompatible magnetic film. Nanosized iron oxide particles (γ-Fe2O3, ~7 nm) have been used to produce the magnetic gel. Results The surface morphology and magnetic properties of the gel films were studied. The iron oxide particles are superparamagnetic and the gel film also showed superparamagnetic behavior. Conclusion Magnetic gel made out of crosslinked magnetic nanoparticles in the polymer network was found to be stable and possess the magnetic properties of the nanoparticles. PMID:14761251

  19. Materials with low DC magnetic susceptibility for sensitive magnetic measurements

    CERN Document Server

    Khatiwada, Rakshya; Kendrick, Rachel; Khosravi, Marjan; Peters, Michael; Smith, Erick; Snow, Mike

    2015-01-01

    Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium-indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10^-9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within...

  20. Materials with low DC magnetic susceptibility for sensitive magnetic measurements

    Science.gov (United States)

    Khatiwada, R.; Dennis, L.; Kendrick, R.; Khosravi, M.; Peters, M.; Smith, E.; Snow, W. M.

    2016-02-01

    Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium-indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10-9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within experimental error. These results verify the well-known Wiedemann additivity law for the magnetic susceptibility of inert mixtures of materials and thereby realize the ability to produce materials with small but tunable magnetic susceptibility. For our particular scientific application, we are also looking for materials with the largest possible number of neutrons and protons per unit volume. The gallium-indium alloys fabricated and measured in this work possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature liquid, and the tungsten-bismuth pressed powder mixtures possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature solid. This ratio is a figure of merit for a certain class of precision experiments that search for possible exotic spin-dependent forces of Nature.

  1. Surface characterization of ceramic materials

    International Nuclear Information System (INIS)

    In recent years several techniques have become available to characterize the structure and chemical composition of surfaces of ceramic materials. These techniques utilize electron scattering and scattering of ions from surfaces. Low-energy electron diffraction is used to determine the surface structure, Auger electron spectroscopy and other techniques of electron spectroscopy (ultraviolet and photoelectron spectroscopies) are employed to determine the composition of the surface. In addition the oxidation state of surface atoms may be determined using these techniques. Ion scattering mass spectrometry and secondary ion mass spectrometry are also useful in characterizing surfaces and their reactions. These techniques, their applications and the results of recent studies are discussed. 12 figures, 52 references, 2 tables

  2. FNAS materials processing and characterization

    Science.gov (United States)

    Golben, John P.

    1991-01-01

    Research on melt-sintered high temperature superconducting materials is presented. The vibrating sample magnetometer has become a useful characterization tool for the study of high temperature superconductors. Important information regarding the superconducting properties of a sample can be obtained without actually making contact with the sample itself. A step toward microgravity processing of high temperature superconductors was taken. In the future, the samples need to be optimized prior to this processing of the sample before the specific effects of the microgravity environment can be isolated. A series of melt-sintered samples show that bulk processing of high temperature superconductors is getting better.

  3. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation

    International Nuclear Information System (INIS)

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 μm with 4 wt.% over 100 μm and content metallic iron of 93 wt%. (author)

  4. Soft and hard nanostructured magnetic materials

    International Nuclear Information System (INIS)

    Tailoring of soft and hard magnetic materials can be performed by nanocrystallisation. Random anisotropy and intergranular exchange govern the macroscopic properties of nanocrystalline ferromagnets. The nature and topology of the intergranular region, matrix or grain boundaries, determine the degree of intergranular coupling. Important information about magnetic and topological properties of grain boundaries can be inferred from Moessbauer spectroscopy. The state of the art of those tailored materials is reviewed paying special attention to the correlation between nanostructure and macroscopic properties

  5. Thermoinduced magnetization in nanoparticles of antiferromagnetic materials

    DEFF Research Database (Denmark)

    Mørup, Steen; Frandsen, Cathrine

    2004-01-01

    We show that there is a thermoinduced contribution to the magnetic moment of nanoparticles of antiferromagnetic materials. It arises from thermal excitations of the uniform spin-precession mode, and it has the unusual property that its magnitude increases with increasing temperature. This has...... the consequence that antiferromagnetism is nonexistent in nanoparticles at finite temperatures and it explains magnetic anomalies, which recently have been reported in a number of studies of nanoparticles of antiferromagnetic materials....

  6. Thermal Casimir Force between Magnetic Materials

    OpenAIRE

    Klimchitskaya, G. L.; Geyer, B.; Mostepanenko, V. M.

    2009-01-01

    We investigate the Casimir pressure between two parallel plates made of magnetic materials at nonzero temperature. It is shown that for real magnetodielectric materials only the magnetic properties of ferromagnets can influence the Casimir pressure. This influence is accomplished through the contribution of the zero-frequency term of the Lifshitz formula. The possibility of the Casimir repulsion through the vacuum gap is analyzed depending on the model used for the description of the dielectr...

  7. Handbook of magnetic materials, v. 19

    CERN Document Server

    2011-01-01

    Volume 19 of the Handbook of Magnetic Materials, as the preceding volumes, has a dual purpose. As a textbook it is intended to help those who wish to be introduced to a given topic in the field of magnetism without the need to read the vast amount of literature published. As a work of reference it is intended for scientists active in magnetism research. To this dual purpose, Volume 19 is composed of topical review articles written by leading authorities. In each of these articles an extensive description is given in graphical as well as in tabular form, much emphasis being placed on the discussion of the experimental material in the framework of physics, chemistry and material science. It provides readers with novel trends and achievements in magnetism.

  8. Magnetization and magnetostriction in highly magnetostrictive materials

    International Nuclear Information System (INIS)

    The majority of this research has been in developing a model to describe the magnetostrictive properties of Terfenol-D, Tb1-xDyxFey (x = 0.7-0.75 and y = 1.8--2.0), a rare earth-iron alloy which displays much promise for use in device applications. In the first chapter an introduction is given to the phenomena of magnetization and magnetostriction. The magnetic processes responsible for the observed magnetic properties of materials are explained. An overview is presented of the magnetic properties of rare earths, and more specifically the magnetic properties of Terfenol-D. In the second chapter, experimental results are presented on three composition of Tb1-xDyxFey with x = 0.7, y= 1.9, 1.95, and x= 0.73, y= 1.95. The data were taken for various levels of prestress to show the effects of composition and microstructure on the magnetic and magnetostrictive properties of Terfenol-D. In the third chapter, a theoretical model is developed based on the rotation of magnetic domains. The model is used to explain the magnetic and magnetostrictive properties of Terfenol-D, including the observed negative strictions and large change in strain. The fourth chapter goes on to examine the magnetic properties of Terfenol-D along different crystallographic orientations. In the fifth chapter initial data are presented on the time dependence of magnetization in nickel

  9. Designing magnetic composite materials using aqueous magnetic fluids

    CERN Document Server

    Galicia, J A; Cousin, F; Guemghar, D; Menager, C; Cabuil, V

    2003-01-01

    In this paper, we report on how to take advantage of good knowledge of both the chemistry and the stability of an aqueous magnetic colloidal suspension to realize different magnetic composites. The osmotic pressure of the magnetic nanoparticles is set prior to the realization of the composite to a given value specially designed for the purpose for each hybrid material: magnetic particles in polymer networks, particles as probes for studying the structure of clay suspensions and shape modification of giant liposomes. First, we show that the introduction of magnetic particles in polyacrylamide gels enhances their Young modulus and reduces the swelling caused by water. The particles cause both a mechanical and an osmotic effect. The latter is strongly dependent on the ionic strength and is attributed to an attraction between particles and the polymeric matrix. In the second part, we determine the microscopic structure of suspensions of laponite as a function of concentration, by combining SANS and magneto-optica...

  10. Superconductivity and magnetism: Materials properties and developments

    International Nuclear Information System (INIS)

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.Tc superconductivity, magnetic superconductors, MgB2, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  11. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N.H.; Bay, N.; Grivel, J.C. (eds.) [and others

    2003-07-01

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.T{sub c} superconductivity, magnetic superconductors, MgB{sub 2}, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  12. Synthesis and characterization of functionalized magnetic nanoparticles

    Science.gov (United States)

    Biswal, Dipti; Peeples, Brianna N.; Spence, Destiny D.; Peeples, Caryn; Bell, Crystal N.; Pradhan, A. K.

    2012-04-01

    Magnetic nanoparticles have been used in a wide array of industrial and biomedical applications due to their unique properties at the nanoscale level. They are extensively used in magnetic resonance imaging (MRI), magnetic hyperthermia treatment, drug delivery, and in assays for biological separations. Furthermore, superparamagnetic nanoparticles are of large interest for in vivo applications. However, these unmodified nanoparticles aggregate and consequently lose their superparamagnetic behaviors, due to high surface to volume ratio and strong dipole to dipole interaction. For these reasons, surface coating is necessary for the enhancement and effectiveness of magnetic nanoparticles to be used in various applications. In addition to providing increased stability to the nanoparticles in different solvents or media, stabilizers such as surfactants, organic/inorganic molecules, polymer and co-polymers are employed as surface coatings, which yield magnetically responsive systems. In this work we present the synthesis and magnetic characterization of Fe3O4 nanoparticles coated with 3-aminopropyltriethoxy silane (APS) and citric acid. The particles magnetic hysteresis was measured by a superconducting quantum interference device (SQUID) magnetometer with an in-plane magnetic field. The uncoated and coated magnetic nanoparticles were characterized by using fourier transform infrared (FTIR), UV-vis, X-ray diffraction, transmission electron microscopy, and thermo-gravimetric analysis.

  13. Magnetic characterization of isolated candidate vertebrate magnetoreceptor cells.

    Science.gov (United States)

    Eder, Stephan H K; Cadiou, Hervé; Muhamad, Airina; McNaughton, Peter A; Kirschvink, Joseph L; Winklhofer, Michael

    2012-07-24

    Over the past 50 y, behavioral experiments have produced a large body of evidence for the existence of a magnetic sense in a wide range of animals. However, the underlying sensory physiology remains poorly understood due to the elusiveness of the magnetosensory structures. Here we present an effective method for isolating and characterizing potential magnetite-based magnetoreceptor cells. In essence, a rotating magnetic field is employed to visually identify, within a dissociated tissue preparation, cells that contain magnetic material by their rotational behavior. As a tissue of choice, we selected trout olfactory epithelium that has been previously suggested to host candidate magnetoreceptor cells. We were able to reproducibly detect magnetic cells and to determine their magnetic dipole moment. The obtained values (4 to 100 fAm(2)) greatly exceed previous estimates (0.5 fAm(2)). The magnetism of the cells is due to a μm-sized intracellular structure of iron-rich crystals, most likely single-domain magnetite. In confocal reflectance imaging, these produce bright reflective spots close to the cell membrane. The magnetic inclusions are found to be firmly coupled to the cell membrane, enabling a direct transduction of mechanical stress produced by magnetic torque acting on the cellular dipole in situ. Our results show that the magnetically identified cells clearly meet the physical requirements for a magnetoreceptor capable of rapidly detecting small changes in the external magnetic field. This would also explain interference of ac powerline magnetic fields with magnetoreception, as reported in cattle. PMID:22778440

  14. Thermodynamic measurements of applied magnetic materials

    OpenAIRE

    Cooke, David William

    2010-01-01

    The specific heat of a material offers a host of information about the energetics of the system, from the phonons and electrons to phase changes in the material and two-state systems. In order to measure the specific heat of small samples such as quenched high pressure materials or thin films, one must turn to microcalorimetry. This thesis discusses the application of microcalorimetry to small magnetic samples and the underlying physics illuminated by the technique.The thesis first describe...

  15. Magnetic and Superconducting Materials at High Pressures

    Energy Technology Data Exchange (ETDEWEB)

    Struzhkin, Viktor V. [Carnegie Inst. of Washington, Washington, DC (United States)

    2015-03-24

    The work concentrates on few important tasks in enabling techniques for search of superconducting compressed hydrogen compounds and pure hydrogen, investigation of mechanisms of high-Tc superconductivity, and exploring new superconducting materials. Along that route we performed several challenging tasks, including discovery of new forms of polyhydrides of alkali metal Na at very high pressures. These experiments help us to establish the experimental environment that will provide important information on the high-pressure properties of hydrogen-rich compounds. Our recent progress in RIXS measurements opens a whole field of strongly correlated 3d materials. We have developed a systematic approach to measure major electronic parameters, like Hubbard energy U, and charge transfer energy Δ, as function of pressure. This technique will enable also RIXS studies of magnetic excitations in iridates and other 5d materials at the L edge, which attract a lot of interest recently. We have developed new magnetic sensing technique based on optically detected magnetic resonance from NV centers in diamond. The technique can be applied to study superconductivity in high-TC materials, to search for magnetic transitions in strongly correlated and itinerant magnetic materials under pressure. Summary of Project Activities; development of high-pressure experimentation platform for exploration of new potential superconductors, metal polyhydrides (including newly discovered alkali metal polyhydrides), and already known superconductors at the limit of static high-pressure techniques; investigation of special classes of superconducting compounds (high-Tc superconductors, new superconducting materials), that may provide new fundamental knowledge and may prove important for application as high-temperature/high-critical parameter superconductors; investigation of the pressure dependence of superconductivity and magnetic/phase transformations in 3d transition metal compounds, including

  16. Characterization of minerals, metals and materials

    CERN Document Server

    Hwang, Jiann-Yang; Bai, Chengguang; Carpenter, John; Cai, Mingdong; Firrao, Donato; Kim, Byoung-Gon

    2012-01-01

    This state-of-the-art reference contains chapters on all aspects of the characterization of minerals, metals, and materials. The title presents papers from one of the largest yearly gatherings of materials scientists in the world and thoroughly discusses the characterization of minerals, metals, and materials The scope includes current industrial applications and research and developments in the following areas:  Characterization of Ferrous Metals Characterization of Non-Ferrous Materials Characterization of Minerals and Ceramics Character

  17. Nondestructive methods for materials characterization. Materials Research Society symposium proceedings, Volume 591

    International Nuclear Information System (INIS)

    The symposium, Nondestructive Methods for Materials Characterization, was held at the Materials Research Society 1999 Fall Meeting on November 29--30 in Boston, Massachusetts. The papers focused on advanced nondestructive evaluation (NDE) methodologies and instrumentation. Several X-ray techniques were developed or tailored for process control and deformation behavior in high- and low-density materials. Fracture, fatigue, and corrosion behavior of aging aircraft materials were characterized via linear and nonlinear acoustics. Structure-sensitive properties in magnetic materials and building materials were gauged with NDE parameters. Electric and dielectric properties in ceramics and composite materials were established. Thickness and interface properties in silicon wafers and thin films were studied. Advanced optical and infrared techniques were investigated for the characterization of capacitance, circuit boards, laser diodes, and material growth. Thirty five papers were processed separately for inclusion on the data base

  18. Nondestructive methods for materials characterization. Materials Research Society symposium proceedings, Volume 591

    Energy Technology Data Exchange (ETDEWEB)

    Baaklini, G.Y.; Meyendorf, N.; Matikas, T.E.; Gilmore, R.S. [eds.

    2000-07-01

    The symposium, Nondestructive Methods for Materials Characterization, was held at the Materials Research Society 1999 Fall Meeting on November 29--30 in Boston, Massachusetts. The papers focused on advanced nondestructive evaluation (NDE) methodologies and instrumentation. Several X-ray techniques were developed or tailored for process control and deformation behavior in high- and low-density materials. Fracture, fatigue, and corrosion behavior of aging aircraft materials were characterized via linear and nonlinear acoustics. Structure-sensitive properties in magnetic materials and building materials were gauged with NDE parameters. Electric and dielectric properties in ceramics and composite materials were established. Thickness and interface properties in silicon wafers and thin films were studied. Advanced optical and infrared techniques were investigated for the characterization of capacitance, circuit boards, laser diodes, and material growth. Thirty five papers were processed separately for inclusion on the data base.

  19. Focus on Materials Analysis and Processing in Magnetic Fields

    OpenAIRE

    Yoshio Sakka, Noriyuki Hirota, Shigeru Horii and Tsutomu Ando

    2009-01-01

    Recently, interest in the applications of feeble (diamagnetic and paramagnetic) magnetic materials has grown, whereas the popularity of ferromagnetic materials remains steady and high. This trend is due to the progress of superconducting magnet technology, particularly liquid-helium-free superconducting magnets that can generate magnetic fields of 10 T and higher. As the magnetic energy is proportional to the square of the applied magnetic field, the magnetic energy of such 10 T magnets is in...

  20. Magnetic separation of uranium from waste materials

    International Nuclear Information System (INIS)

    Criteria were developed for selection of candidate wastes for testing magnetic separation of uranium and/or other paramagnetic materials. A survey of Department of Energy (DOE) hazardous wastes was conducted to determine good candidates for bench-scale magnetic separation tests. Representatives of 21 DOE sites were contacted, and materials were identified as potential candidates for magnetic separation. To date, seven samples have been obtained and tested for separability of uranium with a bench-scale magnetic assaying device. The samples tested have been obtained from the K-1401B and K-1401C ponds in Oak Ridge, Tennessee; from waste piles in Maywood, New Jersey; from North and South Ponds in Richland, Washington; and from magnesium fluoride drums in Fernald, Ohio. The magnetic device utilized in these tests can be used in a deflective mode with dry particulate samples or a matrix-gradient mode with either dry particulate or liquid-suspended materials. Uranium separation from magnesium fluoride has shown exceptionally good performance in both wet and dry systems and could be an important application of the technology. 13 figs., 6 tabs

  1. High performance of low cost soft magnetic materials

    Indian Academy of Sciences (India)

    Josefina M Silveyra; Emília Illeková; Marco Coïsson; Federica Celegato; Franco Vinai; Paola Tiberto; Javier A Moya; Victoria J Cremaschi

    2011-12-01

    The consistent interest in supporting research and development of magnetic materials during the last century is revealed in their steadily increasing market. In this work, the soft magnetic nanocrystalline FINEMET alloy was prepared with commercial purity raw materials and compared for the first time with the generally studied high purity one. The exhaustive characterization covers several diverse techniques: X-ray diffraction, Mössbauer spectroscopy, differential scanning calorimetry, differential thermal analysis and magnetic properties. In addition, a brief economic analysis is presented. For the alloys annealed at 813 K, the value of the grain size was 16 nm with 19.5% of Si, the coercivity was 0.30 A m-1 while the saturation was 1.2 T. These results prove that structural, magnetic and thermal properties of this material are very close to the expensive high purity FINEMET alloy, while a cost reduction of almost 98% seems highly attractive for laboratories and industry. The analysis should be useful not only for the production of FINEMETs, but for other type of systems with similar constitutive elements as well, including soft and hard magnetic materials.

  2. Structure and magnetic properties of powder soft magnetic materials

    Directory of Open Access Journals (Sweden)

    J. Konieczny

    2007-01-01

    Full Text Available Purpose: The paper presents influence of high-energy mechanical milling process, isothermal annealing and toa combination of these two technologies of cobalt base metallic glasses Co77Si11.5B11.5 on magnetic propertiesand their structure.Design/methodology/approach: The powder test piece obtained from the input amorphous ribbon in highenergyball milling. The diffraction examinations and examinations of thin foils were made on the JEOL JEM200CX transmission electron microscope. Observations of the structure of powders were made on the OptonDSM-940 scanning electron microscope. The X-ray tests were realized with the use of the XRD 7 SEIFERTFPMdiffractometer.Findings: analysis of the magnetic properties test results of the of the Co77Si11.5B11.5 powders obtained inthe high-energy ball of milling process proved that the process causes significant decrease in the magneticproperties. The structure and magnetic properties of this material may be improved by means of a proper choiceof parameters of this process as well as the final thermal treatment.Research limitations/implications: For the powders, further magnetical, structure and composition examinationsare planed.Practical implications: The amorphous and nanocrystalline metal powders obtained by high-energy ballmilling of metallic glasses feature an alternative to solid alloys and make it possible to obtain the ferromagneticnanocomposites, whose shape and dimensions can be freely formed.Originality/value: The paper presents influence of parameters of the high-energy ball milling process onstructure and magnetic properties of soft magnetic powder materials obtained in this technique. Results and adiscussion of the influence of high energy mechanical milling process on particle size and their distribution aswell as structure and magnetic properties of investigated samples is presented.

  3. Characterization of Nd-Dy-Fe-B sintered magnets

    International Nuclear Information System (INIS)

    In this paper we study the production and characterization of sintered Nd-Dy-Fe-B magnets. The magnetic characterization is discussed. The effect of sintering temperature on grain size and magnetic properties of isotropic magnets is considered. Finally, we determine the degree of crystallite orientation for an anisotropic magnet. (author)

  4. Magnetic materials. Trend in magnetic materials, expectations for synchrotron beam, neutron and muon

    International Nuclear Information System (INIS)

    Recently, to obtain higher performance both soft and hard magnetic materials, nano-structural control become indispensable. Because of this circumstance, researcher needs both local precise information and averaged hierarchical information to reveal origin of material performance. In order to do so, utilizing quantum beam, i.e. synchrotron beam, neutron and muon, analysis is important. In this article, examples of utilizing quantum beam analysis for magnetic material research are introduced. In addition, importance of quantifying material data will be mentioned for next generation material research. (author)

  5. Coalbed methane reservoir characterization using magnetic susceptibility

    Science.gov (United States)

    Ivakhnenko, Aleksandr; Makhatova, Meruyert; Kalbekov, Arkhat; Baibussinova, Zhanar; Moldagereyeva, Anel

    2016-04-01

    This research describes a study of the dependence of the magnetic susceptibility (MS) and permeability as a new approach for coalbed methane (CBM) reservoir characterization. Experimental measurements were undertaken in coal cores from Kazakhstan (Karaganda Basin). The well sections containing coal are the area of high interest where regular deposition of sandstone, shale and coal is observed. The MS measurements were made by the core logging sensor with the sensitive area of the probe providing volume magnetic susceptibility values. Permeability has been determined by air permeameter. Both magnetic susceptibility and permeability have been measured at the same points. The obtained values of permeability and magnetic susceptibility exhibit the predicted pattern of deposition of reservoir rocks. Coal reservoirs generally is spaced between shale layers with extremely high MS values and highly low permeability. Sandstone with shale interlayers tends to be a transition area between shale and coal. Such tendency appears within several sections. The experimental results showed a strong correspondence between measured magnetic susceptibility and permeability of coal core samples. Therefore, inverse proportionality between magnetic susceptibility and permeability is observed. Generally, the high values of magnetic susceptibility correspond to low permeability, likewise the low diamagnetic MS values comply with high permeability of production zones. In a point of fact, linear proportionality appears as well due to fractures. In this case, permeability must be recalculated in relation to degree of fracturing. Magnetic susceptibility results could sometimes be affected by small content of ferrimagnetic minerals that resulted in high MS values. However, MS data demonstrated good correlations with permeability. The application of magnetic susceptibility values for coalbed methane reservoir characterization could be a non-destructive and rapid method potentially used in both

  6. Magnetic Stirling cycles - A new application for magnetic materials

    Science.gov (United States)

    Brown, G. V.

    1977-01-01

    There is the prospect of a fundamental new application for magnetic materials as the working substance in thermodynamic cycles. Recuperative cycles which use a rare-earth ferromagnetic material near its Curie point in the field of a superconducting magnet appear feasible for applications from below 20 K to above room temperature. The elements of the cycle, advanced in an earlier paper, are summarized. The basic advantages include high entropy density in the magnetic material, completely reversible processes, convenient control of the entropy by the applied field, the feature that heat transfer is possible during all processes, and the ability of the ideal cycle to attain Carnot efficiency. The mean field theory is used to predict the entropy of a ferromagnet in an applied field and also the isothermal entropy change and isentropic temperature change caused by applying a field. Results are presented for J = 7/2 and g = 2. The results for isentropic temperature change are compared with experimental data on Gd. Coarse mixtures of ferromagnetic materials with different Curie points are proposed to modify the path of the cycle in the T-S diagram in order to improve the efficiency or to increase the specific power.

  7. Advanced transmission electron microscopy on nanostructured magnetic materials

    OpenAIRE

    Campanini, Marco

    2015-01-01

    This doctoral work is focused on the study of nanostructured magnetic materials by advanced transmission electron microscopy (TEM) techniques, with emphasis on Ni2MnGa shape memory alloy thin films and magnetite nanoparticles for biomedical applications. The combination of high-resolution transmission electron microscopy and electron diffraction to characterize morphology and crystalline structure, with Lorentz microscopy and Electron Holography, permits to achieve a deep insight in the s...

  8. Magnetic and electrical control of engineered materials

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Ivan K.; de La Venta Granda, Jose; Wang, Siming; Ramirez, Gabriel; Erekhinskiy, Mikhail; Sharoni, Amos

    2016-08-16

    Methods, systems, and devices are disclosed for controlling the magnetic and electrical properties of materials. In one aspect, a multi-layer structure includes a first layer comprising a ferromagnetic or ferrimagnetic material, and a second layer positioned within the multi-layer structure such that a first surface of the first layer is in direct physical contact with a second surface of the second layer. The second layer includes a material that undergoes structural phase transitions and metal-insulator transitions upon experiencing a change in temperature. One or both of the first and second layers are structured to allow a structural phase change associated with the second layer cause a change magnetic properties of the first layer.

  9. Phonon induced magnetism in ionic materials

    Science.gov (United States)

    Restrepo, Oscar D.; Antolin, Nikolas; Jin, Hyungyu; Heremans, Joseph P.; Windl, Wolfgang

    2014-03-01

    Thermoelectric phenomena in magnetic materials create exciting possibilities in future spin caloritronic devices by manipulating spin information using heat. An accurate understanding of the spin-lattice interactions, i.e. the coupling between magnetic excitations (magnons) and lattice vibrations (phonons), holds the key to unraveling their underlying physics. We report ab initio frozen-phonon calculations of CsI that result in non-zero magnetization when the degeneracy between spin-up and spin-down electronic density of states is lifted for certain phonon displacement patterns. For those, the magnetization as a function of atomic displacement shows a sharp resonance due to the electronic states on the displaced Cs atoms, while the electrons on indium form a continuous background magnetization. We relate this resonance to the generation of a two-level system in the spin-polarized Cs partial density of states as a function of displacement, which we propose to be described by a simple resonant-susceptibility model. Current work extends these investigations to semiconductors such as InSb. ODR and WW are supported by the Center for Emergent Materials, an NSF MRSEC at OSU (Grant DMR-0820414).HJ and JPH are supported by AFOSR MURI Cryogenic Peltier Cooling, Contract #FA9550-10-1-0533.

  10. Synthesis and characterization of biocompatible magnetic glyconanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kekkonen, Viktoria; Lafreniere, Nelson [Department of Chemistry and Biochemistry, Biomolecular Sciences Program, Laurentian University, 935, Ramsey Lake Road, Sudbury, ON, P3E2C6 (Canada); Ebara, Mitsuhiro; Saito, Atsuhiro; Sawa, Yoshiki [Medical Center for Translational Research, Osaka University Hospital, 2-15, Yamada-oka, Suita, Osaka 565-0871 (Japan); Narain, Ravin [Department of Chemistry and Biochemistry, Biomolecular Sciences Program, Laurentian University, 935, Ramsey Lake Road, Sudbury, ON, P3E2C6 (Canada)], E-mail: rnarain@laurentian.ca

    2009-05-15

    Magnetic glyconanoparticles were synthesized via the co-precipitation method. Iron (II) and iron (III) chloride were co-precipitated out of solution by the addition of ammonium hydroxide in an aqueous solution containing carbohydrate stabilizers such as D-gluconic acid, lactobionic acid and Ficoll at 75-80 deg. C. Stable magnetic glyconanoparticles were formed in a simple and direct process. Dynamic light scattering and transmission electron microscopy were used to characterize the surface-coated magnetic nanoparticles. In vitro cell viability studies of the glyconanoparticles were conducted with the mouse fibroblast cell lines. The magnetic glyconanoparticles revealed to be non-toxic at a concentration as high as 0.1 mg/mL.

  11. Synthesis and characterization of biocompatible magnetic glyconanoparticles

    Science.gov (United States)

    Kekkonen, Viktoria; Lafreniere, Nelson; Ebara, Mitsuhiro; Saito, Atsuhiro; Sawa, Yoshiki; Narain, Ravin

    2009-05-01

    Magnetic glyconanoparticles were synthesized via the co-precipitation method. Iron (II) and iron (III) chloride were co-precipitated out of solution by the addition of ammonium hydroxide in an aqueous solution containing carbohydrate stabilizers such as D-gluconic acid, lactobionic acid and Ficoll ® at 75-80 °C. Stable magnetic glyconanoparticles were formed in a simple and direct process. Dynamic light scattering and transmission electron microscopy were used to characterize the surface-coated magnetic nanoparticles. In vitro cell viability studies of the glyconanoparticles were conducted with the mouse fibroblast cell lines. The magnetic glyconanoparticles revealed to be non-toxic at a concentration as high as 0.1 mg/mL.

  12. Magnetic characterization of U/Co multilayers

    International Nuclear Information System (INIS)

    With the aim of expanding the studies on 2D systems containing uranium, U/Co multilayers with layer thickness ranging from 50 to 200 A were recently prepared by dc magnetron sputtering onto glass. The multilayers were characterized by Grazing-Incidence X-Ray Diffraction (GIXRD) and Rutherford Backscattering Spectrometry (RBS). Magnetization measurements performed with a squid magnetometer showed that the multilayers have a ferromagnetic behaviour, with the magnetic signal increasing with the thickness of the layers. The analysis of magnetic anisotropy evidenced an easy magnetic direction in the film plane with large anisotropy fields, which increase with the thickness of the layers and suggests a positive contribution of surface anisotropy to the effective anisotropy Keff. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  13. Synthesis and characterization of biocompatible magnetic glyconanoparticles

    International Nuclear Information System (INIS)

    Magnetic glyconanoparticles were synthesized via the co-precipitation method. Iron (II) and iron (III) chloride were co-precipitated out of solution by the addition of ammonium hydroxide in an aqueous solution containing carbohydrate stabilizers such as D-gluconic acid, lactobionic acid and Ficoll at 75-80 deg. C. Stable magnetic glyconanoparticles were formed in a simple and direct process. Dynamic light scattering and transmission electron microscopy were used to characterize the surface-coated magnetic nanoparticles. In vitro cell viability studies of the glyconanoparticles were conducted with the mouse fibroblast cell lines. The magnetic glyconanoparticles revealed to be non-toxic at a concentration as high as 0.1 mg/mL.

  14. Test of the sample geometry independence of a dynamic hysteretic behavioral model of magnetic materials

    International Nuclear Information System (INIS)

    We propose to use a local dynamic hysteretic model to characterize the dynamic behavior of magnetic materials. This paper shows that a simulation using constant parameters independent of the geometry of the samples give accurate results, even for magnetic materials having very different dynamic behaviors

  15. Optimizing Energy Conversion: Magnetic Nano-materials

    Science.gov (United States)

    McIntyre, Dylan; Dann, Martin; Ilie, Carolina C.

    2015-03-01

    We present herein the work started at SUNY Oswego as a part of a SUNY 4E grant. The SUNY 4E Network of Excellence has awarded SUNY Oswego and collaborators a grant to carry out extensive studies on magnetic nanoparticles. The focus of the study is to develop cost effective rare-earth-free magnetic materials that will enhance energy transmission performance of various electrical devices (solar cells, electric cars, hard drives, etc.). The SUNY Oswego team has started the preliminary work for the project and graduate students from the rest of the SUNY 4E team (UB, Alfred College, Albany) will continue the project. The preliminary work concentrates on analyzing the properties of magnetic nanoparticle candidates, calculating molecular orbitals and band gap, and the fabrication of thin films. SUNY 4E Network of Excellence Grant.

  16. Magnetism in Non-Traditional Materials

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Madhu

    2013-09-17

    We performed a systematic microscopic investigation of two completely dissimilar materials (namely, ZnO and rhombohedral-C{sub 60} polymers) exhibiting ferromagnetism in the presence of defects, and showed that this new phenomena has a common origin and the mechanism responsible can be used as a powerful tool for inducing and tailoring magnetic features in systems which are not magnetic otherwise. Based on our findings we proposed a general recipe for developing ferromagnetism in new materials of great technological interest. Our results support the role of complimentary pairs of defects in inducing magnetism in otherwise non-magnetic materials belonging to two widely differing classes with no apparent correlation between them. In both classes, ferromagnetism is found to be enhanced when the two kinds of defects form structures (pathways) of alternating effective donor and acceptor crystal sites leading to the development of electron charge and spin density like waves. Using ab initio density functional theory calculations we predicted the existence of a new class of carbon cages formed via hybrid connection between planar graphene sheets and carbon nanotubes. The resulting novel structure has the appearance of ?nano-drum? and offers the exciting prospect of integrating useful device properties of both graphene as well as the nanotube into a single unit with tunable electronic properties. Creation of a hexagonal hole in the graphene portion of this structure results in significant magnetic moments for the edge atoms. The structure appears to be capable of sustaining ferrimagnetic state with the assistance of topological defects. The charge and spin distributions obtained in our calculations for the nano-drums are in striking contrast to those in planar graphene nanoribbons with a central hole. In this case, the central hole appears as the complimentary defect to those of the ribbon edges. Similar situation is found in case of the nano-drum in which the

  17. Electromagnetic Scattering and Material Characterization

    CERN Document Server

    Omar, Abbas

    2011-01-01

    Based on the author's more-than 30 years of experience, this first-of-its-kind volume presents a comprehensive and systematic analysis of electromagnetic fields and their scattering by material objects. The book considers all three categories of scattering environments commonly used for material measurements – unbounded regions, waveguides, and cavity resonators. The book covers such essential topics as electromagnetic field propagation, radiation, and scattering, containing mathematically rigorous approaches for the computation of electromagnetic fields and the explanation of their behavior.

  18. Magnetic cassette for radiographic film material

    International Nuclear Information System (INIS)

    A radiographic film cassette having a plurality of magnet components integral with the cassette holder for adhering the cassette to ferrous material in X-raying for defects in welds or fissures in shipyards, pipe lines, or the like. What is provided is a substantially flexible cassette envelope comprising first and second layers of radiographic intensifying screens with a sheet of radiographic film positioned therebetween. The cassette would be a cassette envelope constructed of waterproof fabric or other suitable material providing a light-free environment, and having the ability to flex around the curvature of the surface of a pipe or the like to be x-rayed. There is further provided a plurality of magnet components, preferably situated in each corner of the cassette envelope and flexibly attached thereto for overall adherence of the envelope to the surface of the pipe or the like to be x-rayed during the process

  19. Magnetic Characterization of Sulphide Ores: Examples From Sweden

    OpenAIRE

    Jirestig, J.; Forssberg, E.

    1992-01-01

    Diagrams of accumulativemagnetic susceptibility distribution are used to evaluate the suitability of four sulphide ores for magnetic methods of beneficiation. The investigated materials are Garpenberg, Aitik and Kedtrask. The samples were divided into susceptibility classes each of which was characterized by its mineral content. The results are presented as diagrams showing mineral appearance in the whole susceptibility range of the ore. The obtained accumulative susceptibility diagrams can b...

  20. High-frequency response of nanostructured magnetic materials

    International Nuclear Information System (INIS)

    This paper reports a brief overview on recent developments regarding the high-frequency response in the GHz range of nanostructured magnetic materials. Emphasis is placed on the linear regime in the frequency domain characterized by the dynamic susceptibility spectrum. Some modeling tools and experimental probes allowing determination of the dynamic susceptibility spectrum are first rapidly reviewed and their respective advantages and disadvantages are discussed. Next, some illustrative examples of the high-frequency response of nanopatterned materials based on recent works are presented. The role played by the shape of the element on the characteristics of excitation spectrum is underlined. Lastly, some prospects are proposed and promising trends are highlighted.

  1. Electrochromic & magnetic properties of electrode materials for lithium ion batteries

    Science.gov (United States)

    Zheng-Fei, Guo; Kun, Pan; Xue-Jin, Wang

    2016-01-01

    Progress in electrochromic lithium ion batteries (LIBs) is reviewed, highlighting advances and possible research directions. Methods for using the LIB electrode materials’ magnetic properties are also described, using several examples. Li4Ti5O12 (LTO) film is discussed as an electrochromic material and insertion compound. The opto-electrical properties of the LTO film have been characterized by electrical measurements and UV-Vis spectra. A prototype bi-functional electrochromic LIB, incorporating LTO as both electrochromic layer and anode, has also been characterized by charge- discharge measurements and UV-Vis transmittance. The results show that the bi-functional electrochromic LIB prototype works well. Magnetic measurement has proven to be a powerful tool to evaluate the quality of electrode materials. We introduce briefly the magnetism of solids in general, and then discuss the magnetic characteristics of layered oxides, spinel oxides, olivine phosphate LiFePO4, and Nasicon-type Li3Fe2(PO4)3. We also discuss what kind of impurities can be detected, which will guide us to fabricate high quality films and high performance devices. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA034201) and the Chinese Universities Scientific Fund (Grant No. 2015LX002).

  2. Structural and magnetic characterization of martensitic Maraging-350 steel

    International Nuclear Information System (INIS)

    A solubilized Maraging-350 steel used in the nuclear industry, as received from the manufacturer, was finely characterized by X-ray diffraction (Rietveld refinement), Mössbauer spectroscopy and magnetization techniques. For these characterizations, samples were prepared with exceptional care regarding any possible modification of the physical properties of the steel due to mechanical work done on the original piece during specimen preparation. The results showed that the steel is martensitic, although evidence of a crystallographic distortion from the cubic symmetry usually attributed to the martensite was found. It was also revealed that the atomic configurations of the iron nearest neighbors may be assembled in three groups, according to the hyperfine magnetic field at the iron sites. Magnetic minor loops displayed a soft magnetic material with the coercive field, residual induction and loop area obtained as a function of the maximum applied field in the loop obeying peculiar behaviors. The measured properties represent key information for a suitable control for the aging of Maraging-350 and, consequently, for the design of ultracentrifuges used in the isotope enrichment of nuclear fuel. - Highlights: • We report a fine characterization of the martensitic Maraging-350 steel. • A crystallographic distortion from the cubic symmetry usually attributed to the martensite phase was found. • The atomic configurations of the iron nearest neighbors may be assembled in three groups. • Magnetic minor loops displayed a soft magnetic material with extrinsic parameters obeying peculiar behaviors. • The measured properties represent key information for a suitable control for the aging of Maraging-350 steel

  3. Structural and magnetic characterization of martensitic Maraging-350 steel

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, G.C.S. [Universidade Estadual de Maringá, Departamento de Física, Av. Colombo, 5790, 87.020-900, PR (Brazil); Sarvezuk, P.W.C. [Universidade Tecnológica Federal do Paraná, Campo Mourão, PR (Brazil); Biondo, V. [Universidade Estadual de Maringá, Departamento de Física, Av. Colombo, 5790, 87.020-900, PR (Brazil); Blanco, M.C. [Universidad Nacional de Córdoba (Argentina); Nunes, M.V.S. [Universidade Estadual de Maringá, Departamento de Física, Av. Colombo, 5790, 87.020-900, PR (Brazil); Andrade, A.M.H. de [Universidade Federal do Rio Grande do Sul, Instituto de Física, RS (Brazil); Paesano, A., E-mail: paesano@wnet.com.br [Universidade Estadual de Maringá, Departamento de Física, Av. Colombo, 5790, 87.020-900, PR (Brazil)

    2015-10-15

    A solubilized Maraging-350 steel used in the nuclear industry, as received from the manufacturer, was finely characterized by X-ray diffraction (Rietveld refinement), Mössbauer spectroscopy and magnetization techniques. For these characterizations, samples were prepared with exceptional care regarding any possible modification of the physical properties of the steel due to mechanical work done on the original piece during specimen preparation. The results showed that the steel is martensitic, although evidence of a crystallographic distortion from the cubic symmetry usually attributed to the martensite was found. It was also revealed that the atomic configurations of the iron nearest neighbors may be assembled in three groups, according to the hyperfine magnetic field at the iron sites. Magnetic minor loops displayed a soft magnetic material with the coercive field, residual induction and loop area obtained as a function of the maximum applied field in the loop obeying peculiar behaviors. The measured properties represent key information for a suitable control for the aging of Maraging-350 and, consequently, for the design of ultracentrifuges used in the isotope enrichment of nuclear fuel. - Highlights: • We report a fine characterization of the martensitic Maraging-350 steel. • A crystallographic distortion from the cubic symmetry usually attributed to the martensite phase was found. • The atomic configurations of the iron nearest neighbors may be assembled in three groups. • Magnetic minor loops displayed a soft magnetic material with extrinsic parameters obeying peculiar behaviors. • The measured properties represent key information for a suitable control for the aging of Maraging-350 steel.

  4. Analytical nondestructive evaluation for materials characterization

    International Nuclear Information System (INIS)

    Science and technology of nondestructive testing and evaluation has contributed immensely to the safety and productivity of industrial plants. In recent years, nondestructive evaluation (NDE) has emerged as a frontline research area of equal if not greater technological relevance, for materials characterization as well. A comprehensive range of techniques from qualitative nondestructive testing for quality control of engineering products and materials to quantitative NDE for materials characterization is being used by the engineering industry and materials researchers, for better understanding of the manufacturing practices and materials behaviour. Quantitative NDE is considered essential for ensuring fitness for purpose at the start of the life in case the component has been designed using fracture mechanics parameters. Quantitative NDE is also vital for assessing degradation of material during service. Moreover, quantitative NDE enables characterization of dynamics of certain phenomenon (not achievable by destructive test methodologies) leading to better understanding of the performance of materials in relation to unavoidable defects in the materials. As the next logical step, the need for an analytical approach to NDE is felt. The need and motivation for such an approach is addressed and the means to achieve this objective are identified. It is argued that analytical NDE is essential to meet the challenges of characterization, intelligent processing of materials and life prediction of components and plants. These requirements are of significant importance in the context of recent developments in materials engineering, and for enhancing the competitive advantage of Indian engineering industry in the international market. (author). 9 refs., 3 figs

  5. The magnetic resonance force microscope: A new microscopic probe of magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1997-08-06

    The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

  6. High gradient magnetic separation for powder material processing

    OpenAIRE

    Idziaszek-Gonzalez, Alicja; Kozlowski, Waldemar

    2013-01-01

    High gradient magnetic separators are widely used in both research and industry. The aim of the work is the analysis of magnetic separation for powder material processing. The paper presents the simulations of magnetic field for magnetic separators with various filter shapes. Finite Element Analysis has been used to get the magnetic field over the studied separator grid.

  7. Purpose of the Materials Characterization Center

    International Nuclear Information System (INIS)

    The Materials Characterization Center (MCC) at the Pacific Northwest Laboratory is the experimental arm of the Materials Characterization Organization (MCO), which was established by the US Department of Energy (DOE) in FY 1980 to ensure high quality characterization and qualification of waste package materials essential to the reliable performance of DOE nuclear waste management programs. The MCC is responsibe for publishing key test methods and data in the Nuclear Waste Materials Handbook (DOE/TIC-11400) after the methods and data have been reviewed and approved by the Materials Review Board (MRB), which is the other major operating arm of the MCO. The MCC is carrying out its responsibilities in several ways. It sponsors a continuing series of workshops that address materials characterization test method issues. It supplies well-characterized reference and testing materials for use by the DOE nuclear waste management programs. It develops generic tests methods and supports the repository waste package projects in developing selected site-specific test methods and performing confirmatory testing of these methods. When these test methods are approved by the MRB they constitute the formal tests to be used by laboratories to test and qualify materials, evaluate waste package components, and assure compliance with standards and/or specifications for the final product

  8. Towards an integrated materials characterization toolbox

    DEFF Research Database (Denmark)

    Robertson, Ian M.; Schuh, Christopher A.; Vetrano, John S.;

    2011-01-01

    The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight to...... reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors' viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future...... the state-of-the-art in characterization and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis...

  9. Characterization of nanoparticles as candidate reference materials

    International Nuclear Information System (INIS)

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  10. Characterization of nanoparticles as candidate reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Martins Ferreira, E.H.; Robertis, E. de; Landi, S.M.; Gouvea, C.P.; Archanjo, B.S.; Almeida, C.A.; Araujo, J.R. de; Kuznetsov, O.; Achete, C.A., E-mail: smlandi@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    We report the characterization of three different nanoparticles (silica, silver and multi-walled carbon nanotubes) as candidate reference material. We focus our analysis on the size distribution of those particles as measured by different microscopy techniques. (author)

  11. Characteristics of anthropogenic magnetic materials in roadside dusts in Seoul, Korea using thermo-magnetic behaviors and electron microscope observations

    Science.gov (United States)

    Kim, W.; Doh, S.; Park, Y.

    2006-12-01

    It has been previously reported that magnetic concentration parameter (e.g., magnetic susceptibility) has a close affinity with heavy metal concentration in roadside dust of the Seoul metropolitan area. Magnetic concentration and magnetic particle size show systematic seasonal fluctuations (high and large during winter; low and small in summer) because of seasonal influx variation of anthropogenic magnetic materials. These observations suggest that magnetic parameters could be utilized as a proxy method of assessing heavy metal pollution in urban areas. In order to characterize anthropogenic magnetic materials and to find their potential sources, magnetic extracts from roadside dusts of Seoul metropolitan area were subject to SEM observation, elemental analysis (EDS), and thermo-magnetic experiments. Magnetic materials from vehicle emission and abraded brake lining were also observed for the comparison. The magnetic particles can be classified based on the morphology and elemental composition of the particles. Magnetic spherules are the most frequently observed type of particle throughout the study area. These particles are often associated with the elemental C and Al-Ca-Na-Si materials, and are believed to be the product of fossil fuel combustions in power plants, industries, and domestic heating systems. Aggregates of iron-oxides and Fe-C-S materials are probably originated from vehicle emission, while aggregates of pure Fe and Al-Ca-Fe-K-Mg-Si materials appear to be derived from abrasion of motor vehicle brake system. These aggregates are frequently observed in industrial sections of the city as well as areas of heavy traffic. Angular magnetic particles accompanied by silicates are only observed in park area and probably formed by natural process such as pedogenesis or weathering. Thermo-magnetic experiments indicate that the major magnetic phase in the studied samples is magnetite. Two distinctive behaviors observed are the presence of low Curie temperature

  12. Purpose of the Materials Characterization Center

    International Nuclear Information System (INIS)

    The Materials Characterization Center (MCC) at the Pacific Northwest Laboratory is the experimental arm of the Materials Characterization Organization (MCO), which was established by the US Department of Energy (DOE) in FY 1980 to ensure high quality characterization and qualification of waste package materials essential to the reliable performance of DOE nuclear waste management programs. MCC is responsible for publishing key test methods and data in the Nuclear Waste Materials Handbook (DOE/TIC-11400). It sponsors a continuing series of workshops that address materials characterization test method issues. It supplies well-characterized reference and testing materials for use by the DOE nuclear waste management programs. It develops generic test methods and supports the repository waste package projects in developing selected site-specific test methods and performing confirmatory testing of these methods. When these test methods are approved by the MRB they constitute the formal tests to be used by laboratories to test and qualify materials, evaluate waste package components, and assure compliance with standards and/or specifications for the final product

  13. Magnetic stirling cycles: A new application for magnetic materials

    Science.gov (United States)

    Brown, G. V.

    1977-01-01

    The elements of the cycle are summarized. The basic advantages include high entropy density in the magnetic material, completely reversible processes, convenient control of the entropy by the applied field, the feature that heat transfer is possible during all processes, and the ability of the ideal cycle to attain Carnot efficiency. The mean field theory is used to predict the entropy of a ferromagnet in an applied field and also the isothermal entropy change and isentropic temperature change caused by applying a field. The results for isentropic temperature change are compared with experimental data on Gd. Coarse mixtures of ferromagnetic materials with different Curie points are proposed to modify the path of the cycle in the T-S diagram in order to improve the efficiency or to increase the specific power.

  14. Nanocrystalline and Nanocomposite Magnetic Materials and Their Applications

    Institute of Scientific and Technical Information of China (English)

    Robert D Shull

    2007-01-01

    Nanocrystalline materials can possess bulk properties quite different from those commonly associated with conventional large-grained materials. Nanocomposites, a subset of nanocrystalline materials, in addition have been found to possess magnetic properties which are similar to, but different from, the properties of the individual constituents. New magnetic phenomena, unusual property combinations, and both enhanced and diminished magnetic property values are just some of the changes observed in magnetic nanocomposites from conventional magnetic materials. Here, a description will be presented of some of the exciting new properties discovered in nanomaterials and the magnetic applications envisioned for them.

  15. Reference and testing materials available from the Materials Characterization Center

    International Nuclear Information System (INIS)

    A major responsibility of the Materials Characterization Center (MCC) is to acquire and distribute reference and testing materials endorsed by DOE, for use in research and development in nuclear waste management. MCC standard materials provide a common basis for data obtained in waste repository development work, thereby assisting in developing a defensible database of known accuracy and precision. Homogeneity of standard materials is of particular importance. MCC emphasizes homogeneity of composition and physical characteristics of the standard materials, using statistical methods in sampling procedures and evaluation of analytical data. Two classifications of standard materials are available from the MCC. Approved Reference Materials (ARMs) are intended as standard reference and calibration materials [similar to the SRMs of the US National Bureau of Standards (NBS)], for field calibration of MCC standard test methods. Each ARM is characterized by MCC and other laboratories such as NBS to a high level of accuracy and precision. Approved Testing Materials (ATMs) are used as common testing materials, representing specific formulations of typical waste forms. Most ATMs are radioactive materials, for which characterization has been conducted on shielded analytical instruments at PNL. More than ten different ATMs (borosilicate glass and spent fuel) are in the MCC inventory. These materials are available without charged, in reasonable amounts, to DOE programs. Other users pay pro-rated production costs. The materials normally are supplied in the form in which they were produced, e.g., glass as-cast bars. In some cases the MCC can supply special specimen forms, e.g., crushed powders or shaped monoliths

  16. Magnetic Resonance Studies of Energy Storage Materials

    Science.gov (United States)

    Vazquez Reina, Rafael

    In today's society there is high demand to have access to energy for portable devices in different forms. Capacitors with high performance in small package to achieve high charge/discharge rates, and batteries with their ability to store electricity and make energy mobile are part of this demand. The types of internal dielectric material strongly affect the characteristics of a capacitor, and its applications. In a battery, the choice of the electrolyte plays an important role in the Solid Electrolyte Interphase (SEI) formation, and the cathode material for high output voltage. Electron Paramagnetic Resonance (EPR) and Nuclear Magnetic Resonance (NMR) spectroscopy are research techniques that exploit the magnetic properties of the electron and certain atomic nuclei to determine physical and chemical properties of the atoms or molecules in which they are contained. Both EPR and NMR spectroscopy technique can yield meaningful structural and dynamic information. Three different projects are discussed in this dissertation. First, High energy density capacitors where EPR measurements described herein provide an insight into structural and chemical differences in the dielectric material of a capacitor. Next, as the second project, Electrolyte solutions where an oxygen-17 NMR study has been employed to assess the degree of preferential solvation of Li+ ions in binary mixtures of EC (ethylene carbonate) and DMC (dimethyl carbonate) containing LiPF6 (lithium hexafluo-rophosphate) which may be ultimately related to the SEI formation mechanism. The third project was to study Bismuth fluoride as cathode material for rechargeable batteries. The objective was to study 19F and 7Li MAS NMR of some nanocomposite cathode materials as a conversion reaction occurring during lithiation and delithation of the BiF3/C nanocomposite.

  17. Physical characterization methods for supplementary cementitious materials

    OpenAIRE

    Arvaniti, Eleni; Juenger, Maria; Bernal, Susan; Duchesne, Josée; Courard, Luc; Leroy, Sophie; Provis, John; Klemm, Agnieska; De Belie, Nele

    2015-01-01

    The main supplementary cementitious materials (SCMs) that are used today are industrial by-products. In most cases the quality of these materials cannot be controlled during their production, resulting in materials with varied characteristics. The adequate physical characterization of SCMs is important to better predict their performance and optimize their use in concretes production. There are standardized methods used to determine the particle characteristics for Portland cements that are u...

  18. Magnetic Performance of a Nanocomposite Permanent Material

    Institute of Scientific and Technical Information of China (English)

    LIU Min; HAN Guang-Bing; GAO Ru-Wei

    2011-01-01

    @@ We build a sandwiched structure model in which the intergranular phase(IP) is homogeneously distributed between soft and hard magnetic grains, and gives a continuously anisotropic expression of the coupling part under the assumption that the IP weakens the intergrain exchange-coupling interaction.Based on the idea that the hardening mechanism is of the pinning type, we calculate the effect of the IP's thickness d and its anisotropy constant K1(0) on the intrinsic coercivity of a nanocomposite permanent material.The calculated results indicate that the domain wall goes twice through irreversible domain wall displacement during the process of moving from soft to hard magnetic grains, and the intrinsic coercivity increases with increasing d, but decreases with increasing K1(0).When d and K1(0) take 2nm and 0.7Kh, respectively, with Kh being the anisotropy constant in the inner part of the hard magnetic grain, the calculated intrinsic coercivity is in good agreement with the experimental data.

  19. Magnetic filtration process, magnetic filtering material, and methods of forming magnetic filtering material

    Science.gov (United States)

    Taboada-Serrano, Patricia; Tsouris, Constantino; Contescu, Cristian I; McFarlane, Joanna

    2013-10-08

    The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically responsive activated carbon typically includes providing activated carbon in a solution containing ions of ferrite forming elements, wherein at least one of the ferrite forming elements has an oxidation state of +3 and at least a second of the ferrite forming elements has an oxidation state of +2, and increasing pH of the solution to precipitate particles of ferrite that bond to the activated carbon, wherein the activated carbon having the ferrite particles bonded thereto have a positive magnetic susceptibility. The present invention also provides a method of filtering waste water using magnetic activated carbon.

  20. Investigation of diluted magnetic semiconductor and nano magnetic material by ion beam technology

    International Nuclear Information System (INIS)

    In this paper, we focus on constitution, magnetism modification and characterization of GaN-based materials using ion beam technology and formation of the nano structure by implanting Mn+ or Co+ ion of different doses into the film samples. SQUID and AGM were used to measure the magnetic properties, such as coercivity and saturation magnetization, for the samples before and after annealing, M-H and M-T curves showed ferromagnetism in the films at both low temperature and room temperature. RBS/C, PIXE and XRD were used to analyze the microstructure, content of doping transition metal and damage. The nano-cluster of ferromagnetism particle was observed under HRTEM. (authors)

  1. Nondestructive materials characterization with applications to aerospace materials

    CERN Document Server

    Nagy, Peter; Rokhlin, Stanislav

    2004-01-01

    With an emphasis on aircraft materials, this book describes techniques for the material characterization to detect and quantify degradation processes such as corrosion and fatigue. It introduces readers to these techniques based on x-ray, ultrasonic, optical and thermal principles and demonstrates the potential of the techniques for a wide variety of applications concerning aircraft materials, especially aluminum and titanium alloys. The advantages and disadvantages of various techniques are evaluated. An introductory chapter describes the typical degradation mechanisms that must be considered and the microstructure features that have to be detected by NDE methods. Finally, some approaches for making lifetime predictions are discussed. It is suitable as a textbook in special training courses in advanced NDE and aircraft materials characterization.

  2. Micro magnetic investigation of the relaxation process in hard magnetic materials

    International Nuclear Information System (INIS)

    The relaxation of several micro magnetic model systems has been studied . Our results show that similarly to hysteresis, relaxation proceeds through the nucleation and propagation of domain wall-like structures involving a number of magnetic moments which is linked to the exchange correlation length of the material, the probability of magnetization reversal of simple homogeneous system is characterized by the occurrence of a 'waiting time'during which the macroscopic state of the system evolves very slowly and the time required to get probability one of magnetization reversal is, different from the predictions of the Arrhenius kinetics finite. Despite these departures from the predictions of the classic two-level description of the relaxation processes, the evolution at constant field and temperature of the magnetization of systems with distributed properties can be represented, in limited time intervals, by logarithmic laws similar to those commonly used when discussing experimental data. We analyze the relationships between the parameters describing these logarithmic laws and some characteristics of the magnetic moment configurations observed during relaxation. (author)

  3. Characterization of DWPF recycle condensate materials

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Adamson, D. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-04-01

    A Defense Waste Processing Facility (DWPF) Recycle Condensate Tank (RCT) sample was delivered to the Savannah River National Laboratory (SRNL) for characterization with particular interest in the concentration of I-129, U-233, U-235, total U, and total Pu. Since a portion of Salt Batch 8 will contain DWPF recycle materials, the concentration of I-129 is important to understand for salt batch planning purposes. The chemical and physical characterizations are also needed as input to the interpretation of future work aimed at determining the propensity of the RCT material to foam, and methods to remediate any foaming potential. According to DWPF the Tank Farm 2H evaporator has experienced foaming while processing DWPF recycle materials. The characterization work on the RCT samples has been completed and is reported here.

  4. Qualification protocol for hysteresis model of magnetic materials in static and dynamic modes. Application in design software

    OpenAIRE

    Do, Thaï-Phuong; Sixdenier, Fabien; Morel, Laurent; Morin, Eric; Gerbaud, Laurent; Wurtz, Frédéric

    2009-01-01

    The magnetic material modeling plays an important role in the electromagnetism simulation, especially the losses computation. However, it is a complex problem because of the material hysteretic characteristics. This paper proposes a characterization step to be applied in soft magnetic materials modeling that allow modeling them in both static and dynamic functio

  5. Tests on irradiated magnet insulator materials

    International Nuclear Information System (INIS)

    Fusion reactor coils, located in areas where they will be only partially shielded, must be fabricated from materials which are as resistant to radiation as possible. They will probably incorporate resistive conductors with either water or cryogenic cooling. Inorganic insulators have been recommended for these situations, but the possibility exists that some organic insulators may be usable as well. Five insulator materials were investigated in this work, two containing E-glass cloth (contains B2O2) and three containing S-glass cloth (boron free). Disks of these materials were irradiated in two capsules in the Advanced Test Reactor at 325 K to a gamma dose of over 3.2 x 109 Gy, a fast neutron fluence of 3.5 x 1023 n/m2 (E > 1.0 MeV), and a total neutron fluence of 3.5 x 1024 n/m2 for the lower fluence capsule. Following irradiation, compressive fatigue tests were made at room temperature on all five candidate materials. No failures were observed for the three insulators containing S-glass when cycled to a maximum stress of 345 MPa (50 ksi) for over 1.5 x 105 cycles. In comparison, the G-11CR failed in a few cycles at the lowest stress level applied and the G-10 failed after a number of cycles which varied according to the applied stress level. Electrical resistivity measurements were also made; G-10 showed the largest decrease, and the materials containing S-glass showed the smallest decrease in resistivity due to irradiation. These insulators containing S-glass have given encouraging results for fusion magnet applications and should receive further consideration. (orig.)

  6. Evaluation of airborne thermal, magnetic, and electromagnetic characterization technologies

    International Nuclear Information System (INIS)

    The identification of Buried Structures (IBS) or Aerial Surveillance Project was initiated by the US Department of Energy (DOE) Office of Technology Development to demonstrate airborne methods for locating and identifying buried waste and ordnance at the Idaho National Engineering Laboratory (INEL). Two technologies were demonstrated: (a) a thermal infrared imaging system built by Martin Marietta Missile Systems and (b) a magnetic and electromagnetic (EM) geophysical surveying system operated by EBASCO Environmental. The thermal system detects small differences in ground temperature caused by uneven heating and cooling of the ground by the sun. Waste materials on the ground can be detected when the temperature of the waste is different than the background temperature. The geophysical system uses conventional magnetic and EM sensors. These sensors detect disturbances caused by magnetic or conductive waste and naturally occurring magnetic or conductive features of subsurface soils and rock. Both systems are deployed by helicopter. Data were collected at four INEL sites. Tests at the Naval Ordnance Disposal Area (NODA) were made to evaluate capabilities for detecting ordnance on the ground surface. Tests at the Cold Simulated Waste Demonstration Pit were made to evaluate capabilities for detecting buried waste at a controlled site, where the location and depth of buried materials are known. Tests at the Subsurface Disposal Area and Stationary Low-Power Reactor-1 burial area were made to evaluate capabilities for characterizing hazardous waste at sites that are typical of DOE buried waste sites nationwide

  7. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology; Sintese e caracterizacao de nanoparticulas magneticas de ferrita de cobalto recobertas por 3-aminopropiltrietoxissilano para uso como material hibrido em nanotecnologia

    Energy Technology Data Exchange (ETDEWEB)

    Camilo, Ruth Luqueze

    2006-07-01

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H{sub 2}O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  8. OBTAINING HYSTERESIS LOOPS AT LOW FREQUENCY FOR CHARACTERIZATION OF MATERIALS TO BE USED IN BIOMEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Atika Arshad

    2015-05-01

    Full Text Available The promising development of magnetic sensors in biomedical field demands an appropriate level of understanding of the magnetic properties of the materials used in their fabrication. To date only few of the types of magnetic materials are encountered where their magnetic properties, characterization techniques and magnetization behavior are yet to be explored more suitably in the light of their applications. This research work studies the characterization of materials by using a cost effective and simple circuit consisting of inductive transducer and an OP-AMP as a voltage integrator. In this approach the circuit was simulated using PSPICE and experiments have been conducted to achieve the desired results. The simulation and experimental results are obtained for three test materials namely iron, steel and plastic. The novelty lies in applying the simple circuit for material testing and characterization via obtaining simulation results and validating these results through experiment. The magnetic properties in low external magnetic field are studied with materials under test. The magnetization effect of a magneto-inductive sensor is detected in low frequency range for different magnetic core materials. The results have shown magnetization behaviour of magnetic materials due to the variation of permeability and magnetism. The resulted hysteresis loops appeared to have different shapes for different materials. The magnetic hysteresis loop found for iron core demonstrated a bigger coercive force and larger reversals of magnetism than these of steel core, thus obtaining its magnetic saturation at a larger magnetic field strength. The shape of the hysteresis loop itself is found to be varying upon the nature of the material in use. The resulted magnetization behaviors of the materials proved their possible applicability for use in sensing devices. The key concern of this work is found upon selecting the appropriate magnetic materials at the desired

  9. In situ observation of magnetic orientation process of feeble magnetic materials under high magnetic fields

    Directory of Open Access Journals (Sweden)

    Noriyuki Hirota et al

    2008-01-01

    Full Text Available An in situ microscopic observation of the magnetic orientation process of feeble magnetic fibers was carried out under high magnetic fields of up to 10 T using a scanning laser microscope. In the experiment, carbon fibers and needle-like titania fibers with a length of 1 to 20 μm were used. The fibers were observed to gradually orient their axes parallel to the direction of the magnetic field. The orientation behavior of the sample fibers was evaluated on the basis of the measured duration required for a certain angular variation. As predicted from the theoretical consideration, it was confirmed that the duration required for a certain angular variation normalized by the viscosity of the fluid is described as a function of the fiber length. The results obtained here appear useful for the consideration of the magnetic orientation of materials suspended in a static fluid.

  10. An analytical model for the effect in magnetic materials

    OpenAIRE

    Daniel, L.; Hubert, O.

    2009-01-01

    Abstract The effect is often presented as the dependency of the Young's modulus of a material on its state of magnetization. Nevertheless, the elastic properties of a magnetic material do not depend on the magnetization state. Actually, the sensitivity of the magnetostriction strain to the application of a stress explains the effect. According to this statement, a semi-analytical model for the effect is proposed, in which magnetization rotation is not considered. An experimental...

  11. A study of the hard magnetic properties in different hard magnetic materials

    International Nuclear Information System (INIS)

    The magnetic properties of several hard magnetic materials have been investigated to determine any trends in their magnetic characteristics. The materials studied were Nd15Fe77B8, SmCo5, Sm2 (Co,Fe,Cu,Zr)17, strontium ferrite magnets and single domain particles of Ba-ferrite and Cu-Mn-Al. The initial magnetization curves, field dependence of coercivity and remanence curves were measured

  12. Magnetic materials, varistors and superconductors: Applications and development trends

    International Nuclear Information System (INIS)

    This volume of proceedings deals with the following four main topics: 1. soft magnetic materials (for example magnetic properties or reduction of the remagnetization losses of electric sheets; new magnetic materials for transformers or chokes); 2. hard magnetic materials (permanent magnets); 3. varistors (production, properties, range of application) and 4. range of applications of superconductors (high-temperature superconduction transformers; interconnection through a current-limiting choke with a high-temperature superconduction core; possible effects of high-temperature superconduction on inductive energy accumulators). 8 of the 22 contributions were separately recorded for the data base ENERGY. (MM)

  13. Nondestructive characterization of advanced composite materials

    International Nuclear Information System (INIS)

    A comprehensive review of nondestructive characterization (NDC) techniques and their application to metal-matrix, polymer-matrix and ceramic-matrix composites is presented. Particular attention is given to the identification of critical materials properties and defects in these advanced composites. NDC is required: (i) to detect discrete defects, such as delaminations and cracking, and (ii) to measure distributed material properties, such as density, resistivity and elastic constants. Ultrasonic and eddy-current characterization are described in detail, along with new NDC results obtained at the Aeronautical and Maritime Research Laboratory. These include a method for the determination of fibre volume fraction in continuous fibre reinforced metal-matrix composites using eddy-current NDC, and the use of eddy-current methods to complement ultrasonic testing for characterization of impact damage in graphite-epoxy laminates. Future problem areas and possible solutions in NDC of advanced composites are also discussed. 90 refs., 1 tab., 6 figs

  14. Study of the influence of simultaneous variation of magnetic material microstructural features on domain wall dynamics

    International Nuclear Information System (INIS)

    The magnetic Barkhausen noise (MBN) is a phenomenon sensitive to several kinds of magnetic material microstructure changes, as well as to variations in material plastic deformation and stress. This fact stimulates the development of MBN-based non-destructive testing (NDT) techniques for analyzing magnetic materials, being the proposition of such a method, the main objective of the present study. The behavior of the MBN signal envelope, under simultaneous variations of carbon content and plastic deformation, is explained by the domain wall dynamics. Additionally, a non-destructive parameter for the characterization of each of these factors is proposed and validated through the experimental results.

  15. Electron backscatter diffraction in materials characterization

    Directory of Open Access Journals (Sweden)

    Dejan Stojakovic

    2012-03-01

    Full Text Available Electron Back-Scatter Diffraction (EBSD is a powerful technique that captures electron diffraction patterns from crystals, constituents of material. Captured patterns can then be used to determine grain morphology, crystallographic orientation and chemistry of present phases, which provide complete characterization of microstructure and strong correlation to both properties and performance of materials. Key milestones related to technological developments of EBSD technique have been outlined along with possible applications using modern EBSD system. Principles of crystal diffraction with description of crystallographic orientation, orientation determination and phase identification have been described. Image quality, resolution and speed, and system calibration have also been discussed. Sample preparation methods were reviewed and EBSD application in conjunction with other characterization techniques on a variety of materials has been presented for several case studies. In summary, an outlook for EBSD technique was provided.

  16. Composite particles formed by complexation of poly(methacrylic acid) - stabilized magnetic fluid with chitosan: Magnetic material for bioapplications.

    Science.gov (United States)

    Safarik, Ivo; Stepanek, Miroslav; Uchman, Mariusz; Slouf, Miroslav; Baldikova, Eva; Nydlova, Leona; Pospiskova, Kristyna; Safarikova, Mirka

    2016-10-01

    A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates. PMID:27287146

  17. Chitosan magnetic microspheres for technological applications: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Podzus, P.E. [Grupo de Aplicaciones de Materiales Biocompatibles, Departamento de Quimica, Facultad de Ingenieria, Universidad de Buenos Aires. Paseo Colon 850, C1063ACV Buenos Aires (Argentina); LAFMACEL, Departamento de Quimica, Facultad de Ingenieria, Universidad de Buenos Aires. Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Daraio, M.E., E-mail: medit@fi.uba.a [Grupo de Aplicaciones de Materiales Biocompatibles, Departamento de Quimica, Facultad de Ingenieria, Universidad de Buenos Aires. Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Jacobo, S.E., E-mail: sjacobo@fi.uba.a [LAFMACEL, Departamento de Quimica, Facultad de Ingenieria, Universidad de Buenos Aires. Paseo Colon 850, C1063ACV Buenos Aires (Argentina)

    2009-10-01

    One of the major applications of chitosan and its many derivatives are based on its ability to bind strongly heavy and toxic metal ions. In this study chitosan magnetic microspheres have been synthesized. Acetic acid (1%w/v) solution was used as solvent for the chitosan polymer solution (2%w/v) where magnetite nanoparticles were suspended in order to obtain a stable ferrofluid. Glutaraldehyde was used as cross-linker. The magnetic characteristic of these materials allows an easy removal after use if is necessary. The morphological characterization of the microspheres shows that they can be produced in the size range 800-1100 mum. The adsorption of Cu(II) onto chitosan-magnetite nanoparticles was studied in batch system. A second-order kinetic model was used to fit the kinetic data, leading to an equilibrium adsorption capacity of 19 mg Cu/g chitosan.

  18. Chitosan magnetic microspheres for technological applications: Preparation and characterization

    International Nuclear Information System (INIS)

    One of the major applications of chitosan and its many derivatives are based on its ability to bind strongly heavy and toxic metal ions. In this study chitosan magnetic microspheres have been synthesized. Acetic acid (1%w/v) solution was used as solvent for the chitosan polymer solution (2%w/v) where magnetite nanoparticles were suspended in order to obtain a stable ferrofluid. Glutaraldehyde was used as cross-linker. The magnetic characteristic of these materials allows an easy removal after use if is necessary. The morphological characterization of the microspheres shows that they can be produced in the size range 800-1100 μm. The adsorption of Cu(II) onto chitosan-magnetite nanoparticles was studied in batch system. A second-order kinetic model was used to fit the kinetic data, leading to an equilibrium adsorption capacity of 19 mg Cu/g chitosan.

  19. Magnetic and Electrical Characteristics of Cobalt-Based Amorphous Materials and Comparison to a Permalloy Type Polycrystalline Material

    Science.gov (United States)

    Wieserman, William R.; Schwarze, Gene E.; Niedra, Janis M.

    2005-01-01

    Magnetic component designers are always looking for improved soft magnetic core materials to increase the efficiency, temperature rating and power density of transformers, motors, generators and alternators, and energy density of inductors. In this paper, we report on the experimental investigation of commercially available cobalt-based amorphous alloys which, in their processing, were subjected to two different types of magnetic field anneals: A longitudinal magnetic field anneal or a transverse magnetic field anneal. The longitudinal field annealed material investigated was Metglas 2714A. The electrical and magnetic characteristics of this material were investigated over the frequency range of 1 to 200 kHz and temperature range of 23 to 150 C for both sine and square wave voltage excitation. The specific core loss was lower for the square than the sine wave voltage excitation for the same maximum flux density, frequency and temperature. The transverse magnetic field annealed core materials include Metglas 2714AF and Vacuumschmelze 6025F. These two materials were experimentally characterized over the frequency range of 10 to 200 kHz for sine wave voltage excitation and 23 C only. A comparison of the 2174A to 2714AF found that 2714AF always had lower specific core loss than 2714A for any given magnetic flux density and frequency and the ratio of specific core loss of 2714A to 2714AF was dependent on both magnetic flux density and frequency. A comparison was also made of the 2714A, 2714AF, and 6025F materials to two different tape thicknesses of the polycrystalline Supermalloy material and the results show that 2714AF and 6025F have the lowest specific core loss at 100 kHz over the magnetic flux density range of 0.1 to 0.4 Tesla.

  20. A novel magnetic valve using room temperature magnetocaloric materials

    DEFF Research Database (Denmark)

    Eriksen, Dan; Bahl, Christian; Pryds, Nini;

    2012-01-01

    data a 3D finite element model has been set up to calculate the magnetic force between (graded) blocks of these materials and a permanent magnet assembly. The results have been used to calculate equilibrium points for actuation systems where the magnetic force is balanced by a spring force. On the......Magnetocaloric materials with near-room-temperature tuneable Curie temperatures have been utilized to develop a novel magnetic valve technology. The temperature dependent attractive force between the materials and a permanent magnet assembly is used to actuate valves as a response to temperature...... changes. This is made possible by the strong temperature dependence of the magnetization close to the Curie temperature of the magnetocaloric materials. Different compositions of both La0.67(Ca,Sr)0.33MnO3 and La(Fe,Co,Si)13 have been considered for use in prototype valves. Based on measured magnetization...

  1. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer;

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...... square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements as...... a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment....

  2. Magnetic ionic liquids: synthesis and characterization

    International Nuclear Information System (INIS)

    The synthesis of magnetic ionic liquids (MILs) based on the stable dispersions of magnetic nanoparticles (MNPs) of γ-Fe2O3, Fe3O4, and CoFe2O4 in the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2) is reported. The MNPs were obtained by the coprecipitation method. The surface of the α-Fe2O3, Fe3O4, and CoFe2O4 MNPs with mean sizes (XRD) of 9.3, 12.3, and 11.0 nm, respectively were functionalized by 1-n-butyl-3-(3'-trimethoxypropylsilane)- imidazolium chloride. The non functionalized and functionalized MNPs were further characterized by Raman, FTIR-ATR, and FTNIR spectroscopy and by TGA. The stability of the MILs was assigned to the formation of at least one monolayer of the surface modifier agent that mimics the structure of the BMI.NTf2 IL. (author)

  3. Focus on Materials Analysis and Processing in Magnetic Fields

    Directory of Open Access Journals (Sweden)

    Yoshio Sakka, Noriyuki Hirota, Shigeru Horii and Tsutomu Ando

    2009-01-01

    Full Text Available Recently, interest in the applications of feeble (diamagnetic and paramagnetic magnetic materials has grown, whereas the popularity of ferromagnetic materials remains steady and high. This trend is due to the progress of superconducting magnet technology, particularly liquid-helium-free superconducting magnets that can generate magnetic fields of 10 T and higher. As the magnetic energy is proportional to the square of the applied magnetic field, the magnetic energy of such 10 T magnets is in excess of 10 000 times that of conventional 0.1 T permanent magnets. Consequently, many interesting phenomena have been observed over the last decade, such as the Moses effect, magnetic levitation and the alignment of feeble magnetic materials. Researchers in this area are widely spread around the world, but their number in Japan is relatively high, which might explain the success of magnetic field science and technology in Japan.Processing in magnetic fields is a rapidly expanding research area with a wide range of promising applications in materials science. The 3rd International Workshop on Materials Analysis and Processing in Magnetic Fields (MAP3, which was held on 14–16 May 2008 at the University of Tokyo, Japan, focused on various topics including magnetic field effects on chemical, physical, biological, electrochemical, thermodynamic and hydrodynamic phenomena; magnetic field effects on the crystal growth and processing of materials; diamagnetic levitation, the magneto-Archimedes effect, spin chemistry, magnetic orientation, control of structure by magnetic fields, magnetic separation and purification, magnetic-field-induced phase transitions, properties of materials in high magnetic fields, the development of NMR and MRI, medical applications of magnetic fields, novel magnetic phenomena, physical property measurement by magnetic fields, and the generation of high magnetic fields.This focus issue compiles 13 key papers selected from the proceedings

  4. Characterization of material composite marble-polyester

    Directory of Open Access Journals (Sweden)

    Corpas, F. A.

    2002-12-01

    Full Text Available In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. From the results obtained, we deduce then that this material could be used to inside and outside adornment.

    En este trabajo, caracterizamos un nuevo material compuesto, formado con una mezcla de poliéster y de mármol blanco triturado. El propósito final es doble: por un lado obtener un material para aplicaciones lo suficientemente competitivas como para que se pueda iniciar un estudio económico de viabilidad, aumentando el rendimiento de la materia prima y mejorando las salidas laborales de las comarcas extractoras. Para la caracterización del material se ha determinado el porcentaje adecuado de poliéster. Así como las propiedades mecánicas (flexión, compresión y dureza, químicas, fatiga térmica y su influencia a la exposición solar In order to characterized of material, we have determined the suitable porcentage of polyester Also we have carried out a study of the mechanical (stretching, resistance to traction, hardeness and thermal fatigue chemicals properties and solar radiation influence. De los resultados obtenidos, este material podría ser utilizado para ornamentación tanto de interior como de exterior.

  5. Magnetic resonance characterization of silicon nanowires

    Science.gov (United States)

    Fanciulli, Marco; Belli, Matteo; Vellei, Antonio; Canevali, Carmen; Rotta, Davide; Paleari, Stefano; Basini, Martina

    2012-02-01

    Silicon nanowires (SiNWs) have been extensively investigated in the last decades. The interest in these nanostructures stems from both fundamental and applied research motivations. The functional properties of one- and zero-dimensional silicon structures are significantly different, at least below a certain critical dimension, from those well known in the bulk. The key and peculiar functional properties of SiNWs find applications in nanoelectronics, classical and quantum information processing and storage, optoelectronics, photovoltaics, thermoelectric, battery technology, nano-biotechnology, and neuroelectronics. We report our work on the characterization by continuous wave (CW) and pulse electron spin resonance (CW, FT-EPR) and electrically detected magnetic resonance (EDMR) measurements of silicon nanowires (SiNWs) produced by different top-down processes. SiNWs were fabricated starting from SOI wafers using standard e-beam lithography and anisotropic wet etching or by metal-assisted chemical etching. Further oxidation was used to reduce the wire cross section. Different EDMR implementations were used to address the electronic wave function of donors (P, As) and to characterize point defects at the SiNWs/SiO2 interface.

  6. Experimental results for a magnetic refrigerator using three different types of magnetocaloric material regenerators

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Bahl, Christian Robert Haffenden; Nielsen, Kaspar Kirstein

    2011-01-01

    refrigeration device for near room temperature applications, and it is driven by the magnetocaloric effect in the regenerator material. Several magnetocaloric materials with potential magnetic refrigeration applications have recently been developed and characterized; however, few of them have been tested in an...... experimental device. This paper compares the performance of three magnetocaloric material candidates for AMRs, La(Fe,Co,Si)13, (La,Ca,Sr)MnO3 and Gd, in an experimental active magnetic regenerator with a parallel plate geometry. The performance of single-material regenerators of each magnetocaloric material...... family were compared. In an attempt to improve system performance, graded two-material regenerators were made from two different combinations of La(Fe,Co,Si)13 compounds having different magnetic transition temperatures. One combination of the La(Fe,Co,Si)13 materials yielded a higher performance, while...

  7. Solid electrolytes general principles, characterization, materials, applications

    CERN Document Server

    Hagenmuller, Paul

    1978-01-01

    Solid Electrolytes: General Principles, Characterization, Materials, Applications presents specific theories and experimental methods in the field of superionic conductors. It discusses that high ionic conductivity in solids requires specific structural and energetic conditions. It addresses the problems involved in the study and use of solid electrolytes. Some of the topics covered in the book are the introduction to the theory of solid electrolytes; macroscopic evidence for liquid nature; structural models; kinetic models; crystal structures and fast ionic conduction; interstitial motion in

  8. Optical Coherence Tomography for Material Characterization

    OpenAIRE

    Liu, P

    2014-01-01

    Optical coherence tomography (OCT) is a non-invasive, contactless and high resolution imaging method, which allows the reconstruction of two or three dimensional depth-resolved images in turbid media. In the past 20 years, OCT has been extensively developed in the field of biomedical diagnostics, while OCT in the non-destructive testing (NDT) field is lagging far behind. The aim of this thesis is to use OCT as a novel NDT technique for material structure characterization and damage detection....

  9. Matrix Characterization in Threat Material Detection Processes

    Science.gov (United States)

    Obhodas, J.; Sudac, D.; Valkovic, V.

    2009-03-01

    Matrix characterization in the threat material detection is of utmost importance, it generates the background against which the threat material signal has to be identified. Threat materials (explosive, chemical warfare, …) are usually contained within small volume inside large volumes of variable matrices. We have studied the influence of matrix materials on the capability of neutron systems to identify hidden threat material. Three specific scenarios are considered in some details: case 1—contraband material in the sea containers, case 2—-explosives in soil (landmines), case 3—explosives and chemical warfare on the sea bottom. Effects of container cargo material on tagged neutron system are seen in the increase of gamma background and the decrease of neutron beam intensity. Detection of landmines is more complex because of variable soil properties. We have studied in detail space and time variations of soil elemental compositions and in particular hydrogen content (humidity). Of special interest are ammunitions and chemical warfare on the sea bottom, damping sites and leftovers from previous conflicts (WW-I, WW-II and local). In this case sea sediment is background source and its role is similar to the role of the soil in the landmine detection. In addition to geochemical cycling of chemical elements in semi-enclosed sea, like the Adriatic Sea, one has to consider also anthropogenic influence, especially when studying small scale variations in concentration levels. Some preliminary experimental results obtained with tagged neutron sensor inside an underwater vehicle are presented as well as data on sediment characterization by X-Ray Fluorescence.

  10. Matrix Characterization in Threat Material Detection Processes

    International Nuclear Information System (INIS)

    Matrix characterization in the threat material detection is of utmost importance, it generates the background against which the threat material signal has to be identified. Threat materials (explosive, chemical warfare, ...) are usually contained within small volume inside large volumes of variable matrices. We have studied the influence of matrix materials on the capability of neutron systems to identify hidden threat material. Three specific scenarios are considered in some details: case 1--contraband material in the sea containers, case 2 - explosives in soil (landmines), case 3 - explosives and chemical warfare on the sea bottom. Effects of container cargo material on tagged neutron system are seen in the increase of gamma background and the decrease of neutron beam intensity. Detection of landmines is more complex because of variable soil properties. We have studied in detail space and time variations of soil elemental compositions and in particular hydrogen content (humidity). Of special interest are ammunitions and chemical warfare on the sea bottom, damping sites and leftovers from previous conflicts (WW-I, WW-II and local). In this case sea sediment is background source and its role is similar to the role of the soil in the landmine detection. In addition to geochemical cycling of chemical elements in semi-enclosed sea, like the Adriatic Sea, one has to consider also anthropogenic influence, especially when studying small scale variations in concentration levels. Some preliminary experimental results obtained with tagged neutron sensor inside an underwater vehicle are presented as well as data on sediment characterization by X-Ray Fluorescence.

  11. Inkjet printing of magnetic materials with aligned anisotropy

    Science.gov (United States)

    Song, Han; Spencer, Jeremy; Jander, Albrecht; Nielsen, Jeffrey; Stasiak, James; Kasperchik, Vladek; Dhagat, Pallavi

    2014-05-01

    3-D printing processes, which use drop-on-demand inkjet printheads, have great potential in designing and prototyping magnetic materials. Unlike conventional deposition and lithography, magnetic particles in the printing ink can be aligned by an external magnetic field to achieve both high permeability and low hysteresis losses, enabling prototyping and development of novel magnetic composite materials and components, e.g., for inductor and antennae applications. In this work, we report an inkjet printing technique with magnetic alignment capability. Magnetic films with and without particle alignment are printed, and their magnetic properties are compared. In the alignment-induced hard axis direction, an increase in high frequency permeability and a decrease in hysteresis losses are observed. Our results suggest that unique magnetic structures with arbitrary controllable anisotropy, not feasible otherwise, may be fabricated via inkjet printing.

  12. Synthesis, characterization and application of electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    He, L.

    1995-07-07

    It has been known that significant advances in electrochemistry really depend on improvements in the sensitivity, selectivity, convenience, and/or economy of working electrodes, especially through the development of new working electrode materials. The advancement of solid state chemistry and materials science makes it possible to provide the materials which may be required as satisfactory electrode materials. The combination of solid state techniques with electrochemistry expands the applications of solid state materials and leads to the improvement of electrocatalysis. The study of Ru-Ti{sub 4}O{sub 7} and Pt-Ti{sub 4}O{sub 7} microelectrode arrays as introduced in paper 1 and paper 4, respectively, focuses on their synthesis and characterization. The synthesis is described by high temperature techniques for Ru or Pt microelectrode arrays within a conductive Ti{sub 4}O{sub 7} ceramic matrix. The characterization is based on the data obtained by x-ray diffractometry, scanning electron microscopy, voltammetry and amperometry. These microelectrode arrays show significant enhancement in current densities in comparison to solid Ru and Pt electrodes. Electrocatalysis at pyrochlore oxide Bi{sub 2}Ru{sub 2}O{sub 7.3} and Bi{sub 2}Ir{sub 2}O{sub 7} electrodes are described in paper 2 and paper 3, respectively. Details are reported for the synthesis and characterization of composite Bi{sub 2}Ru{sub 2}O{sub 7.3} electrodes. Voltammetric data are examined for evidence that oxidation can occur with transfer of oxygen to the oxidation products in the potential region corresponding to anodic discharge of H{sub 2}O with simultaneous evolution of O{sub 2}. Paper 3 includes electrocatalytic activities of composite Bi{sub 2}Ir{sub 2}O{sub 7} disk electrodes for the oxidation of I{sup -} and the reduction of IO{sub 3}{sup -}.

  13. FOREWORD: Focus on Materials Analysis and Processing in Magnetic Fields Focus on Materials Analysis and Processing in Magnetic Fields

    Science.gov (United States)

    Sakka, Yoshio; Hirota, Noriyuki; Horii, Shigeru; Ando, Tsutomu

    2009-03-01

    Recently, interest in the applications of feeble (diamagnetic and paramagnetic) magnetic materials has grown, whereas the popularity of ferromagnetic materials remains steady and high. This trend is due to the progress of superconducting magnet technology, particularly liquid-helium-free superconducting magnets that can generate magnetic fields of 10 T and higher. As the magnetic energy is proportional to the square of the applied magnetic field, the magnetic energy of such 10 T magnets is in excess of 10 000 times that of conventional 0.1 T permanent magnets. Consequently, many interesting phenomena have been observed over the last decade, such as the Moses effect, magnetic levitation and the alignment of feeble magnetic materials. Researchers in this area are widely spread around the world, but their number in Japan is relatively high, which might explain the success of magnetic field science and technology in Japan. Processing in magnetic fields is a rapidly expanding research area with a wide range of promising applications in materials science. The 3rd International Workshop on Materials Analysis and Processing in Magnetic Fields (MAP3), which was held on 14-16 May 2008 at the University of Tokyo, Japan, focused on various topics including magnetic field effects on chemical, physical, biological, electrochemical, thermodynamic and hydrodynamic phenomena; magnetic field effects on the crystal growth and processing of materials; diamagnetic levitation, the magneto-Archimedes effect, spin chemistry, magnetic orientation, control of structure by magnetic fields, magnetic separation and purification, magnetic-field-induced phase transitions, properties of materials in high magnetic fields, the development of NMR and MRI, medical applications of magnetic fields, novel magnetic phenomena, physical property measurement by magnetic fields, and the generation of high magnetic fields. This focus issue compiles 13 key papers selected from the proceedings of MAP3. Other

  14. Development of a Thin Film Magnetic Moment Reference Material.

    Science.gov (United States)

    Pappas, D P; Halloran, S T; Owings, R R; da Silva, F C S

    2008-01-01

    In this paper we present the development of a magnetic moment reference material for low moment magnetic samples. We first conducted an inter-laboratory comparison to determine the most useful sample dimensions and magnetic properties for common instruments such as vibrating sample magnetometers (VSM), SQUIDs, and alternating gradient field magnetometers. The samples were fabricated and then measured using a vibrating sample magnetometer. Their magnetic moments were calibrated by tracing back to the NIST YIG sphere, SRM 2853. PMID:27096108

  15. High temperature material characterization and advanced materials development

    International Nuclear Information System (INIS)

    The study is to characterize the structural materials under the high temperature, one of the most significant environmental factors in nuclear systems. And advanced materials are developed for high temperature and/or low activation in neutron irradiation. Tensile, fatigue and creep properties have been carried out at high temperature to evaluate the mechanical degradation. Irradiation tests were performed using the HANARO. The optimum chemical composition and heat treatment condition were determined for nuclear grade 316NG stainless steel. Nitrogen, aluminum, and tungsten were added for increasing the creep rupture strength of FMS steel. The new heat treatment method was developed to form more stable precipitates. By applying the novel whiskering process, high density SiC/SiC composites with relative density above 90% could be obtained even in a shorter processing time than the conventional CVI process. Material integrated databases are established using data sheets. The databases of 6 kinds of material properties are accessible through the home page of KAERI material division

  16. High temperature material characterization and advanced materials development

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, D. H.; Kim, S. H. and others

    2005-03-15

    The study is to characterize the structural materials under the high temperature, one of the most significant environmental factors in nuclear systems. And advanced materials are developed for high temperature and/or low activation in neutron irradiation. Tensile, fatigue and creep properties have been carried out at high temperature to evaluate the mechanical degradation. Irradiation tests were performed using the HANARO. The optimum chemical composition and heat treatment condition were determined for nuclear grade 316NG stainless steel. Nitrogen, aluminum, and tungsten were added for increasing the creep rupture strength of FMS steel. The new heat treatment method was developed to form more stable precipitates. By applying the novel whiskering process, high density SiC/SiC composites with relative density above 90% could be obtained even in a shorter processing time than the conventional CVI process. Material integrated databases are established using data sheets. The databases of 6 kinds of material properties are accessible through the home page of KAERI material division.

  17. Preparation and characterization of magnetic nanoparticles with controlled magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Herea, Dumitru-Daniel, E-mail: dherea@phys-iasi.ro; Chiriac, Horia; Lupu, Nicoleta [National Institute of Research and Development for Technical Physics (Romania)

    2011-09-15

    The effect of molar ratio of two hydrated iron salts used as precursors into a (co)precipitation-based synthesis method, on the composition, size and specific saturation magnetization of mixed iron oxides and oxyhydroxides magnetic nanoparticles as reaction products, was studied. The preparation procedure is based on a salt-assisted solid-state chemical reaction. The obtained products are magnetic multiphase components with the mean size ranging from 3 to 10 nm and specific saturation magnetization between 25 and 95.5 emu/g. The specific saturation magnetization modifies in a non-linear manner as the molar ratio of the iron salts varies. Excepting one sample, for which Fe{sup 2+}/Fe{sup 3+} molar ratio was zero, all magnetic nanoparticles show a ferrofluid-like behaviour in the colloidal form. The small size, ferrofluid-like behaviour, and controlled specific saturation magnetization allow the use of new synthesized nanoparticles in specific biomedical or industrial applications.

  18. Ultrasonic Nondestructive Characterization of Porous Materials

    Science.gov (United States)

    Yang, Ningli

    2011-12-01

    Wave propagation in porous media is studied in a wide range of technological applications. In the manufacturing industry, determining porosity of materials in the manufacturing process is required for strict quality control. In the oil industry, acoustic signals and seismic surveys are used broadly to determine the physical properties of the reservoir rock which is a porous media filled with oil or gas. In porous noise control materials, a precise prediction of sound absorption with frequency and evaluation of tortuosity are necessary. Ultrasonic nondestructive methods are a very important tool for characterization of porous materials. The dissertation deals with two types of porous media: materials with relatively low and closed porosity and materials with comparatively high and open porosity. Numerical modeling, Finite Element simulations and experimental characterization are all discussed in this dissertation. First, ultrasonic scattering is used to determine the porosity in porous media with closed pores. In order get a relationship between the porosity in porous materials and ultrasonic scattering independently and to increase the sensitivity to obtain scattering information, ultrasonic imaging methods are applied and acoustic waves are focused by an acoustic lens. To verify the technique, engineered porous acrylic plates with varying porosity are measured by ultrasonic scanning and ultrasonic array sensors. Secondly, a laser based ultrasonic technique is explored for predicting the mechanical integrity and durability of cementitious materials. The technique used involves the measurement of the phase velocity of fast and slow longitudinal waves in water saturated cement paste. The slow wave velocity is related to the specimen's tortuosity. The fast wave speed is dependent on the elastic properties of porous solid. Experimental results detailing the generation and detection of fast and slow wave waves in freshly prepared and aged water-saturated cement samples

  19. Production, handling and characterization of particulate materials

    CERN Document Server

    Meesters, Gabriel

    2016-01-01

    This edited volume presents most techniques and methods that have been developed by material scientists, chemists, chemical engineers and physicists for the commercial production of particulate materials, ranging from the millimeter to the nanometer scale.  The scope includes the physical and chemical background, experimental optimization of equipment and procedures, as well as an outlook on future methods. The books addresses  issues of industrial importance such as specifications, control parameter(s), control strategy, process models, energy consumption and discusses the various techniques in relation to potential applications. In addition to the production processes, all major unit operations and characterization methods are described in this book. It differs from other books which are devoted to a single technique or a single material. Contributors to this book are acknowledged experts in their field. The aim of the book is to facilitate comparison of the different unit operations leading to optimum...

  20. High Field Pulse Magnets with New Materials

    Science.gov (United States)

    Li, L.; Lesch, B.; Cochran, V. G.; Eyssa, Y.; Tozer, S.; Mielke, C. H.; Rickel, D.; van Sciver, S. W.; Schneider-Muntau, H. J.

    2004-11-01

    High performance pulse magnets using the combination of CuNb conductor and Zylon fiber composite reinforcement with bore sizes of 24, 15 and 10 mm have been designed, manufactured and tested to destruction. The magnets successfully reached the peak fields of 64, 70 and 77.8 T respectively with no destruction. Failures occurred near the end flanges at the layer. The magnet design, manufacturing and testing, and the mode of the failure are described and analyzed.

  1. Molecular magnetic materials based on porphyrin macrocyles

    OpenAIRE

    ÖNAL, Emel

    2014-01-01

    The preparation of Molecule-Based Magnets is based on the assembling carriers of magnetic moment. These may be the metal ions only with diamagnetic linkers or the metal ions connected through open-shell organic molecule. The building of novel Molecule-Based Magnets architectures following the metal-radical approach relies on the design of innovative open-shell organic molecular blocks. In this regard, we focus our strategy on the synthesis of porphyrins incorporating free radicals. Indeed, po...

  2. Synthesis and characterization of magnetic palygorskite nanoparticles and their application on methylene blue remotion from water

    International Nuclear Information System (INIS)

    Highlights: • Nanopalygorskites’ surface modification was confirmed by characterization. • The magnetism of nanoparticles was characterized by different techniques. • Methylene blue was easily removed using the magnetic nanopalygorskites. - Abstract: Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10−4 Am2/kg to about 20 Am2/kg. A weight loss was also observed around 277 °C–339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite

  3. Magnetic and rheological characterization of novel ferrofluids

    International Nuclear Information System (INIS)

    A new type of magnetic fluid containing silica-coated magnetic nanoparticles has been synthesized. The particles are produced by a flame synthesis and have been dispersed in an oily medium to obtain the magnetic fluid. By means of magnetic and rheological investigations the basic properties of these fluids were determined. It could be seen, that the fluids show the well known paramagnetic behavior of ferrofluids with a small hysteresis due to the large domain size of the magnetic particles. Moreover strong dependencies of the rheological functions on magnetic field strength could be observed

  4. Synthesis and Characterization of Polymer-Templated Magnetic Nanoparticles

    Science.gov (United States)

    Tamakloe, Beatrice

    This research reports on the investigation into the synthesis and stabilization of iron oxide nanoparticles for theranostic applications using amine-epoxide polymers. Although theranostic agents such as magnetic nanoparticles have been designed and developed for a few decades, there is still more work that needs to be done with the type of materials that can be used to stabilize or functionalize these particles if they are to be used for applications such as drug delivery, imaging and hyperthermia. For in-vivo applications, it is crucial that organic coatings enclose the nanoparticles in order to prevent aggregation and facilitate efficient removal from the body as well as protect the body from toxic material. The objective of this thesis is to design polymer coated magnetite nanoparticles with polymers that are biocompatible and can stabilize the iron oxide nanoparticle to help create mono-dispersed particles in solution. It is desirable to also have these nanoparticles possess high magnetic susceptibility in response to an applied magnetic field. The co-precipitation method was selected because it is probably the simplest and most efficient chemical pathway to obtain magnetic nanoparticles. In literature, cationic polymers such as Polyethylenimine (PEI), which is the industry standard, have been used to stabilize IONPs because they can be used in magnetofections to deliver DNA or RNA. PEI however is known to interact very strongly with proteins and is cytotoxic, so as mentioned previously the Iron Oxide nanoparticles (IONPs) synthesized in this study were stabilized with amine-epoxide polymers because of the limitations of PEI. Four different amine-epoxide polymers which have good water solubility, biodegradability and less toxic than PEI were synthesized and used in the synthesis and stabilization of the magnetic nanoparticles and compared to PEI templated IONPs. These polymer-templated magnetic nanoparticles were also characterized by size, surface charge, Iron

  5. Development of Rapidly Quenched Soft Magnetic Materials in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The discovery of the first Fe-based ferromagnetic amorphous alloy in 1966 had made an impact on conventional magnetic materials because of its unique properties. Since then, a number of amorphous magnetic materials have been successfully developed and used in a wide variety of applications. A brief review of R & D activities on amorphous soft magnetic materials in China is given from the beginning to the present in a somewhat chronological order, followed by a brief introduction to their applications on electric and electronic industries. An analysis and a prospect of Chinese market of such amorphous materials are also presented.

  6. Opto-nanomechanical spectroscopic material characterization

    Science.gov (United States)

    Tetard, L.; Passian, A.; Farahi, R. H.; Thundat, T.; Davison, B. H.

    2015-10-01

    The non-destructive, simultaneous chemical and physical characterization of materials at the nanoscale is an essential and highly sought-after capability. However, a combination of limitations imposed by Abbe diffraction, diffuse scattering, unknown subsurface, electromagnetic fluctuations and Brownian noise, for example, have made achieving this goal challenging. Here, we report a hybrid approach for nanoscale material characterization based on generalized nanomechanical force microscopy in conjunction with infrared photoacoustic spectroscopy. As an application, we tackle the outstanding problem of spatially and spectrally resolving plant cell walls. Nanoscale characterization of plant cell walls and the effect of complex phenotype treatments on biomass are challenging but necessary in the search for sustainable and renewable bioenergy. We present results that reveal both the morphological and compositional substructures of the cell walls. The measured biomolecular traits are in agreement with the lower-resolution chemical maps obtained with infrared and confocal Raman micro-spectroscopies of the same samples. These results should prove relevant in other fields such as cancer research, nanotoxicity, and energy storage and production, where morphological, chemical and subsurface studies of nanocomposites, nanoparticle uptake by cells and nanoscale quality control are in demand.

  7. Preparation and Characterization of Nonylphenol Magnetic Molecularly Imprinted Polymer

    International Nuclear Information System (INIS)

    Nonylphenol (NP) is a toxic xenobiotic compound classified as an endocrine disrupter, which can interface with the hormonal system of numerous organisms, and then cause a series of pathological changes. It is of great significance to remove nonyl phenol from the environment. In this paper, an effective method for the preparation of molecularly imprinted nanoparticles was reported. Firstly, Fe/sub 3/O/sub 4/ at the rate SiO/sub 2/ magnetic carrier material modified by trimethoxysilane was achieved through three-step reaction. After that, the selective magnetic molecularly imprinted polymer sorbent for NP (Fe/sub 3/O/sub 4/ at the rate SiO/sub 2/-MIP) was synthesized by surface molecular imprinting technique, using NP as template, 4-vinyl pyridine(4-Vpy) as functional monomers, ethylene glycol dimethacrylate (EGDMA) as cross linker and azobisisobutyronitrile (AIBN) as initiator. The morphous, composition, structure and performance of polymer adsorbent was characterized by SEM, TEM, FT-IR, XRD, EDS, VSM and nitrogen adsorption-desorption techniques. The results indicated that the polymer adsorbent was successfully prepared. The size of the polymer particle was about 50 nm, the aperture on the surface was 3.71 nm, the BET specific surface area was 61.80 m/sup 2/g and the Langmuir specific surface area was 101.24 m/sup 2/g. The selective adsorption rate for NP of 0.5 mmol/L attained value of 86.5%, and for NP with low concentration (less than 2.0 mg/L), the selective adsorption rate reached more than 90%. The synthesized magnetic molecularly imprinted polymer had higher selective recognition ability towards the template molecule nonylphenol. It has good magnetism and can be rapidly separated after being employed by using adscititious magnetic field. It has potential application value in treatment and enrichment of nonylphenol. (author)

  8. Characterization of ferrimagnetic and dielectric materials with a rectangular waveguide-method, limits of validity

    International Nuclear Information System (INIS)

    The development of passive components in the microwave range for telecommunication applications is a major focus for the next years. Some microwave passive components (such as circulators, isolators, etc.) still use magnetic materials. It is then necessary to characterize the electromagnetic properties of such materials, their scattering behaviours and to eventually highlight a non-reciprocal propagation. A method for the dielectric and magnetic characterization of multi-layer materials in the X-band (8.2-12.4 GHz) is presented as well as its reliability and its domain of validity. It allows to determine the elements of the permeability tensor of ferrite sample

  9. Characterization of unknown objects containing radioactive materials

    International Nuclear Information System (INIS)

    Fraunhofer-INT is going to equip a transportable container with a system for the detection, identification and characterization of radioactive material inside objects with unknown content. This system will be a prototype for a mobile system to detect illicit trafficking of radioactive and especially nuclear material and will thus prohibit nuclear proliferation. This container will be equipped with systems for passive and active nondestructive measurements. For active measurements we use a sealed tube 14 MeV neutron generator with an without a moderating assembly between the interrogating neutron source and the object of interest. Because stolen or diverted radioactive material generally may not have a fixed geometry and will not be packaged in standard containers the main emphasis in this paper is on in-situ gamma measurements taking into account possible shielding around the radioactive source. High-resolution gamma measurements were performed on radioactive material behind different types of shielding. The measured data were evaluated by modeling the different parameters like the wall thickness of the box, matrix and shielding material inside and so on. Comparison with the actual experimental setup of the models showed good agreement and proved the power of this method. In this way significant information was gained on the content of the unknown box, which is important for further actions. (author)

  10. Control over magnetic properties in bulk hybrid materials

    Science.gov (United States)

    Urban, Christian; Quesada, Adrian; Saerbeck, Thomas; Rubia, Miguel Angel De La; Garcia, Miguel Angel; Fernandez, Jose Francisco; Schuller, Ivan K.; UCSD Collaboration; Instituto de Ceramica, Madrid Collaboration; Institut Laue-Langevin, Grenoble Collaboration

    We present control of coercivity and remanent magnetization of a bulk ferromagnetic material embedded in bulk vanadium sesquioxide (V2O3) by using a standard bulk synthesis procedure. The method generalizes the use of structural phase transitions of one material to control structural and magnetic properties of another. A structural phase transition (SPT) in the V2O3 host material causes magnetic properties of Ni to change as function of temperature. The remanent magnetization and the coercivity are reversibly controlled by the SPT without additional external magnetic fields. The reversible tuning shown here opens the pathway for controlling the properties of a vast variety of magnetic hybrid bulk systems. This Work is supported by the Office of Basic Energy Science, U.S. Department of Energy, BES-DMS funded by the Department of Energy's Office of Basic Energy Science, DMR under grant DE FG02 87ER-45332.

  11. Plasma characterization studies for materials processing

    Energy Technology Data Exchange (ETDEWEB)

    Pfender, E.; Heberlein, J. [Univ. of Minnesota, Minneapolis, MN (United States)

    1995-12-31

    New applications for plasma processing of materials require a more detailed understanding of the fundamental processes occurring in the processing reactors. We have developed reactors offering specific advantages for materials processing, and we are using modeling and diagnostic techniques for the characterization of these reactors. The emphasis is in part set by the interest shown by industry pursuing specific plasma processing applications. In this paper we report on the modeling of radio frequency plasma reactors for use in materials synthesis, and on the characterization of the high rate diamond deposition process using liquid precursors. In the radio frequency plasma torch model, the influence of specific design changes such as the location of the excitation coil on the enthalpy flow distribution is investigated for oxygen and air as plasma gases. The diamond deposition with liquid precursors has identified the efficient mass transport in form of liquid droplets into the boundary layer as responsible for high growth, and the chemical properties of the liquid for the film morphology.

  12. Ferromagnetic nanocomposites as spintronic materials with controlled magnetic structure

    International Nuclear Information System (INIS)

    The physical properties of ferromagnetic dilute magnetic semiconductors and nanocomposites are considered. The latter have several advantages as spintronic materials with a controlled magnetic structure for weak magnetic field sensors. A characteristic feature of ferromagnetic nanocomposites is the spin dependent tunneling conductance, which is responsible for negative and positive magnetoresistance. The magnetoresistive effects have a wide range of applications. In particular, materials with such effects may be used in the development of magnetoresistive memory devices, weak magnetic field sensors, medical diagnostic devices and other items of electronic equipment.

  13. Characterizations of Some Semi magnetic Chalcopyrite Compounds

    International Nuclear Information System (INIS)

    circuit for all investigated thin film samples. The ESR spectra of the Cd0.5Zn0.5X0.02Se (X= Mn, Fe and Co) powder samples were studied at room temperature. The obtained results showed that all samples were paramagnetic materials at the room temperature. The g-factor and concentration of paramagnetic defects were determined. The magnetic properties (hysteresis loops and ZFC/FC curves) were studied in temperature range from 5 K to 200 K. The obtained results indicated the ferromagnetic exchange interaction between the magnetic ions in case of Cd0.5Zn0.5Fe0.02Se and Cd0.5Zn0.5Co0.02Se but did not indicate conventional ferromagnetism, samples exhibit spin-glass behavior and also indicated antiferromagnetic interaction between Mn2+ ions in case of Cd0.5Zn0.5Mn0.02Se sample.

  14. Photothermal characterization of functionally graded materials (FGM)

    International Nuclear Information System (INIS)

    This paper deals with the photothermal characterization of functionally graded materials (FGM) whose thermal properties are varying parallel to the sample surface. Simple experimental configurations and associated inversion procedures are proposed either for thermal mapping or for pitch-catch imaging mode. The photothermally induced periodic temperature field at the sample surface is first calculated using a specific code, then the inversion procedures are checked using a simulated set of data. Preliminary experimental results are presented outlining need of specific filter to cope with experimental noise

  15. Surface, interface and bulk materials characterization using Indus synchrotron sources

    International Nuclear Information System (INIS)

    Synchrotron radiation sources, providing intense, polarized and stable beams of ultra violet, soft and hard x-ray photons, are having great impact on physics, chemistry, biology, materials science and other areas research. In particular synchrotron radiation has revolutionized materials characterization techniques by enhancing its capabilities for investigating the structural, electronic and magnetic properties of solids. The availability of synchrotron sources and necessary instrumentation has led to considerable improvements in spectral resolution and intensities. As a result, application scope of different materials characterization techniques has tremendously increased particularly in the analysis of solid surfaces, interfaces and bulk materials. The Indian synchrotron storage ring, Indus-1 and Indus-2 are in operation at RRCAT, Indore. The UGC-DAE CSR with the help of university scientist had designed and developed an angle integrated photoelectron spectroscopy (AlPES) beam line on Indus-1 storage ring of 450 MeV and polarized light beam line for soft x-ray absorption spectroscopy (SXAS) on Indus-2 storage ring of 2.5 GeV. (author)

  16. Smart Optical Material Characterization System and Method

    Science.gov (United States)

    Choi, Sang Hyouk (Inventor); Park, Yeonjoon (Inventor)

    2015-01-01

    Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

  17. Magnetoscience magnetic field effects on materials, fundamentals and applications

    CERN Document Server

    Yamaguchi, Masuhiro

    2007-01-01

    It is a dream of chemists and physicists to use magnetism, an important physical property of many materials, to control chemical and physical processes. With new manufacturing technologies for superconducting magnets, it has become possible to produce strong magnetic fields of 10 Tesla or more for applications in chemistry and physics. New magnetic phenomena, useful for processing functional molecules with improved quality, have been discovered recently. They open up exciting possibilities for studying and applying magnetic field effects in the chemical and physical processes of diamagnetic, p

  18. High frequency processes in magnetic materials

    CERN Document Server

    Srinivasan, G

    1995-01-01

    This review volume deals with recent advances in topics of importance to scientists and engineers involved in research and device development utilizing magnetic oxides and multilayers. The subject matter covered includes linear and nonlinear high frequency magnetic excitations and interaction between magnons and photons. In particular, this book contains detailed discussion on the detection of magnons by Brillouin light scattering and photothermal spectroscopy, interaction between spin waves and optical guided modes, microwave solitons, and spin wave instabilities. Recent advances in tradition

  19. Photothermal speckle modulation for noncontact materials characterization.

    Science.gov (United States)

    Stolyarov, Alexander M; Sullenberger, Ryan M; Crompton, David R; Jeys, Thomas H; Saar, Brian G; Herzog, William D

    2015-12-15

    We have developed a noncontact, photothermal materials characterization method based on visible-light speckle imaging. This technique is applied to remotely measure the infrared absorption spectra of materials and to discriminate materials based on their thermal conductivities. A wavelength-tunable (7.5-8.7 μm), intensity-modulated, quantum cascade pump laser and a continuous-wave 532 nm probe laser illuminate a sample surface such that the two laser spots overlap. Surface absorption of the intensity-modulated pump laser induces a time-varying thermoelastic surface deformation, resulting in a time-varying 532 nm scattering speckle field from the surface. The speckle modulation amplitude, derived from a series of visible camera images, is found to correlate with the amplitude of the surface motion. By tuning the pump laser's wavelength over a molecular absorption feature, the amplitude spectrum of the speckle modulation is found to correlate to the IR absorption spectrum. As an example, we demonstrate this technique for spectroscopic identification of thin polymeric films. Furthermore, by adjusting the rate of modulation of the pump beam and measuring the associated modulation transfer to the visible speckle pattern, information about the thermal time constants of surface and sub-surface features can be revealed. Using this approach, we demonstrate the ability to distinguish between different materials (including metals, semiconductors, and insulators) based on differences in their thermal conductivities. PMID:26670512

  20. Induced magnetic ordering transition in RCo5 type materials

    International Nuclear Information System (INIS)

    The magnetism in several materials of the RCo5 type is studied. A numerical calculation scheme, based on an induced magnetic ordering transition, is set up. Using this scheme, and previously reported crystalline electric and magnetic exchange fields parameters, the magnetic structure in R1−yYyCo3B2 and R(Co1−xNix)5 materials (R=Tb and Ho), and its temperature evolution, is calculated, and compared with the corresponding observed results. It is proposed that the magnetic order in the materials of the RCO5 type, with R3+ of integral J, is driven by an induced transition. - Highlights: • A numerical calculations scheme, that simulates induced transition magnetic ordering in R1−yYyCo3B2 and R(Co1−xNix)5 type materials, is set up. • The observed ordered magnetic moment of the R sub-lattice, as function of the magnetic exchange field, and as function of temperature, is shown to agree with induced transition theory, and not with Curie–Weiss theory. • In R1−yYyCo3B2, the relative magnitudes of the crystalline electric field and the magnetic exchange field are just above the critical threshold for induced transition ordering, making them the best experimental ‘realization’ found so far

  1. Deflection of weakly magnetic materials by superconducting OGMS

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, J.; Gerber, R.; Fletcher, D.; Parker, M.R.

    1988-03-01

    Applications of a superconducting Open Gradient Magnetic Separator to fractional separation in air of weakly magnetic materials are presented. The dependence of particle deflection of these materials on the magnetic field strength, release location, magnetic susceptibility, particle density and other properties is investigated. The aim is to maximise the deflection of the magnetically stronger component of the feed to facilitate its separation from the particle stream round the magnet. Materials (e.g. CuSO/sub 4/, MnO/sub 2/) with chi/rho- ratios of the order of 7 x 10/sup -8/ m/sup 3//kg have been deflected. The applicability of dry magnetic separation has thus been considerably extended since up to now the separation of such materials has been restricted to High Gradient Magnetic Separation. The dependence of the separation efficiency upon the method of feeding and the influence of the residence time are studied in order to establish the optimum parameters for the recovery of the desired fraction. The experimental results are compared with predictions of a theory that is based upon novel approximative calculations of magnetic fields in which the use of elliptic integrals is avoided.

  2. Deflection of weakly magnetic materials by superconducting OGMS

    International Nuclear Information System (INIS)

    Applications of a superconducting Open Gradient Magnetic Separator to fractional separation in air of weakly magnetic materials are presented. The dependence of particle deflection of these materials on the magnetic field strength, release location, magnetic susceptibility, particle density and other properties is investigated. The aim is to maximise the deflection of the magnetically stronger component of the feed to facilitate its separation from the particle stream round the magnet. Materials (e.g. CuSO/sub 4/, MnO/sub 2/) with chi/rho- ratios of the order of 7 x 10/sup -8/ m/sup 3//kg have been deflected. The applicability of dry magnetic separation has thus been considerably extended since up to now the separation of such materials has been restricted to High Gradient Magnetic Separation. The dependence of the separation efficiency upon the method of feeding and the influence of the residence time are studied in order to establish the optimum parameters for the recovery of the desired fraction. The experimental results are compared with predictions of a theory that is based upon novel approximative calculations of magnetic fields in which the use of elliptic integrals is avoided

  3. Concepts of tunable magnets using permanent magnetic material for synchrotron radiation sources

    International Nuclear Information System (INIS)

    Novel tunable magnets using permanent magnetic materials (PMMs) are proposed for the magnetic lattice of the 3 GeV Sirius storage ring. Many essential qualitative aspects are discussed including the low and high field dipole designs using PMMs. Studies for quadrupoles and sextupoles were also performed, but as an alternative way, which depends on field requirements

  4. Magnetic Materials Suitable for Fission Power Conversion in Space Missions

    Science.gov (United States)

    Bowman, Cheryl L.

    2012-01-01

    Terrestrial fission reactors use combinations of shielding and distance to protect power conversion components from elevated temperature and radiation. Space mission systems are necessarily compact and must minimize shielding and distance to enhance system level efficiencies. Technology development efforts to support fission power generation scenarios for future space missions include studying the radiation tolerance of component materials. The fundamental principles of material magnetism are reviewed and used to interpret existing material radiation effects data for expected fission power conversion components for target space missions. Suitable materials for the Fission Power System (FPS) Project are available and guidelines are presented for bounding the elevated temperature/radiation tolerance envelope for candidate magnetic materials.

  5. Utilizing Materials With Controllable Curie Temperatures for Magnetic Actuation Purposes

    DEFF Research Database (Denmark)

    Eriksen, Dan; Bahl, Christian R.H.; Smith, Anders;

    2013-01-01

    system. On the basis of forces predicted by the model a number of equilibrium points were calculated for a system where the magnetic force on a ferromagnetic block of material is balanced by a linear spring force. It is shown how these calculation procedures can be used as a tool for designing autonomous......The magnetic force between a permanent magnet and different blocks of ferromagnetic materials was measured and calculated as a function of distance and temperature in the vicinity of the Curie temperature of the materials. The calculations were carried out using a 3-D finite-element model of the...

  6. MSWI boiler fly ashes: magnetic separation for material recovery.

    Science.gov (United States)

    De Boom, Aurore; Degrez, Marc; Hubaux, Paul; Lucion, Christian

    2011-07-01

    Nowadays, ferrous materials are usually recovered from Municipal Solid Waste Incineration (MSWI) bottom ash by magnetic separation. To our knowledge, such a physical technique has not been applied so far to other MSWI residues. This study focuses thus on the applicability of magnetic separation on boiler fly ashes (BFA). Different types of magnet are used to extract the magnetic particles. We investigate the magnetic particle composition, as well as their leaching behaviour (EN 12457-1 leaching test). The magnetic particles present higher Cr, Fe, Mn and Ni concentration than the non-magnetic (NM) fraction. Magnetic separation does not improve the leachability of the NM fraction. To approximate industrial conditions, magnetic separation is also applied to BFA mixed with water by using a pilot. BFA magnetic separation is economically evaluated. This study globally shows that it is possible to extract some magnetic particles from MSWI boiler fly ashes. However, the magnetic particles only represent from 23 to 120 g/kg of the BFA and, though they are enriched in Fe, are composed of similar elements to the raw ashes. The industrial application of magnetic separation would only be profitable if large amounts of ashes were treated (more than 15 kt/y), and the process should be ideally completed by other recovery methods or advanced treatments. PMID:21306886

  7. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation; Caracterizacao da granalha de aco recuperada do residuo de rochas ornamentais por separacao magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Junca, E.; Telles, V.B.; Rodrigues, G.F.; Oliveira, J.R. de; Tenorio, J.A.S., E-mail: eduardojunca@gmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)

    2010-07-01

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 {mu}m with 4 wt.% over 100 {mu}m and content metallic iron of 93 wt%. (author)

  8. Magnetic separation as a method to assist mineralogical characterization of rocks by X-ray diffraction

    International Nuclear Information System (INIS)

    The X-ray diffraction (XRD) corresponds to one of the main techniques for characterization of structures in crystalline materials widely used in the identification of minerals in samples of geological materials such as rocks. However, the large number of mineral phases present in a rock sample can generate excess peaks in the diffractogram, and it can promote overlapping peaks and induce erroneous identification. The purpose of this study was to perform magnetic separation of minerals from rock samples in order to enable the identification of the minerals by XRD. For this magnetic separation, two samples of rock were selected: a sample of high silica content and a sample with low silica content. The magnetic separation of minerals from each sample was performed using the magnetic separator isodynamic Frantz. Posteriorly, the fractions obtained in magnetic separations were analyzed by XRD. In the sample with high silica content, it was obtained a fraction where was identified the accessory mineral epidote, which had not been identified in the total sample diffractogram. In the sample with low silica content, the magnetic separation into several mineral fractions made possible to obtain diffraction patterns with fewer peaks and peaks with higher relative intensities, which allowed its mineralogical characterization. The results showed that the mineral separation by the magnetic separator Frantz made the identification of accessory minerals by XRD and the characterization of samples which have many mineral phases possible, which proves that magnetic separation by Frantz is a method which can assist analyses by XRD. (author)

  9. Characterization of damping in microfibrous material

    Science.gov (United States)

    Soobramaney, Pregassen; Flowers, George T.; Dean, Robert N.

    2012-04-01

    MEMS gyroscopes are used in many applications including harsh environments such as high-power, high-frequency acoustic noise. If the latter is at the natural frequency of the gyroscope, the proof mass will be overexcited giving rise to a corrupted gyroscope output. To mitigate the effect of the high-power, high-frequency acoustic noise, it is proposed to use nickel microfibrous sheets as an acoustic damper. For this purpose, the characterization of vibration damping in Nickel microfibrous sheets was examined in the present research effort. The sheets were made from nickel fibers with cellulose as a binding agent using a wet-lay papermaking technique. Sintering was done at 1000 °C to remove all the cellulose giving rise to a porous material. Square sheets of 20 cm were made from three diameters of nickel fibers namely 4, 8, and 12 microns. The sheets were cut into smaller pieces to fit the requirements of a fixture specially designed for this study. The fixture was attached to a LDS V408 shaker with a mass resting on a stack of the microfibrous sheets to simulate transmitted vibration by base motion with the sheet stack acting as a damper. A series of experiments was conducted using these 3 fiber diameters, different number of layers of microfibrous sheets and varying the vibration amplitude. From the collected vibration data, the stiffness and damping ratio of the microfibrous material was characterized.

  10. Characterization of the materials for functional application

    International Nuclear Information System (INIS)

    The development of material products with extended performances has been equally pushed by the advancement of analysis techniques. Characterization of materials for functional application will be a challenge for further analytical methodology development. In this lecture, several characterization techniques will be outlined and emphasized with respect to special function applications as follows. 1. Phase analysis, crystallite size and microstrain of chemically synthesized ceramic powders in relation to phase transformation. 2. Microstructural evolution and reliability test in the solder joint of microelectronic package. The growth morphology of the intermetallic compound and its effects on the solder joint reliability will be highlighted and discussed. 3. Mechanical properties of thin films and metallized substrates, including adhesion strength, microhardness, scratch behavior, wear resistance. Special interest will be focused on the indentation-scratch deformation associated with the coating/substrate assembly. Employment of atomic force microscope in the evaluation of nano-tribology will also be probed. 4. Diffusion-related kinetics at interface by means of theoretical modelling and electron microanalysis. (author)

  11. A modified free decay test apparatus for the characterization of soft magnetic gels in the presence of magnetic fields

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao. P, Maniprakash.S, & Srinivasan.S.M

    2010-06-01

    Full Text Available This paper presents the development of a simple free decay test apparatus that can be a cost effective alternative to the popular expensive dynamical mechanical analyzers useful for characterization of the dynamic characteristics of soft magnetic composite gels in the presence of variable magnetic field. This apparatus also addresses the common difficulty faced in dynamical mechanical analyzers to conduct the characteristics of deformation dependent mechanical characteristics especially for large deformations, sometimes to the order of 100% that may be necessary for highly compliant polymeric materials. In addition, this apparatus can easily be fitted or modified to facilitate the application of magnetic field. The apparatus is designed to test thin sheet specimens of the magnetic gels in the shear mode at room temperature. As an example, magnetic composite gels prepared with micron sized polarizable particles (carbonyl iron particles interspersed in a polymer matrix gel are used to show the effectiveness of the apparatus. The compliance of this magnetic gel can be varied under the influence of an external magnetic field. Deviations from the linear material behavior can be captured using the appropriate equations that relate the linear assumptions made. Such deviations can then be used in determining the large deformation dependent characteristics of the gel specimen. Thus, it is demonstrated that the apparatus is a cost effective and useful tool for purposes of testing soft and compliant magnetic composite gels used for damping applications.

  12. Magnetic flux dynamics in superconducting materials

    International Nuclear Information System (INIS)

    The magnetization curves, the Bean-Livingston barrier in type I and type II superconductors, the ac magnetic response, the effects of thermal fluctuations on the magnetic behavior and the different dissipation mechanism at microwave frequencies are investigated in mesoscopic superconductors.For small mesoscopic samples we study the peaks and discontinuous jumps found in the magnetization as a function of magnetic field.To interpret these jumps we consider that vortices located inside the sample induce a reinforcement of the Bean- Livingston surface barrier at fields greater than the first penetration field Hp1.This leads to multiple penetration fields Hpi Hp1;Hp2;Hp3;... for vortex entrance in mesoscopic samples.For low-Tc mesoscopic superconductors we found that the meta-stable states due to the surface barrier have a large half-life time, which leads to the hysteresis in the magnetization curves as observed experimentally.A very different behavior appears for high-Tc mesoscopic superconductors where thermally activated vortex entrance/exit through surface barriers is frequent.This leads to a reduction of the magnetization and a non-integer average number of flux quanta penetrating the superconductor.At microwave frequencies we found that each vortex penetration event produces a significant suppression of the ac losses since the imaginary part of the ac susceptibility X(Hdc) as a function of the magnetic field (Hdc) increases before the penetration of vortices and then it decreases abruptly after vortices have entered into the sample.We show that nascent vortices (vortices that are partly inside the sample and nucleated at the surface) play an important role in the dynamic behavior of mesoscopic samples. In type I macroscopic superconductors with first-principles simulations of the TDGL equations we have been able to reproduce several features of the intermediate state observed in experiments.Particularly, droplet and striped patterns are obtained depending on the

  13. Applications of high dielectric materials in high field magnetic resonance

    Science.gov (United States)

    Haines, Kristina Noel

    At high magnetic fields, radiation losses, wavelength effects, self-resonance, and the high resistance of components all contribute to losses in conventional RF MRI coil designs. The hypothesis tested here is that these problems can be combated by the use of high permittivity ceramic materials at high fields. High permittivity ceramic dielectric resonators create strong uniform magnetic fields in compact structures at high frequencies and can potentially solve some of the challenges of high field coil design. In this study NMR probes were constructed for operation at 600 MHz (14.1 Tesla) and 900 MHz (21.1 Tesla) using inductively fed CaTiO3 (relative permittivity of 156-166) cylindrical hollow bore dielectric resonators. The designs showed the electric field is largely confined to the dielectric itself, with near zero values in the hollow bore, which accommodates the sample. The 600 MHz probe has an unmatched Q value greater than 2000. Experimental and simulation mapping of the RF field show good agreement, with the ceramic resonator giving a pulse width approximately 25% less than a loop gap resonator of similar inner dimensions. High resolution images, with voxel dimensions less than 50 microm3, have been acquired from fixed zebrafish samples, showing excellent delineation of several fine structures. The 900 MHz probe has an unmatched Q value of 940 and shows Q performance five times better than Alderman-Grant and loop-gap resonators of similar dimensions. High resolution images were acquired of an excised mouse spinal cord (25 microm 3) and an excised rat soleus muscle (20 microm3). The spatial distribution of electromagnetic fields within the human body can be tailored using external dielectric materials. Here, a new material is introduced with high dielectric constant and low background MRI signal. The material is based upon metal titanates, which can be made into geometrically formable suspensions in de-ionized water. The suspension's material properties are

  14. Critical Magnetic Field Determination of Superconducting Materials

    Energy Technology Data Exchange (ETDEWEB)

    Canabal, A.; Tajima, T.; /Los Alamos; Dolgashev, V.A.; Tantawi, S.G.; /SLAC; Yamamoto, T.; /Tsukuba, Natl. Res. Lab. Metrol.

    2011-11-04

    Superconducting RF technology is becoming more and more important. With some recent cavity test results showing close to or even higher than the critical magnetic field of 170-180 mT that had been considered a limit, it is very important to develop a way to correctly measure the critical magnetic field (H{sup RF}{sub c}) of superconductors in the RF regime. Using a 11.4 GHz, 50-MW, <1 {mu}s, pulsed power source and a TE013-like mode copper cavity, we have been measuring critical magnetic fields of superconductors for accelerator cavity applications. This device can eliminate both thermal and field emission effects due to a short pulse and no electric field at the sample surface. A model of the system is presented in this paper along with a discussion of preliminary experimental data.

  15. Lanthanide phosphonates: Synthesis, thermal stability and magnetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Amghouz, Z., E-mail: amghouz.uo@uniovi.es [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Garcia, J.R.; Garcia-Granda, S. [Departamentos de Quimica Fisica y Analitica y Quimica Organica e Inorganica, Universidad de Oviedo - CINN, 33006 Oviedo (Spain); Clearfield, A. [Department of Chemistry, Texas A and M University, College Station, TX 77842-3012 (United States); Rodriguez Fernandez, J.; Pedro, I. de [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Blanco, J.A. [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Report of the complete series of lanthanide 1,4-phenylbis(phosphonate). Black-Right-Pointing-Pointer Synthesis under conventional hydrothermal synthesis or microwave-assisted hydrothermal synthesis. Black-Right-Pointing-Pointer Cation size is the key factor for the structural and particles size variations. Black-Right-Pointing-Pointer Thermal behaviour is characterized by unusual very high thermal stability. - Abstract: Series of novel organic-inorganic hybrids materials based on trivalent lanthanides (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and 1,4-phenylbis(phosphonate) obtained under hydrothermal conditions either by oven heat or microwave irradiation. The anhydrous compounds containing La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho, are isostructural. However, the compounds based on Y, Er, Tm, Yb, and Lu are hydrated and their structures have not yet been solved. The series of compounds are characterized by PXRD, TEM, SEM-EDX and thermal analyses (TG-MS and DSC). TEM study show a variable particles size with a minimum mean-particle size of ca. 30 nm. These compounds exhibit unusual very high thermal stability. The size of particles and the thermal stability are depending on lanthanide(III) cation features. All the investigated materials show paramagnetic behaviour. The magnetic susceptibility data follow a Curie-Weiss laws with paramagnetic effective moments in good agreement with those expected for Ln{sup 3+} free ions.

  16. Introduction to Frustrated Magnetism Materials, Experiments, Theory

    CERN Document Server

    Lacroix, Claudine; Mila, Frédéric

    2011-01-01

    The field of Highly Frustrated Magnetism has developed and expanded considerably over the last 15 years. Originating with canonical geometric frustration of interactions, it today extends over other phenomena with many degrees of freedom, including magneto-elastic couplings, orbital degrees of freedom, dilution effects, and electron doping. It is also demonstrated that the concept of frustration impacts many other fields in physics beyond magnetism. This book represents a state-of-the-art review aimed at a broad audience with tutorial chapters and more topical ones, which encompass solid-state chemistry as well as experimental and theoretical physics.

  17. Correlation Between Domain Behavior and Magnetic Properties of Materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Scott Leib

    2003-05-31

    Correlation between length scales in the field of magnetism has long been a topic of intensive study. The long-term desire is simple: to determine one theory that completely describes the magnetic behavior of matter from an individual atomic particle all the way up to large masses of material. One key piece to this puzzle is connecting the behavior of a material's domains on the nanometer scale with the magnetic properties of an entire large sample or device on the centimeter scale. In the first case study involving the FeSiAl thin films, contrast and spacing of domain patterns are clearly related to microstructure and stress. Case study 2 most clearly demonstrates localized, incoherent domain wall motion switching with field applied along an easy axis for a square hysteresis loop. In case study 3, axis-specific images of the complex Gd-Si-Ge material clearly show the influence of uniaxial anisotropy. Case study 4, the only study with the sole intent of creating domain structures for imaging, also demonstrated in fairly simple terms the effects of increasing stress on domain patterns. In case study 5, it was proven that the width of magnetoresistance loops could be quantitatively predicted using only MFM. When all of the case studies are considered together, a dominating factor seems to be that of anisotropy, both magneticrostaylline and stress induced. Any quantitative bulk measurements heavily reliant on K coefficients, such as the saturation fields for the FeSiAl films, H{sub c} in cases 1, 3, and 5, and the uniaxial character of the Gd{sub 5}(Si{sub 2}Ge{sub 2}), transferred to and from the domain scale quite well. In-situ measurements of domain rotation and switching, could also be strongly correlated with bulk magnetic properties, including coercivity, M{sub s}, and hysteresis loop shape. In most cases, the qualitative nature of the domain structures, when properly considered, matched quite well to what might have been expected from theory and

  18. Synchrotron radiation damage on insulating materials of TRISTAN magnets

    International Nuclear Information System (INIS)

    The shielding design to protect the coils of the bending magnet against synchrotron radiation was performed. The absorbed doses to the magnet components, particularly on the insulating material such as epoxy resin of coil or rubber hoses for water cooling, were measured. The property against radiation exposure was studied. 6 refs., 5 figs

  19. Development of alternating current transmitter of detection system for magnetic material in soil subsurface

    Science.gov (United States)

    Indrasari, Widyaningrum; Djamal, Mitra; Srigutomo, Wahyu; Ramli

    2016-03-01

    Generally, detection system for magnetic material in soil subsurface using electromagnetic induction method consists of two parts, they are transmitter and receiver unit. A transmitter must be able to produce a continuous and stable AC current at a certain frequency, meanwhile receiver should be able to catch the secondary magnetic field of magnetic material in soil subsurface. The aim of this study was to develop a new AC current transmitter of detection system for the magnetic material in soil subsurface. This paper will describe the results of the development of AC current transmitter systems, distance characterization of the sensor detection toward horizontal solenoid positions, and characterization of magnetic material in the soil subsurface. It has successfully made the AC current transmitter system, composed of a sinusoidal signal generator, power amplifier, and a source of AC magnetic field. The output of the generator has a frequency varies: 1 kHz, 2 kHz, 5 kHz, and 10 kHz. We found that the AC current transmitter that has been developed able to work properly up to a frequency of 10 kHz.

  20. Stored energy in fusion magnet materials irradiated at low temperatures

    International Nuclear Information System (INIS)

    During the power cycle of a fusion reactor, the radiation reaching the superconducting magnet system will produce an accumulation of immobile defects in the magnet materials. During a subsequent warm-up cycle of the magnet system, the defects will become mobile and interact to produce new defect configurations as well as some mutual defect annihilations which generate heat-the release of stored energy. This report presents a brief qualitative discussion of the mechanisms for the production and release of stored energy in irradiated materials, a theoretical analysis of the thermal response of irradiated materials, theoretical analysis of the thermal response of irradiated materials during warm-up, and a discussion of the possible impact of stored energy release on fusion magnet operation 20 refs

  1. Magnetic smart material application to adaptive x-ray optics

    Science.gov (United States)

    Ulmer, M. P.; Graham, Michael E.; Vaynman, Semyon; Cao, J.; Takacs, Peter Z.

    2010-09-01

    We discuss a technique of shape modification that can be applied to thin walled ({100-400 micron thickness) electroformed replicated optics or slumped glass optics to improve the near net shape of the mirror as well as the midfrequency ripple. The process involves sputter deposition of a magnetic smart material (MSM) film onto a permanently magnetic material. The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback, locally magnetizes the surface to impart strain where needed. Designs and basic concepts as applied to space borne X-ray optics will be described.

  2. Magnetic materials from co-precipitated ferrite nanoparticles

    International Nuclear Information System (INIS)

    Some of recent technological advances in electronics need very compact magnetic materials. The paper presents the morphology and the magnetic properties of very dense polycrystalline magnetic materials obtained from co-precipitated manganese ferrite nanoparticles. The ferrite nanoparticles, with average diameter in the range of 13-25 nm, were obtained through an original low-cost co-precipitation route from aqueous solution of Mn2+ and Fe3+ ions generated by redox reactions between stoichiometric amounts of MnO2 (piroluzite) and FeSO4.7H2O raw materials. Very dense homogeneous polycrystalline magnetic materials with high square hysteresis loop (Br/Bs = 0.91) and low intrinsic coercivity were obtained using the co-precipitated un-doped manganese ferrite nanoparticles.

  3. FMR measurements in fire ants: evidence of magnetic material

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Darci M.S.; Acosta-Avalos, Daniel; El-Jaick, Lea J.; Cunha, Alexandra D.M.; Malheiros, Maria G.; Wajnberg, Eliane [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Linhares, Marilia P. [Centro de Ciencias do Estado, do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    1998-01-01

    Based on the behavioral and the localization of iron-containing tissue fire ants were examined by EPR for magnetic material. Results suggest the presence of magnetite particles. (author) 12 refs., 1 fig.

  4. Synthesis and characterization of nanorods for magnetic rotational spectroscopy

    Science.gov (United States)

    Aprelev, Pavel; Gu, Yu; Burtovyy, Ruslan; Luzinov, Igor; Kornev, Konstantin G.

    2015-08-01

    Magnetic rotational spectroscopy (MRS) with magnetic nanoprobes is a powerful method for in-situ characterization of minute amounts of complex fluids. In MRS, a uniformly rotating magnetic field rotates magnetic micro- or nano-probes in the liquid and one analyzes the features of the probe rotation to extract rheological parameters of liquids. Magnetic properties of nanoprobes must be well characterized and understood to make results reliable and reproducible. Ni and Co nanorods synthesized by electrochemical template synthesis in alumina membranes are discussed in applications to MRS. We employ alternating gradient field magnetometry, X-ray diffraction, and magnetic force microscopy to evaluate and compare properties of these nanorods and study their performance as the MRS probes. It is shown that nickel nanorods do not seem to violate any assumptions of the MRS rigid dipole theory, while cobalt nanorods do.

  5. Magnetism of carbon-based materials

    OpenAIRE

    Makarova, Tatiana

    2002-01-01

    We present a collection of experimental evidence on UFOs: Unidentified Ferromagnetic Organic structures. Five types of carbon magnets have been obtained experimentally: 1. Chains of interacting radicals 2. Carbonaceous substances with a mixture of sp2 and sp3 coordinated atoms 3. Amorphous carbon structures containing trivalent elements like P, N. B. 4. Nanographite and bulk graphite, nanodiamond, carbon nanofoam 5. Fullerenes.

  6. Method of magnetically separating particulate materials

    NARCIS (Netherlands)

    Rem, P.C.; Zhang, S.

    2000-01-01

    The present invention relates to a method of separating non-ferro metal particles using a rotating magnetic field. According to the invention the particles are surrounded by a fluid restricting the fall-velocity significantly, suitably a fluid having a density of at least 0.1 kg/l. The presence of s

  7. Magnetic Properties of Nanoparticles of Antiferromagnetic Materials

    DEFF Research Database (Denmark)

    Mørup, Steen; Frandsen, Cathrine; Bødker, Franz;

    2003-01-01

    The magnetic properties of antiferromagnetic nanoparticles have been studied by Mossbauer spectroscopy and neutron scattering. Temperature series of Mossbauer spectra of non-interacting, superparamagnetic hematite nanoparticles were fitted by use of the Blume-Tjon relaxation model. It has been fo...

  8. Classification of analysis methods for characterization of magnetic nanoparticle properties

    DEFF Research Database (Denmark)

    Posth, O.; Hansen, Mikkel Fougt; Steinhoff, U.;

    2015-01-01

    The aim of this paper is to provide a roadmap for the standardization of magnetic nanoparticle (MNP) characterization. We have assessed common MNP analysis techniques under various criteria in order to define the methods that can be used as either standard techniques for magnetic particle charact...

  9. Solenopsis ant magnetic material: statistical and seasonal studies

    International Nuclear Information System (INIS)

    In this paper, we quantify the magnetic material amount in Solenopsis ants using ferromagnetic resonance (FMR) at room temperature. We sampled S. interrupta workers from several morphologically indistinguishable castes. Twenty-five oriented samples of each body part of S. interrupta (20 units each) showed that FMR line shapes are reproducible. The relative magnetic material amount was 31 ± 12% (mean ± SD) in the antennae, 27 ± 13% in the head, 21 ± 12% in the thorax and 20 ± 10% in the abdomen. In order to measure variation in the magnetic material from late summer to early winter, ants were collected each month between March and July. The amount of magnetic material was greatest in all four body parts in March and least in all four body parts in June. In addition, S. richteri majors presented more magnetic material than minor workers. Extending these findings to the genera Solenopsis, the reduction in magnetic material found in winter could be explained by our sampling fewer foraging major ants

  10. Magnetic characterization of YBCO-type superconductors

    International Nuclear Information System (INIS)

    This paper reports on ceramic samples of YBCO that have been prepared by mixing powder method. The R vs T dependence has been investigated in applied magnetic field, with the usual four contact d.c. procedure. The measurements have been performed in a gas flow variable temperature cryostat, using helium as coolant. A superconducting magnet provided the magnetic field up 5 Tesla, with the direction perpendicular to the bias current. The temperature dependence of Hc2 was reported and Hc2(0), upper critical field at 0 K, was derived from the slope of the curve

  11. Synthesis and characterization of montmorillonite clay intercalated with molecular magnetic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Marcel G.; Martins, Daniel O.T.A.; Carvalho, Beatriz L.C. de [Instituto de Química, Universidade Federal Fluminense, Niterói, RJ 24.020–150 (Brazil); Mercante, Luiza A. [Laboratório Nacional de Nanotecnologia para o Agronegócio (LNNA), Embrapa Instrumentação, São Carlos, SP 13560 970 (Brazil); Soriano, Stéphane [Instituto de Física, Universidade Federal Fluminense, Niterói, RJ 24.210 346 (Brazil); Andruh, Marius [Inorganic Chemistry Laboratory, Faculty of Chemistry, University of Bucharest, Str. Dumbrava Rosie nr. 23, Bucharest (Romania); Vieira, Méri D., E-mail: gqimeri@vm.uff.br [Instituto de Química, Universidade Federal Fluminense, Niterói, RJ 24.020–150 (Brazil); Vaz, Maria G.F., E-mail: mariavaz@vm.uff.br [Instituto de Química, Universidade Federal Fluminense, Niterói, RJ 24.020–150 (Brazil)

    2015-08-15

    In this work montmorillonite (MMT) clay, whose matrix was modified with an ammonium salt (hexadecyltrimethylammonium bromide – CTAB), was employed as an inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange: a nitronyl nitroxide derivative 2-[4-(N-ethyl)-pyridinium]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (p-EtRad{sup +}) and two binuclear coordination compounds, [Ni(valpn)Ln]{sup 3+}, where H{sub 2}valpn stands for 1,3-propanediyl-bis(2-iminomethylene-6-methoxy-phenol), and Ln=Gd{sup III}; Dy{sup III}. The pristine MMT and the intercalated materials were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and magnetic measurements. The X-ray diffraction data analysis showed an increase of the interlamellar space of the intercalated MMT, indicating the intercalation of the magnetic compounds. Furthermore, the magnetic properties of the hybrid compounds were investigated, showing similar behavior as the pure magnetic guest species. - Graphical abstract: Montmorillonite clay was employed as inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange - Highlights: • Montmorillonite was employed as a host material. • Three molecular magnetic compounds were intercalated through ion exchange. • The compounds were successful intercalated maintaining the layered structure. • The hybrid materials exhibited similar magnetic behavior as the pure magnetic guest.

  12. Synthesis and characterization of montmorillonite clay intercalated with molecular magnetic compounds

    International Nuclear Information System (INIS)

    In this work montmorillonite (MMT) clay, whose matrix was modified with an ammonium salt (hexadecyltrimethylammonium bromide – CTAB), was employed as an inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange: a nitronyl nitroxide derivative 2-[4-(N-ethyl)-pyridinium]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (p-EtRad+) and two binuclear coordination compounds, [Ni(valpn)Ln]3+, where H2valpn stands for 1,3-propanediyl-bis(2-iminomethylene-6-methoxy-phenol), and Ln=GdIII; DyIII. The pristine MMT and the intercalated materials were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and magnetic measurements. The X-ray diffraction data analysis showed an increase of the interlamellar space of the intercalated MMT, indicating the intercalation of the magnetic compounds. Furthermore, the magnetic properties of the hybrid compounds were investigated, showing similar behavior as the pure magnetic guest species. - Graphical abstract: Montmorillonite clay was employed as inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange - Highlights: • Montmorillonite was employed as a host material. • Three molecular magnetic compounds were intercalated through ion exchange. • The compounds were successful intercalated maintaining the layered structure. • The hybrid materials exhibited similar magnetic behavior as the pure magnetic guest

  13. Digital lock-in detection of site-specific magnetism in magnetic materials

    Science.gov (United States)

    Haskel, Daniel; Lang, Jonathan C.; Srajer, George

    2008-07-22

    The polarization and diffraction characteristics of x-rays incident upon a magnetic material are manipulated to provide a desired magnetic sensitivity in the material. The contrast in diffracted intensity of opposite helicities of circularly polarized x-rays is measured to permit separation of magnetic signals by element type and by atomic environment. This allows for the direct probing of magnetic signals from elements of the same species in nonequivalent atomic environments to better understand the behavior and characteristics of permanent magnetic materials. By using known crystallographic information together with manipulation of the polarization of x-rays having energies tuned near element-specific electronic excitations and by detecting and comparing the incident and diffracted photons at the same frequency, more accurate magnetic measurements can be made over shorter observation periods.

  14. Nanomagnetism and spintronics fabrication, materials, characterization and applications

    CERN Document Server

    Nasirpouri, Farzad

    2010-01-01

    Nanomagnetism and spintronics are two close subfields of nanoscience, explaining the effect of substantial magnetic properties of matter when the materials fabrication is realized at a comparable length size. Nanomagnetism deals with the magnetic phenomena specific to the structures having dimensions in the submicron range. The fact that the electronic transport properties of materials are dependent on the magnetic properties' artificial nanostructures, i.e., giant magnetoresistance (GMR) or tunneling magnetoresistance (TMR), has revolutionized spintronics science and technology. This book exp

  15. Surface spectroscopic characterization of titanium implant materials

    Science.gov (United States)

    Lausmaa, Jukka; Kasemo, Bengt; Mattsson, Håkan

    1990-04-01

    Titanium is one of the most commonly used biomaterials for dental and orthopedic applications. Its excellent tissue compatibility is mainly due to the properties of the stable oxide layer which is present on the surface. This paper reports a detailed spectroscopic characterization of the surface composition of non-alloyed Ti implant materials, prepared according to procedures commonly used in clinical practice (machining, ultrasonic cleaning and sterilization). The main methods of characterization are XPS and AES, and complementary information is obtained by SIMS, EDX and NMA (nuclear microanalysis). The surface of the implants is found to consist of a thin surface oxide which is covered by a carbon-dominated contamination layer. By comparison with reference spectra from single crystal TiO 2 (rutile) the composition of the surface oxide is shown to be mainly TiO 2, with minor amounts of suboxides and TiN x. The thickness of the surface oxides is 2-6 nm, depending on the method of sterilization. The surface contamination layer is found to vary considerably from sample to sample and consists of mainly hydrocarbons with trace amounts of Ca, N, S, P, Cl. Some differences in surface composition between directly prepared surfaces, and some possible contamination sources, are identified and discussed shortly.

  16. Magnetic materials in Japan research, applications and potential

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This, the third report in Elsevier's Materials Technology in Japan series, concentrates on magnetic materials as a topic gaining worldwide attention, and each chapter looks not only at current research, but also describes the technology as it is being applied and its future potential. Magnetic-related research is the second largest field of research in Japan after semiconductors, with the estimated number of researchers and engineers engaged in magnetics-related activities currently at 20,000. This research report serves as both a review of

  17. Characterizing the magnetic fields of the first tau Sco analogues

    CERN Document Server

    Kochukhov, V Petit O; Marcolino, W L F; Wade, G A; Ignace, R

    2011-01-01

    The B0.2 V magnetic star tau Sco stands out from the larger population of massive OB stars due to its high X-ray activity, peculiar wind diagnostics and complex magnetic field. Recently, Petit et al. 2011 presented the discovery of the first two tau Sco analogues -- HD 66665 and HD 63425, identified by the striking similarity of their UV spectra to that of tau Sco. ESPaDOnS and Narval spectropolarimetric observations were obtained by the Magnetism in Massive Stars CFHT and TBL Large Programs, in order to characterize the stellar and magnetic properties of these stars. A magnetic field of similar surface strength was found on both stars, reinforcing the connection between the presence of a magnetic field and wind peculiarities. We present additional phase-resolved observations secured by the MiMeS collaboration for HD 66665 in order to measure its magnetic geometry, and correlate that geometry with diagnostics of mass-loss.

  18. Characterizing the magnetic fields of the first τ Sco analogues

    Science.gov (United States)

    Petit, V.; Kochukhov, O.; Massa, D. L.; Marcolino, W. L. F.; Wade, G. A.; Ignace, R.

    2012-05-01

    The B0.2 V magnetic star τ Sco stands out from the larger population of massive OB stars due to its high X-ray activity, peculiar wind diagnostics and complex magnetic field. Recently, Petit et al. [1] presented the discovery of the first two τ Sco analogues - HD66665 and HD63425, identified by the striking similarity of their UV spectra to that of τ Sco. ESPaDOnS and Narval spectropolarimetric observations were obtained by the Magnetism in Massive Stars CFHT and TBL Large Programs, in order to characterize the stellar and magnetic properties of these stars. A magnetic field of similar surface strength was found on both stars, reinforcing the connection between the presence of a magnetic field and wind peculiarities. We present additional phaseresolved observations secured by the MiMeS collaboration for HD66665 in order to measure its magnetic geometry, and correlate that geometry with diagnostics of mass-loss.

  19. Growth and characterization of bulk superconductor material

    CERN Document Server

    Chen, Dapeng; Maljuk, Andrey; Zhou, Fang

    2016-01-01

    This book focuses on recently developed crystal growth techniques to grow large and high quality superconducting single crystals. The techniques applied are traveling solvent floating zone (TSFZ) with infrared image furnace, Bridgeman, solution/flux and top seeded solution growth (TSSG) methods. The materials range from cuprates, cobaltates to pnictides including La2CuO4-based (LCO), YBa2Cu3O7-d (YBCO), Bi2Sr2Can−1CunO2n+4+δ (n=1,2,3) (BSCCO) to NaxCoO2. The modified Bridgman “cold finger” method is devoted to the pnictide system with the best quality (transition width DTc~0.5 K) with highest Tc~38.5 K of Ba0.68K0.32Fe2A2. The book presents various iron-based superconductors with different structures, such as 1111, 122, 111, 11 and 42622,10-3-8. Detailed single crystal growth methods (fluxes, Bridgman, floating zone), the associated procedures and their impact to crystal size and quality are presented. The book also describes the influence of doping on the structure and the electric, magnetic, and supe...

  20. Nondestructive characterization of UHMWPE armor materials

    International Nuclear Information System (INIS)

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  1. Nondestructive characterization of UHMWPE armor materials

    Energy Technology Data Exchange (ETDEWEB)

    Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011 (United States)

    2012-05-17

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  2. Nondestructive characterization of UHMWPE armor materials

    Science.gov (United States)

    Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David

    2012-05-01

    Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

  3. Material characterization of ancient Indian copper

    Indian Academy of Sciences (India)

    A Srivastava; R Balasubramaniam

    2003-10-01

    A chalcolithic (2350–1800 BC) copper chisel from Balathal has been characterized by X-ray diffraction, microstructural and electrochemical methods. The surface patina was composed of sulfates and oxysulfates in the outer layers while the inner layers were rich in copper oxides. The chisel exhibited smaller grain sizes near two of the surfaces while the structure in the interior was equiaxed. The deformed grains and inclusions near the surfaces and variation in the microhardness of the sample from different faces proved that the copper chisel was processed by cold deformation after initial casting of the square cross-section chisel. The electrochemical behaviour of chalcolithic Cu has been compared with that of a modern Cu sample by potentiodynamic polarization studies. The corrosion rate of chalcolithic Cu in aerated 3.5% NaCl solution was only marginally higher than that of modern Cu. The higher rate of corrosion has been attributed to the presence of second phase sulfide inclusions. The excellent condition of preservation of the 3800-year-old copper object, with no indications of stress corrosion cracking, suggests that pure copper or copper-based materials can be seriously considered as candidate canister materials for long-term underground storage of nuclear wastes in underground repositories.

  4. Bi-magnetic microwires: a novel family of materials with controlled magnetic behavior

    International Nuclear Information System (INIS)

    A novel technique involving combined sputtering and electroplating procedures has been recently developed to deposit metallic (magnetic or not) nano and microlayer tubes onto glass-coated amorphous magnetic microwires to enable the tailoring of their magnetic behavior. Here, after introducing the general aspects of that technique, we present the latest results on a new family of two-phase magnetic samples: bi-magnetic multilayer microwires. They consist of a magnetically soft nucleus (typically a Fe or Co base amorphous microwire, coated by Pyrex layer) onto which a 30 nm thick Au layer is first sputtered followed by the electroplating of a harder microlayer, namely Co x Ni(1-x) layer, with x controlled by the current density during electrodeposition whose micrometric thickness is also controlled by plating time. The hysteresis loops present a two-step reversal process typical of two-phase magnetic material. The magnetization reversal of the soft nucleus and the harder layer takes place at around 1 Oe and up to about 200 Oe, respectively. The presence of sputtered and electroplated layers induces significant stresses in the soft magnetic nucleus that modify its magnetization easy axis. This technique allowing us the tailoring of the magnetic behavior of multilayer magnetic microwires opens new possibilities for applying these novel materials as sensing elements in various devices

  5. Optical Material Characterization Using Microdisk Cavities

    Science.gov (United States)

    Michael, Christopher P.

    Since Jack Kilby recorded his "Monolithic Idea" for integrated circuits in 1958, microelectronics companies have invested billions of dollars in developing the silicon material system to increase performance and reduce cost. For decades, the industry has made Moore's Law, concerning cost and transistor density, a self-fulfilling prophecy by integrating technical and material requirements vertically down their supply chains and horizontally across competitors in the market. At recent technology nodes, the unacceptable scaling behavior of copper interconnects has become a major design constraint by increasing latency and power consumption---more than 50% of the power consumed by high speed processors is dissipated by intrachip communications. Optical networks at the chip scale are a potential low-power high-bandwidth replacement for conventional global interconnects, but the lack of efficient on-chip optical sources has remained an outstanding problem despite significant advances in silicon optoelectronics. Many material systems are being researched, but there is no ideal candidate even though the established infrastructure strongly favors a CMOS-compatible solution. This thesis focuses on assessing the optical properties of materials using microdisk cavities with the intention to advance processing techniques and materials relevant to silicon photonics. Low-loss microdisk resonators are chosen because of their simplicity and long optical path lengths. A localized photonic probe is developed and characterized that employs a tapered optical-fiber waveguide, and it is utilized in practical demonstrations to test tightly arranged devices and to help prototype new fabrication methods. A case study in AlxGa1-xAs illustrates how the optical scattering and absorption losses can be obtained from the cavity-waveguide transmission. Finally, single-crystal Er2O3 epitaxially grown on silicon is analyzed in detail as a potential CMOS-compatable gain medium due to its high Er3

  6. A MHO-based magnetic hysteresis model for amorphous materials

    International Nuclear Information System (INIS)

    A magnetic hysteretic operator (MHO) is proposed in this paper. Based on the constructed MHO, the input space of neural networks is expanded from one-dimension to two-dimension using the expanded space method so that the one-to-multiple mapping of magnetic hysteresis is transformed into one-to-one mapping. Based on the expanded input space, a neural network is employed to identify magnetic hysteresis. The result of an experimental example suggests the proposed approach is effective. - Highlights: • The expanded space method is improved. • A magnetic hysteretic operator (MHO) for magnetic hysteresis is presented. • A MHO-based magnetic hysteresis model for amorphous materials is obtained

  7. Synthesis and characterization of magnetic nanoparticles

    Institute of Scientific and Technical Information of China (English)

    邱星屏

    2000-01-01

    Magnetic nanoparticles with average diameter in the range of 6.4-8.3 nm have been synthesized by a chemical co-precipi-tation of Fe(Ⅱ) and Fe(Ⅲ) salts in 1.5 M NH4OH solution.The size of the magenetic particles is dependent on both temperature and the ionic strength of the iron ion solutions. The magnetic particles formed at higher temperature or lower ionic strength were slightly larger than those formed at lower temperature or higher ionic strength respectively. In spite of the different reaction co nditions, all the resultant nanopar ticles are nearly spherical and have a similar crystalline structure. At300 K, such prepared nanoparticles are superparamagnetic. The saturation magnetizations for 7.8 and 6.4 nm particles are 71 and 63 emu/g respectively, which are only -20-30% less than the saturation magnetization (90 emu/g) of bulk Fe3O4. Our results indicated that a control of the reaction conditions could be used to tailor the size of magnetic nanoparticles in free precipita tion.

  8. Magnetic hyaluronate hydrogels: preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tóth, Ildikó Y., E-mail: Ildiko.Toth@chem.u-szeged.hu; Veress, Gábor; Szekeres, Márta; Illés, Erzsébet; Tombácz, Etelka, E-mail: tombacz@chem.u-szeged.hu

    2015-04-15

    A novel soft way of hyaluronate (HyA) based magnetic hydrogel preparation was revealed. Magnetite nanoparticles (MNPs) were prepared by co-precipitation. Since the naked MNPs cannot be dispersed homogenously in HyA-gel, their surface was modified with natural and biocompatible chondroitin-sulfate-A (CSA) to obtain CSA-coated MNPs (CSA@MNPs). The aggregation state of MNPs and that loaded with increasing amount of CSA up to 1 mmol/g was measured by dynamic light scattering at pH~6. Only CSA@MNP with ≥0.2 mmol/g CSA content was suitable for magnetic HyA-gel preparation. Rheological studies showed that the presence of CSA@MNP with up to 2 g/L did not affect the hydrogel's rheological behavior significantly. The results suggest that the HyA-based magnetic hydrogels may be promising formulations for future biomedical applications, e.g. as intra-articular injections in the treatment of osteoarthritis. - Highlights: • Novel hyaluronate(HyA)-based biocompatible magnetic hydrogels were prepared. • Chondroitin-sulfate-A coating is needed to disperse magnetite particles in HyA-gel. • Rheological behavior of hydrogels was independent of the magnetite content (<2 g/L). • Gels remained in stable and homogeneously dispersed state even after 90 days storage. • Magnetic HyA-gels are promising candidates for use as intra-articular injection.

  9. Magnetic microrheometer for in situ characterization of coating viscosity.

    Science.gov (United States)

    Song, Jin-Oh; Henry, Robert M; Jacobs, Ryan M; Francis, Lorraine F

    2010-09-01

    A magnetic microrheometer has been designed to characterize the local viscosity of liquid-applied coatings in situ during solidification. The apparatus includes NdFeB magnets mounted on computer-controlled micropositioners for the manipulation of ∼1 μm diameter superparamagnetic particles in the coating. Magnetic field gradients at 20-70 T/m are generated by changing magnet size and the gap distance between the magnets. A specimen stage located between two magnets is outfitted with a heater and channels to control process conditions (temperature and air flow), and a digital optical microscope lens above the stage is used to monitor the probe particle position. Validation studies with glycerol and polyimide precursor solution showed that microrheometry results match traditional bulk rheometry within an error of 5%. The viscosities of polyvinyl alcohol (PVA) solution and polyimide precursor solution coatings were measured at different shear rates (0.01-5 s(-1)) by adjusting the magnetic field gradient. The effect of proximity to the substrate on the particle motion was characterized and compared with theoretical predictions. The magnetic microrheometer was used to characterize the time-viscosity profile of PVA coatings during drying at several temperatures. The viscosity range measured by the apparatus was 0.1-20 Pa s during drying of coatings at temperatures between room temperature and 80 °C. PMID:20886990

  10. Proton radiography as a means of material characterization

    International Nuclear Information System (INIS)

    We describe how protons with energies of 800 MeV or greater can be used as radiographic probes for material characterization. A feature which distinguishes protons from x-rays is their charge, which results in multiple Coulomb scattering effects in proton radiographs. Magnetic lensing can ameliorate these effects and even allow mixed substances to be disentangled. We illustrate some of these effects using 800 MeV protons radiographs of a composite step wedge composed of Aluminum, Foam, and Graphite. We discuss how proton radiographs must be manipulated in order to use standard tomographic reconstruction algorithms. We conclude with a brief description of an upcoming experiment, which will be performed at Brookhaven National Laboratory at 25 GeV

  11. Carnot cycle for magnetic materials: The role of hysteresis

    International Nuclear Information System (INIS)

    The role of hysteresis in a refrigeration thermodynamic cycle involving ferromagnetic materials is discussed. A model allowing to calculate magnetization, entropy and entropy production in systems with hysteresis is used to compute a non-ideal Carnot cycle performed on a ferromagnetic material

  12. Experimental Tape Casting of Adjacently Graded Materials for Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Bulatova, Regina

    graded thin films. The motivation to create such adjacently segmented structures stemmed from a search of material and a materials design alternative to the expensive rare earth element gadolinium which is widely used as a magnetic regenerator in the emerging magnetic refrigeration technology....... Conventional tape casting involves the preparation of specially formulated slurry, which is cast by a blade to a thin flat tape, then dried into flexible so-called green solid tape and can be subsequently sintered into a hard ceramic material. The principal difference and, at the same time, a challenge...

  13. Multimaterial magnetically assisted 3D printing of composite materials

    Science.gov (United States)

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

    2015-10-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

  14. Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient.

    Science.gov (United States)

    Gutfleisch, Oliver; Willard, Matthew A; Brück, Ekkes; Chen, Christina H; Sankar, S G; Liu, J Ping

    2011-02-15

    A new energy paradigm, consisting of greater reliance on renewable energy sources and increased concern for energy efficiency in the total energy lifecycle, has accelerated research into energy-related technologies. Due to their ubiquity, magnetic materials play an important role in improving the efficiency and performance of devices in electric power generation, conditioning, conversion, transportation, and other energy-use sectors of the economy. This review focuses on the state-of-the-art hard and soft magnets and magnetocaloric materials, with an emphasis on their optimization for energy applications. Specifically, the impact of hard magnets on electric motor and transportation technologies, of soft magnetic materials on electricity generation and conversion technologies, and of magnetocaloric materials for refrigeration technologies, are discussed. The synthesis, characterization, and property evaluation of the materials, with an emphasis on structure-property relationships, are discussed in the context of their respective markets, as well as their potential impact on energy efficiency. Finally, considering future bottlenecks in raw materials, options for the recycling of rare-earth intermetallics for hard magnets will be discussed. PMID:21294168

  15. Nuclear magnetic resonance of randomly diluted magnetic materials

    International Nuclear Information System (INIS)

    The temperature dependence of the nuclear relaxation rates and line shapes of the FO resonance in the diluted antiferromagnet Fex Zn1-x F2 and Mnx Zn1-x F2 are studied over a large temperature range TN 1) of the FO nuclei, which are not transfer hyperfine coupled to the Fe (or Mn) spins, have been measured and calculated as a function of the concentration x. Good agreement with experiment is found for the theoretical results, which have been obtained in the range 0.1 ≤ x ≤ 0.8. The temperature dependence of 1/T1 for TN1 data near TN was used to study Random Field Effects on the critical behavior of Mn.65 Zn.35 F2, for fields applied parallel and perpendicular to the easy (C) axis. It was found that the transition temperature TN depressed substantially with field only for Ho || C. The experimental results are in general accord with the theory for Random Field Effects in disordered, anisotropic antiferromagnets. The critical divergence of the inhomogeneously broadened FO NMR was studied in Fe.6 Zn.4 F2 above TN. The experimental results agree with Heller's calculation of the NMR line broadening by Random Field Effects. With Ho || C the line shape changes from Gaussian towards Lozentzian for t -2 and below TN its line width increase qualitatively following the increase in the sublattice magnetization. (author)

  16. Opportunities and challenges of 2D magnetic van der Waals materials: magnetic graphene?

    Science.gov (United States)

    Park, Je-Geun

    2016-08-01

    There has been a huge increase of interests in two-dimensional van der Waals materials over the past ten years or so with the conspicuous absence of one particular class of materials: magnetic van der Waals systems. In this Viewpoint, we point it out and illustrate how we might be able to benefit from exploring these so-far neglected materials.

  17. High temperature magnetic balance for education : A basic investigation of the teaching materials for the material science education

    OpenAIRE

    Tokunaga, Toshihiko; Kasagi, Teruhiko; Maehara, Toshinobu; Tsutaoka, Takanori

    2005-01-01

    Magnetic properties of the several magnetic alloys and compounds were studied for the development of the teaching materials in the material science education by using a hand made high temperature magnetic balance. Magnetism treated were ferro-, para- and antiferromagnetism and magnetic phase transitions among them. Together with the data of resistivity, the possibility of the teaching materials concerning the material scie.nce education will he discussed.

  18. Magnetic switch structure and method employing superconductive material

    International Nuclear Information System (INIS)

    Electrical switch structure is described comprising a magnetizable core, an electrical switch circuit which includes an electrically conductive winding and a source of electrical energy, the electrically conductive winding encompassing a portion of the magnetizable core, whereby electrical current flowing in the electrically conductive winding creates a first magnetic flux in the magnetizable core, a body of superconductive material encompassing a portion of the magnetizable core, the body of superconductive material having a superconductive state and a resistive state, the body of superconductive material including a primary current conduction plane, the electrical switch structure including means for conducting electrical current through the body of superconductive material in a direction angular with respect to the primary current conduction plane, whereby the body of superconductive material is placed in a resistive state when electrical current flows through the body of superconductive material in a direction angular with respect to the primary current conduction plane, whereby when the body of superconductive material is in its superconductive state current is induced therein by the first magnetic flux and whereby current flow in the body of superconductive material creates a second magnetic flux within the magnetizable core and the second magnetic flux cancels the first magnetic flux, whereby reactance within the electrically conductive winding is negligible and current flows through the electrically conductive winding, and whereby the electrical switch circuit is in its ''on'' state, and whereby when the body of superconductive material is in its resistive state no significant current is generated in the body of superconductive material and reactance within the electrically conductive winding prevents current flow in the electrical switch circuit and whereby the electrical switch circuit is in its off state

  19. Electroplating and characterization of cobalt-nickel-iron and nickel-iron for magnetic microsystems applications

    DEFF Research Database (Denmark)

    Rasmussen, Frank Engel; Ravnkilde, Jan Tue; Tang, Peter Torben;

    2001-01-01

    The magnetic properties of pulse reverse (PR) electroplated CoNiFe and DC electroplated NiTe are presented. CoNiFe is a very promising material for magnetic microsystems due to the possibility of achieving a high saturation flux density (B-s) and a low coercivity (H-c). A new bath formulation has...... been developed, which by means of PR electroplating makes it possible to deposit high B-s CoNiFe with a low residual stress level. The magnetic properties have been determined using a new simple measurement setup that allows for wafer level characterization. The results have been validated by...

  20. Eddy current characterization of magnetic treatment of nickel 200

    Science.gov (United States)

    Chern, E. J.

    1993-01-01

    Eddy current methods have been applied to characterize the effect of magnetic treatments on component service-life extension. Coil impedance measurements were acquired and analyzed on nickel 200 specimens that have been subjected to many mechanical and magnetic engineering processes: annealing, applied strain, magnetic field, shot peening, and magnetic field after peening. Experimental results have demonstrated a functional relationship between coil impedance, resistance and reactance, and specimens subjected to various engineering processes. It has shown that magnetic treatment does induce changes in electromagnetic properties of nickel 200 that then exhibit evidence of stress relief. However, further fundamental studies are necessary for a thorough understanding of the exact mechanism of the magnetic field processing effect on machine-tool service life.

  1. Left-handed materials in metallic magnetic granular composites

    OpenAIRE

    Chui, S. T.; Lin, Z. F.; Hu, L. -B.

    2003-01-01

    There is recently interests in the ``left-handed '' materials. In these materials the direction of the wave vector of electromagnetic radiation is opposite to the direction of the energy flow. We present simple arguments that suggests that magnetic composites can also be left-handed materials. However, the physics involved seems to be different from the original argument. In our argument, the imaginary part of the dielectric constant is much larger than the real part, opposite to the original...

  2. Pulsed laser deposition and characterization of Alnico5 magnetic films

    International Nuclear Information System (INIS)

    Alnico5 films were deposited by pulsed laser deposition on glass substrate at room temperature under a vacuum ∼10−3 Torr in the absence and in the presence of 500 Oe external transverse magnetic field applied on the plasma plume during film deposition. For this purpose, Nd:YAG laser was employed to ablate the Alnico5 target. The ablated material was deposited on glass substrate placed at a distance of 2 cm from the target. The structural and magnetic properties of the film were analyzed by X-ray diffraction, atomic force microscope, and vibrating sample magnetometer. X-ray diffraction patterns showed that the Alnico5 films were amorphous in nature. Atomic force microscopy revealed that the Alnico5 film deposited in absence of external magnetic field has larger root-mean-square roughness value (60.2 nm) than the magnetically deposited film (42.9 nm). Vibrating sample magnetometer measurements showed that the in-plane saturation magnetization of Alnico5 film deposited in the presence of external magnetic field increases by 32% as compared to that for the film deposited in the absence of external magnetic field. However, the out-of-plane saturation magnetization was almost independent of the external magnetic field. In magnetically deposited film, there is in-plane anisotropy parallel to the applied external magnetic field.

  3. EDITORIAL: (Nano)characterization of semiconductor materials and structures (Nano)characterization of semiconductor materials and structures

    Science.gov (United States)

    Bonanni, Alberta

    2011-06-01

    The latest impressive advancements in the epitaxial fabrication of semiconductors and in the refinement of characterization techniques have the potential to allow insight into the deep relation between materials' structural properties and their physical and chemical functionalities. Furthermore, while the comprehensive (nano)characterization of semiconductor materials and structures is becoming more and more necessary, a compendium of the currently available techniques is lacking. We are positive that an overview of the hurdles related to the specific methods, often leading to deceptive interpretations, will be most informative for the broad community working on semiconductors, and will help in shining some light onto a plethora of controversial reports found in the literature. From this perspective, with this special issue we address and highlight the challenges and misinterpretations related to complementary local (nanoscale) and more global experimental methods for the characterization of semiconductors. The six topical reviews and the three invited papers by leading experts in the specific fields collected in here are intended to provide the required broad overview on the possibilities of actual (nano)characterization methods, from the microscopy of single quantum structures, over the synchrotron-based absorption and diffraction of nano-objects, to the contentious detection of tiny magnetic signals by quantum interference and resonance techniques. We are grateful to all the authors for their valuable contributions. Moreover, I would like to thank the Editorial Board of the journal for supporting the realization of this special issue and for inviting me to serve as Guest Editor. We greatly appreciate the work of the reviewers, of the editorial staff of Semiconductor Science and Technology and of IOP Publishing. In particular, the efforts of Alice Malhador in coordinating this special issue are acknowledged.

  4. Structure and magnetism in novel group IV element-based magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Frank [Univ. of North Carolina, Chapel Hill, NC (United States)

    2013-08-14

    The project is to investigate structure, magnetism and spin dependent states of novel group IV element-based magnetic thin films and heterostructures as a function of composition and epitaxial constraints. The materials systems of interest are Si-compatible epitaxial films and heterostructures of Si/Ge-based magnetic ternary alloys grown by non-equilibrium molecular beam epitaxy (MBE) techniques, specifically doped magnetic semiconductors (DMS) and half-metallic Heusler alloys. Systematic structural, chemical, magnetic, and electrical measurements are carried out, using x-ray microbeam techniques, magnetotunneling spectroscopy and microscopy, and magnetotransport. The work is aimed at elucidating the nature and interplay between structure, chemical order, magnetism, and spin-dependent states in these novel materials, at developing materials and techniques to realize and control fully spin polarized states, and at exploring fundamental processes that stabilize the epitaxial magnetic nanostructures and control the electronic and magnetic states in these complex materials. Combinatorial approach provides the means for the systematic studies, and the complex nature of the work necessitates this approach.

  5. Synthesis, characterization and magnetic behavior of Co/MCM-41 nano-composites

    Science.gov (United States)

    Cuello, N.; Elías, V.; Crivello, M.; Oliva, M.; Eimer, G.

    2013-09-01

    Synthesis, structure and magnetic properties of Co/MCM-41 as magnetic nano-composites have been investigated. Mesoporous materials with different degrees of metal loading were prepared by wet impregnation and characterized by ICP, XRD, N2 adsorption, UV-vis DRS, TPR and EPMA-EDS. Cobalt oxide clusters and Co3O4 nano-particles could be confined inside the mesopores of MCM-41, being this fact favored by the Co loading increasing. In addition, larger crystals of Co3O4 detectable by XRD also grow on the surface when the Co loading is enhanced. The magnetic characterization was performed in a SQUID magnetometer using a maximum magnetic applied field µ0Ha=1 T. While the samples with the higher Co loadings showed a behavior typically paramagnetic, a superparamagnetic contribution is more notorious for lower loadings, suggesting high Co species dispersion.

  6. High Temperature Materials Characterization and Advanced Materials Development

    International Nuclear Information System (INIS)

    The project has been carried out for 2 years in stage III in order to achieve the final goals of performance verification of the developed materials, after successful development of the advanced high temperature material technologies for 3 years in Stage II. The mechanical and thermal properties of the advanced materials, which were developed during Stage II, were evaluated at high temperatures, and the modification of the advanced materials were performed. Moreover, a database management system was established using user-friendly knowledge-base scheme to complete the integrated-information material database in KAERI material division

  7. Evaluation and Characterization of Magnets and Capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Seiber, L.E.; Cunningham, J.P.; Golik, S.S. (ORISE); Armstrong, G. (Maverick Systems)

    2006-10-15

    Advanced vehicle, fuel cell, hybrid electric vehicle (HEV), and plug in hybrid research and development is conducted by the U.S. Department of Energy (DOE) through its FreedomCAR and Vehicle Technologies (FCVT) program. The mission of this program is to develop more energy efficient and environmentally safe highway transportation technologies. Program activities include research, development, testing, technology validation, and technology transfer. These activities are done at the system and component levels. This report will discuss component level testing of prototype capacitors and magnets. As capacitor and magnet technologies mature, it is important to ascertain the limitations of these new technologies by subjecting the components to standardized tests to evaluate their capabilities. Test results will assist in the determination of their ability to provide improvements in power electronics and motor designs to meet the FCVT goals.

  8. Synthesis and characterization of magnetic palygorskite nanoparticles and their application on methylene blue remotion from water

    Energy Technology Data Exchange (ETDEWEB)

    Middea, Antonieta, E-mail: amiddea@cetem.gov.br [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Spinelli, Luciana S., E-mail: spinelli@ima.ufrj.br [Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Souza, Fernando G. [Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Neumann, Reiner; Gomes, Otavio da F.M. [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Federal University of Rio de Janeiro, National Museum of Brazil, Postgraduate Program in Geosciences, Av. Quinta da Boa Vista, S/N Bairro Imperial de São Cristóvão, Rio de Janeiro 20940040 (Brazil); Fernandes, Thais L.A.P.; Lima, Luiz C. de [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Barthem, Vitoria M.T.S. [Federal University of Rio de Janeiro, Physics Institute, Av. Athos da Silveira Ramos, 149, Cidade Universitária, Rio de Janeiro 21941972 (Brazil); Carvalho, Fernanda V. de [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil)

    2015-08-15

    Highlights: • Nanopalygorskites’ surface modification was confirmed by characterization. • The magnetism of nanoparticles was characterized by different techniques. • Methylene blue was easily removed using the magnetic nanopalygorskites. - Abstract: Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10{sup −4} Am{sup 2}/kg to about 20 Am{sup 2}/kg. A weight loss was also observed around 277 °C–339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite.

  9. Characterization of material for civil engineering

    OpenAIRE

    Cappelletto, Elisa

    2014-01-01

    Materials are the heart of engineering, which can be defined as the creative and rational use of materials for practical purposes. Materials have had an essential role in the development of civil engineering: from the beginning of human evolution, man has used many different materials to build houses, bridges, roads and countless other structures to make his life easier. Ancient populations used the raw materials at their disposal, such as stone, clay and timber. Over the centuries, the searc...

  10. Versatile magnetometer assembly for characterizing magnetic properties of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, J. F. D. F.; Bruno, A. C.; Louro, S. R. W. [Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro 22451-900 (Brazil)

    2015-10-15

    We constructed a versatile magnetometer assembly for characterizing iron oxide nanoparticles. The magnetometer can be operated at room temperature or inside a cryocooler at temperatures as low as 6 K. The magnetometer’s sensor can be easily exchanged and different detection electronics can be used. We tested the assembly with a non-cryogenic commercial Hall sensor and a benchtop multimeter in a four-wire resistance measurement scheme. A magnetic moment sensitivity of 8.5 × 10{sup −8} Am{sup 2} was obtained with this configuration. To illustrate the capability of the assembly, we synthesized iron oxide nanoparticles coated with different amounts of a triblock copolymer, Pluronic F-127, and characterized their magnetic properties. We determined that the polymer coating does not affect the magnetization of the particles at room temperature and demonstrates that it is possible to estimate the average size of coating layers from measurements of the magnetic field of the sample.

  11. Versatile magnetometer assembly for characterizing magnetic properties of nanoparticles

    International Nuclear Information System (INIS)

    We constructed a versatile magnetometer assembly for characterizing iron oxide nanoparticles. The magnetometer can be operated at room temperature or inside a cryocooler at temperatures as low as 6 K. The magnetometer’s sensor can be easily exchanged and different detection electronics can be used. We tested the assembly with a non-cryogenic commercial Hall sensor and a benchtop multimeter in a four-wire resistance measurement scheme. A magnetic moment sensitivity of 8.5 × 10−8 Am2 was obtained with this configuration. To illustrate the capability of the assembly, we synthesized iron oxide nanoparticles coated with different amounts of a triblock copolymer, Pluronic F-127, and characterized their magnetic properties. We determined that the polymer coating does not affect the magnetization of the particles at room temperature and demonstrates that it is possible to estimate the average size of coating layers from measurements of the magnetic field of the sample

  12. Design of a Virtual Laboratory for Analyzing Nanoscale Magnetic Materials

    Directory of Open Access Journals (Sweden)

    Wernhuar Tarng

    2014-02-01

    Full Text Available As the advance of technology, the manufacturing process of materials has moved forward from the scale of micrometer to sub-micrometer and nanometer. Combining nanotechnology and traditional magnetic materials, nanoscale magnetic materials can be created for applications in biomedical examination and therapy as well as data recording to increase the storage space of a computer. The topic of using the magnetic force microscope (MFM to exam a material’s magnetic field distribution can often be found in nanotechnology courses. Due to the cost of equipment and difficulty of its operation, the teacher can only teach students with an instructional video most of the time instead of using a real MFM to conduct experiments. As a result, students may not fully understand its principle and operating procedure. In this study, a virtual MFM laboratory was designed as an app for execution on tablet computers to increase students’ learning interest and motivation. Without using expensive equipment, they can understand the magnetic field distribution of materials by using the virtual MFM to examine different samples provided in the virtual laboratory. A teaching experiment was also conducted to compare the learning effectiveness of using an instructional video and the virtual MFM laboratory. The experimental results showed that using the virtual MFM laboratory was more effective than using the instructional video; the questionnaire results also revealed that most students had positive attitudes toward the virtual MFM laboratory and they thought it could enhance their learning interest and motivation.

  13. Single step synthesis, characterization and applications of curcumin functionalized iron oxide magnetic nanoparticles.

    Science.gov (United States)

    Bhandari, Rohit; Gupta, Prachi; Dziubla, Thomas; Hilt, J Zach

    2016-10-01

    Magnetic iron oxide nanoparticles have been well known for their applications in magnetic resonance imaging (MRI), hyperthermia, targeted drug delivery, etc. The surface modification of these magnetic nanoparticles has been explored extensively to achieve functionalized materials with potential application in biomedical, environmental and catalysis field. Herein, we report a novel and versatile single step methodology for developing curcumin functionalized magnetic Fe3O4 nanoparticles without any additional linkers, using a simple coprecipitation technique. The magnetic nanoparticles (MNPs) were characterized using transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric analysis. The developed MNPs were employed in a cellular application for protection against an inflammatory agent, a polychlorinated biphenyl (PCB) molecule. PMID:27287099

  14. Magnetic susceptibility and magnetic resonance measurements of the moisture content and hydration condition of a magnetic mixture material

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, K., E-mail: tsukada@cc.okayama-u.ac.jp; Kusaka, T.; Saari, M. M.; Takagi, R.; Sakai, K.; Kiwa, T. [The Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-Naka, Okayama 700-8530 (Japan); Bito, Y. [Central Research Lab., Hitachi. Ltd., 1-280 Higashi-Koigakubo, Kokubunji, Tokyo 185-8601 (Japan)

    2014-05-07

    We developed a magnetic measurement method to measure the moisture content and hydration condition of mortar as a magnetic mixture material. Mortar is a mixture of Portland cement, sand, and water, and these materials exhibit different magnetic properties. The magnetization–magnetic field curves of these components and of mortars with different moisture contents were measured, using a specially developed high-temperature-superconductor superconducting quantum interference device. Using the differences in magnetic characteristics, the moisture content of mortar was measured at the ferromagnetic saturation region over 250 mT. A correlation between magnetic susceptibility and moisture content was successfully established. After Portland cement and water are mixed, hydration begins. At the early stage of the hydration/gel, magnetization strength increased over time. To investigate the magnetization change, we measured the distribution between bound and free water in the mortar in the early stage by magnetic resonance imaging (MRI). The MRI results suggest that the amount of free water in mortar correlates with the change in magnetic susceptibility.

  15. Development of Power Electronics Based Test Platform for Characterization and Testing of Magnetocaloric Materials

    Directory of Open Access Journals (Sweden)

    Deepak Elamalayil Soman

    2015-01-01

    Full Text Available Magnetocaloric effects of various materials are getting more and more interesting for the future, as they can significantly contribute towards improving the efficiency of many energy intensive applications such as refrigeration, heating, and air conditioning. Accurate characterization of magnetocaloric effects, exhibited by various materials, is an important process for further studies and development of the suitable magnetocaloric heating and cooling solutions. The conventional test facilities have plenty of limitations, as they focus only on the thermodynamic side and use magnetic machines with moving bed of magnetocaloric material or magnet. In this work an entirely new approach for characterization of the magnetocaloric materials is presented, with the main focus on a flexible and efficient power electronic based excitation and a completely static test platform. It can generate a periodically varying magnetic field using superposition of an ac and a dc magnetic field. The scale down prototype uses a customized single phase H-bridge inverter with essential protections and an electromagnet load as actuator. The preliminary simulation and experimental results show good agreement and support the usage of the power electronic test platform for characterizing magnetocaloric materials.

  16. Magnetic characterization of superparamagnetic nanoparticles pulled through model membranes

    OpenAIRE

    Barnes, Allison L; Wassel, Ronald A; Mondalek, Fadee; Chen, Kejian; Dormer, Kenneth J; Richard D. Kopke

    2007-01-01

    Background To quantitatively compare in-vitro and in vivo membrane transport studies of targeted delivery, one needs characterization of the magnetically-induced mobility of superparamagnetic iron oxide nanoparticles (SPION). Flux densities, gradients, and nanoparticle properties were measured in order to quantify the magnetic force on the SPION in both an artificial cochlear round window membrane (RWM) model and the guinea pig RWM. Methods Three-dimensional maps were created for flux density...

  17. Growth of novel-diluted magnetic semiconducting material Ge 1-xMn x and X-ray characterization by the maximum entropy method (MEM) and pair distribution function (PDF)

    Science.gov (United States)

    Syed Ali, K. S.; Saravanan, R.; Israel, S.

    2009-02-01

    The growth and electronic structural studies of diluted magnetic semiconducting (DMS) materials Ge 0.93Mn 0.07 and Ge 0.97Mn 0.03 have been carried out. The melt growth technique has been used for growing these samples. Electronic structure has been studied using the maximum entropy method (MEM) using X-ray powder data sets. The covalent nature of bonding and the interaction between the atoms are clearly revealed by these studies. One-dimensional electron density profile along bonding and non-bonding directions have been plotted to understand the details of bonding very clearly. The mid-bond electron density between the atoms is 0.377 e/Å 3 for Ge 0.93Mn 0.07 and 0.455 e/Å 3 for Ge 0.97Mn 0.03. The local structure of these materials has been determined using the pair distribution function (PDF) analysis and the changes in the nearest neighbor distances are quantified and analyzed.

  18. Hard magnetic composite materials with polymer matrix reinforced Nd-Fe-B hard magnetic particles

    International Nuclear Information System (INIS)

    Investigation results of the polymer matrix hard magnetic composite materials with particles of the powered rapid quenched Nd-Fe-B strip quenched Nd-Fe-B strip are presented at this paper. The Nd-Fe-B powder was doped (10 wt.%) with powder of iron, aluminium, CuSn10 casting copper alloy with tin, high alloy steel X2CrNiNo17-12-2 and aluminium oxide. Epoxy resin has been used as a matrix (2.5 wt.%). The pressure of 800-900 MPa and cured afterwards for 2 hours at 180 oC. The influence of dopes' materials kind on magnetic and mechanical composites were unilaterally and uniaxially pressed at room temperature under properties of composite materials was estimated. Metallographic examination of the composite materials' structure and XRD analysis has been made. Investigations of magnetic properties of composite materials show the influence of the addition material. It was estimated that dopes of soft magnetic material decrease coercive force HcB and slightly reduce remanence Br of composite. The addition of non-magnetic material decreases coercive force HcB and reduces remanence Br. Metallographic examination of the structure shows uniform distribution of Nd-Fe-B powder in the polymer matrix, grains are irregular elongated in the direction. Dopes distribution in a polymer matrix is irregular, agglomerations of powders of aluminium, iron and copper casting alloy with tin have noticed. Ultimate compressive strength of composite materials is improved for all the addition material, except powder of aluminium oxide. XRD analysis has identified the hard magnetic phase Nd2Fe14B. (author)

  19. Synthesis and Characterization of Polyaniline in Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    MA Li; ZHENG Xing; GAN Mengyu; DU Xinsheng; FENG Lijun

    2008-01-01

    Polyaniline was obtained by chemical oxidation in the microemulsion system consisting of aniline, emulsifier, assistant emulsifier and water in magnetic field (0 T, 0.2 T, 0.4 T, 0.6 T). The effect of magnetic field on the polymerization rate and the inherent viscosity of polyaniline were studied. The molecular structure of polyaniline was characterized by IR spectra and the thermal degradation behavior was assessed using TG techniques. The results show that the polymerization rate, molecular weight, thermal stability and conductivity of the synthesized polyaniline enhanced and no effect on the basic structural units of polyaniline was observed in magnetic field. Within the range of the intensity of magnetic field studied, the magnetic field of 0.4 T exerts the largest influence on polymerization of aniline.

  20. Hydrogenated arsenenes as planar magnet and Dirac material

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shengli; Cai, Bo; Zeng, Haibo, E-mail: Huziyu@csrc.ac.cn, E-mail: zeng.haibo@njust.edu.cn [Institute of Optoelectronics and Nanomaterials, Herbert Gleiter Institute of Nanoscience, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Hu, Yonghong [Institute of Optoelectronics and Nanomaterials, Herbert Gleiter Institute of Nanoscience, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); School of Nuclear Technology and Chemistry and Biology, Hubei University of Science and Technology, Xianning 437100 (China); Hu, Ziyu, E-mail: Huziyu@csrc.ac.cn, E-mail: zeng.haibo@njust.edu.cn [Beijing Computational Science Research Center, Beijing 100084 (China)

    2015-07-13

    Arsenene and antimonene are predicted to have 2.49 and 2.28 eV band gaps, which have aroused intense interest in the two-dimensional (2D) semiconductors for nanoelectronic and optoelectronic devices. Here, the hydrogenated arsenenes are reported to be planar magnet and 2D Dirac materials based on comprehensive first-principles calculations. The semi-hydrogenated (SH) arsenene is found to be a quasi-planar magnet, while the fully hydrogenated (FH) arsenene is a planar Dirac material. The buckling height of pristine arsenene is greatly decreased by the hydrogenation, resulting in a planar and relatively low-mass-density sheet. The electronic structures of arsenene are also evidently altered after hydrogenating from wide-band-gap semiconductor to metallic material for SH arsenene, and then to Dirac material for FH arsenene. The SH arsenene has an obvious magnetism, mainly contributed by the p orbital of the unsaturated As atom. Such magnetic and Dirac materials modified by hydrogenation of arsenene may have potential applications in future optoelectronic and spintronic devices.

  1. Synthesis and characterization of nanoscale magnetic drug-inorganic composites

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; ZHANG Hui; David G. Evans; DUAN Xue

    2005-01-01

    The synthesis by direct coprecipitation and characterization of captopril (Cpl) and 5-aminosalicylic acid (5-ASA) intercalated ZnAl layered double hydroxides coated on MgFe2O4 magnetic core particles are reported. Powder XRD analysis shows the well-defined crystallite structure of the composites. TEM and XPS results reveal that a core-shell structure involving a drug-LDHs layer coated on MgFe2O4 particles is formed through Zn-O-Mg and/or Al-O-Mg linkages. VSM measurements demonstrate that the novel magnetic drug-inorganic composites possess considerable magnetization.

  2. Low dimensional magnetism and nanograined materials - magnetometry, magnetooptics and laser-ultrasound

    International Nuclear Information System (INIS)

    the magnetism of porous FePd and FePt is investigated in collaboration with the TU Graz (Institute of Materials' Science). The electric charging of the compacted powder is performed by loading with an electrolyte and measuring the magnetic response by SQUID-magnetometry. Simulations of magneto-optic Kerr spectra are performed by M. Hofmayer (PhD) for InMnAs-, InMnSb- ferromagnetic semiconductors in quantizing magnetic fields in close cooperation with Univ. Bayreuth (H. Pascher) and Univ. of Notre Dame, USA (J. Furdyna). This modelling project is supported by the NAWI Graz cooperation with TU Graz. The available equipment at the location of the group consists of cryogenic facilities (cryostats, temperature controller), fiber optic sample holder, Nd:Yag solid state laser, time-resolving ultrasound prober, electrochemical cells for deposition using pulsed charging, potentiostat, SQUID-magnetometry, FTIR-spectrometry, time-resolved luminescence in VIS, MOKE-, Faraday-rotation, ESR-spectroscopy, detection and analysis of Barkhausen noise, versatile semiconductor probing device for magnetoresistance and Hall-effect, and Rapid Thermal Annealing (RTA) facility for 6'' silicon wafers. Furthermore structural characterizations are carried out in close collaboration with the TUG (Institute for Electron Microscopy, FELMI). The personnel consists of 2 permanent staff members (incl. the head), 3 Postdocs, 7 PhD's and 1 diploma student. Current projects are: FWF P18593: Ir/Regular magnetic nanowires in porous silicon; NFN-network S10407-N16: bulk-nanostructured materials: nondestructuve testing of nancrystalline materials by Barkhausen noise, ultrasound and magneto-optic Kerr effect; NAWI Graz cooperation project: magnetic and optic properties of nanocrystalline materials applied projects: Doktorats-Kolleg C53 nanostructured systems: self-assembly, hierarchical ordering and materials foundations, Sub-Projekt: C53.3 (H. Krenn): fabrication of self assembled ferromagnet

  3. Hybrid magnetic/semiconductor spintronic materials and devices

    International Nuclear Information System (INIS)

    We report our experimental studies of different kinds of magnetic/semiconductor hybrid materials and devices highly promising for the next generation spintronics. The epitaxial Fe films on three III-V Semiconductor surfaces, InxGa1-xAs(100), x=0, 1, 0.2, show a uniaxial magnetic anisotropy in the ultrathin region. This suggests that both interface bonding and the magnetoelastic effect control magnetic anisotropy. We demonstrate the epitaxial growth of new hybrid spintronic structures, namely, Fe3O4/GaAs and Fe3O4/MgO/GaAs, where the magnetic oxide has both high Curie temperature and high spin polarisation. Both the magnetisation loops and magneto-resistance curves of Fe3O4/GaAs were found to be dominated by a strong uniaxial magnetic anisotropy. We have also fabricated a novel vertical hybrid spin device, i.e. Co(15ML)/GaAs(50nm, n-type)/Al0.3Ga0.7As(200nm, n-type)/FeNi(30nm) and observed for the first time a change of the magneto-resistance up to 12% by direct transport measurements, which demonstrated large spin injection and the feasibility to fabricate the spin-transistors capable of operating at room temperatures by using magnetic/semiconductor hybrid materials

  4. Synthesis and characterization of robust magnetic carriers for bioprocess applications

    International Nuclear Information System (INIS)

    Highlights: • Silica magnetic microparticles were synthesized for applications in bioprocesses. • The process to produce magnetic microparticles is inexpensive and easily scalable. • Microparticles with very high saturation magnetization were obtained. • The structure of the silica magnetic microparticles could be controlled. - Abstract: Magnetic carriers are an effective option to withdraw selected target molecules from complex mixtures or to immobilize enzymes. This paper describes the synthesis of robust silica magnetic microparticles (SMMps), particularly designed for applications in bioprocesses. SMMps were synthesized in a micro-emulsion, using sodium silicate as the silica source and superparamagnetic iron oxide nanoparticles as the magnetic core. Thermally resistant particles, with high and accessible surface area, narrow particle size distribution, high saturation magnetization, and with superparamagnetic properties were obtained. Several reaction conditions were tested, yielding materials with saturation magnetization between 45 and 63 emu g−1, particle size between 2 and 200 μm and average diameter between 11.2 and 15.9 μm, surface area between 49 and 103 m2 g−1 and pore diameter between 2 and 60 nm. The performance of SMMps in a bioprocess was evaluated by the immobilization of Pseudomonas fluorescens lipase on to octyl modified SMMp, the biocatalyst obtained was used in the production of butyl butyrate with good results

  5. Synthesis and characterization of robust magnetic carriers for bioprocess applications

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Willian, E-mail: willkopp@gmail.com [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Silva, Felipe A., E-mail: eq.felipe.silva@gmail.com [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Lima, Lionete N., E-mail: lionetenunes@yahoo.com.br [Federal University of São Carlos-UFSCar, Graduate Program in Chemical Engineering, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Masunaga, Sueli H., E-mail: sueli.masunaga@gmail.com [Department of Physics, Montana State University-MSU, 173840, Bozeman, MT 59717-3840 (United States); Tardioli, Paulo W., E-mail: pwtardioli@ufscar.br [Department of Chemical Engineering, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Giordano, Roberto C., E-mail: roberto@ufscar.br [Department of Chemical Engineering, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); Araújo-Moreira, Fernando M., E-mail: faraujo@df.ufscar.br [Department of Physics, Federal University of São Carlos-UFSCar, Rodovia Washington Luiz, km 235, São Carlos, São Paulo 13565-905 (Brazil); and others

    2015-03-15

    Highlights: • Silica magnetic microparticles were synthesized for applications in bioprocesses. • The process to produce magnetic microparticles is inexpensive and easily scalable. • Microparticles with very high saturation magnetization were obtained. • The structure of the silica magnetic microparticles could be controlled. - Abstract: Magnetic carriers are an effective option to withdraw selected target molecules from complex mixtures or to immobilize enzymes. This paper describes the synthesis of robust silica magnetic microparticles (SMMps), particularly designed for applications in bioprocesses. SMMps were synthesized in a micro-emulsion, using sodium silicate as the silica source and superparamagnetic iron oxide nanoparticles as the magnetic core. Thermally resistant particles, with high and accessible surface area, narrow particle size distribution, high saturation magnetization, and with superparamagnetic properties were obtained. Several reaction conditions were tested, yielding materials with saturation magnetization between 45 and 63 emu g{sup −1}, particle size between 2 and 200 μm and average diameter between 11.2 and 15.9 μm, surface area between 49 and 103 m{sup 2} g{sup −1} and pore diameter between 2 and 60 nm. The performance of SMMps in a bioprocess was evaluated by the immobilization of Pseudomonas fluorescens lipase on to octyl modified SMMp, the biocatalyst obtained was used in the production of butyl butyrate with good results.

  6. Applications of the Raman spectroscopy in the materials characterization

    International Nuclear Information System (INIS)

    The study field of the science and technology of surfaces and materials have been of primordial importance in the last years due to the impact that they have the knowledge that it generates in diverse areas. For this reason, the Mexican Society of Science and Technology of Surfaces and Materials has focused a good part of their investigation activities toward the materials science and technology development. Inside the investigation fields carried out by members of this Society, are the following: semiconductors, thin films, hard coatings, deposit techniques, plasmas, biomaterials, Ab-initio calculations, characterization techniques, photo-thermal properties, solar cells, nano science, magnetism, superconductivity and related topics. Among the techniques used for this purpose is the Raman Spectroscopy (Rs), which has demonstrated to be a powerful and versatile tool in the materials study. In the last three congresses that the Society has organized, an average of 42 works related with this topic have been presented, what gave the rule to prepare this book whose objective is on one hand diffusing part of the works that carry out different groups integrated with members of the Society that use the Rs like an important tool in its investigation work. A second objective is that it can serve like support to the students that begin to be involved, or that they are already involved, in topics where the Rs can have a decisive paper in the development of its projects. It is also expected that some of the topics included in the book are of utility for professors and researches that already uses the Rs, or that it can be of help for those who are beginning in this technique as alternative or like complementary analysis tool. (Author)

  7. Effects of the magnetic field on the structure of materials

    International Nuclear Information System (INIS)

    This is a report of the ''Meeting on the effects of a magnetic field on the structure of materials'' held at KEK, Japan. The purpose of the Meeting was to study the diffraction of SR X-ray in a magnetic field. It was found that the effects of a magnetic field have been seen in various substnaces. The effects are due to the Zeeman effect, the Lamor diamagnetism, the Landau diamagnetism, the Meissner effect and the polarization effect. The topics discussed at the Meeting were the structure study of biological specimens by field orientation, the study of cell structure by field orientation, the phase transition under a strong pulse field, the behavior of high molecular liquid crystal in a magnetic field, the change of the f-electron density of the Tb3+ ions in Tb IG in a magnetic field at low temperature, an electromagnet loaded on a goniometer and an in-situ observation system for the structure of magnetic domain, the control of structural phase transition by a magnetic field, the use of synchrotron orbit radiation for the structural analysis of random systems, and the field effect on chemical reactions. (Kato, T.)

  8. 2nd Latin American Workshop on Magnetism, Magnetic Materials, and Their Applications

    CERN Document Server

    Sanchez, J

    1994-01-01

    During August 24-27, 1993, approximately 60 scientists from the Americas, Europe and Japan, gathered in the city of Guanajuato, in the state of Guanajuato, Mexico, at the II Latin American Workshop on Magnetism, Magnetic Materials and their Applications. The group of scientists converging into the beautiful city of Guanajuato had come from Argentina, Chile, Brazil, Venezuela, Cuba, several places in Mexico, U. S. A. , Japan, Spain, France, Italy, Germany, Austria, Switzerland, and Denmark. The event attested to the success of the previous Workshop on Magnetism, Magnetic Materials and their Applications, held in Havana, Cuba, in 1991, as well as to the interest, level of activity and quality of the work being carried out in Latin America in the area of magnetism and magnetic materials. Equally important to everyone present was the fact that we had come to honor a friend, Professor L. M. Falicov, on his sixtieth birthday. The choice of a Latin American Workshop on magnetism as a Festschrift for Leo Falicov was,...

  9. Synthesis and characterization of magnetic palygorskite nanoparticles and their application on methylene blue remotion from water

    Science.gov (United States)

    Middea, Antonieta; Spinelli, Luciana S.; Souza, Fernando G.; Neumann, Reiner; Gomes, Otavio da F. M.; Fernandes, Thais L. A. P.; de Lima, Luiz C.; Barthem, Vitoria M. T. S.; de Carvalho, Fernanda V.

    2015-08-01

    Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10-4 Am2/kg to about 20 Am2/kg. A weight loss was also observed around 277 °C-339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite.

  10. Magnetic mesoporous materials for removal of environmental wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byoung Chan; Lee, Jinwoo; Um, Wooyong; Kim, Jaeyun; Joo, Jin; Lee, Jin Hyung; Kwak, Ja Hun; Kim, Jae Hyun; Lee, Changha; Lee, Hongshin; Addleman, Raymond S.; Hyeon, Taeghwan; Gu, Man Bock; Kim, Jungbae

    2011-09-15

    We have synthesized two different magnetic mesoporous materials that can be easily separated from aqueous solutions by applying a magnetic field. Synthesized magnetic mesoporous materials, Mag-SBA-15 (magnetic ordered mesoporous silica) and Mag-OMC (magnetic ordered mesoporous carbon), have a high loading capacity of contaminants due to high surface area of the supports and high magnetic activity due to the embedded iron oxide particles. Application of surface-modified Mag-SBA-15 was investigated for the collection of mercury from water. The mercury adsorption using Mag-SBA-15 was rapid during the initial contact time and reached a steady-state condition, with an uptake of approximately 97% after 7 hours. Application of Mag-OMC for collection of organics from water, using fluorescein as an easily trackable model analyte, was explored. The fluorescein was absorbed into Mag-OMC within minutes and the fluorescent intensity of solution was completely disappeared after an hour. In another application, Mag-SBA-15 was used as a host of tyrosinase, and employed as recyclable catalytic scaffolds for tyrosinase-catalyzed biodegradation of catechol. Tyrosinase aggregates in Mag-SBA-15, prepared in a two step process of tyrosinase adsorption and crosslinking, could be used repeatedly for catechol degradation with no serious loss of enzyme activity. Considering these results of cleaning up water from toxic inorganic, organic and biochemical contaminants, magnetic mesoporous materials have a great potential to be employed for the removal of environmental contaminants and potentially for the application in large-scale wastewater treatment plants.

  11. Synthesis and characterization of magnetic nanoparticles embedded in polyacrylonitrile nanofibers

    Science.gov (United States)

    Munteanu, Daniel; Ion, Rodica-Mariana; Cocina, George-Costel

    2010-11-01

    Nanomedicine is defined as the monitoring, repair, construction, and control of human biological systems at the molecular level using engineered nanodevices and nanostructures. Polyacrylonitrile (PAN) solution containing the iron oxide precursor iron (III) was electrospun and thermally treated to produce electrically conducting, magnetic carbon nanofiber mats with hierarchical pore structures. This paper discusses the synthesis of magnetite (Fe3O4) nanoparticles with mean crystallite size of 10 nm with polyacrylonitrile (PAN) as the protecting agent, creating nanofiber. The morphology and material properties of the resulting multifunctional nanofiber including the surface area were examined using various characterization techniques. Optical microscopy images show that uniform fibers were produced with a fiber diameter of ~600 nm, and this uniform fiber morphology is maintained after graphitization with a fiber diameter of ~330 nm. X-ray diffraction (XRD) studies reveal the size of Fe3O4 crystals. A combination of XRD and electron microscopy experiments reveals the formation of pores with graphitic nanoparticles in the walls as well as the formation of magnetite nanoparticles distributed throughout the fibers.

  12. Magnetic characterisation of recording materials: design, instrumentation and experimental methods

    NARCIS (Netherlands)

    Samwel, E.O.

    1995-01-01

    The progress being made in the field of magnetic recording is extremely fast. The need to keep this progress going, leads to new types of recording materials which require advanced measurement systems and measurement procedures. Furthermore, the existing measurement methods need to be reviewed as du

  13. Material properties and modeling characteristics for MnFeP1-xAsx materials for application in magnetic refrigeration

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Bahl, Christian R.H.; Carroll, C. P.; van Asten, D.

    2013-01-01

    Compounds of MnFeP1-xAsx have received attention recently for their use in active magnetic regenerators (AMR) because of their relatively high isothermal entropy change and adiabatic temperature change with magnetization. However, the materials also generally exhibit a significant magnetic and...... impact of hysteresis is a key element to guide successful material development and synthesis. The properties of a magnetocaloric MnFeP1-xAsx compound are characterized as a function of temperature and applied magnetic field, and the results are used to assess the effects of hysteresis on magnetocaloric...... thermal hysteresis, and it is not well understood how the hysteresis will affect performance in a practical AMR device. The amount of hysteresis shown by a material can be controlled to an extent by tuning the processing conditions used during material synthesis; therefore, knowledge of the practical...

  14. Preparation and characterization of porous magnesium materials

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-qin; LIU Zi-li; ZHANG Xiao-hong; FENG Jun-dong; YU Ta-xi

    2006-01-01

    The proper spacer material and the preparation technology for biological compatible porous magnesium materials were explored by the powder metallurgy method, and microstructures, porosity and mechanical properties of sintered porous magnesium were investigated. The results show that compared with spacer materials of NH4CO3, NH3Cl and carbamide, NH4CO3 is the best one for preparation of sintered porous magnesium, and the worst one is NH3Cl. The isolated blind pores are formed mainly by the particle interval of the magnesium powders. Adding spacer material favors the formation of open pores, while has little contribution to the formation of blind pores. The overall porosity and porosity of open pore of the sintered porous magnesium increase with the increase of added spacer material, while decrease with the increase of the molding stress. The mechanical properties of sintered porous magnesium increase with decreasing addition of spacer material and increasing molding stress.

  15. Characterization of Materials by Vibration Technique

    OpenAIRE

    2011-01-01

    This paper presents an experimental investigation of two different kinds of plates of materials namely glass and stainless steel by experimental modal analysis. The materials are excited by an impact hammer to perform resonant vibration where the characteristics of the resonance are acquired. One most important characteristic is the natural frequency where it is known that different material having undergone resonant vibration exhibit different specific natural frequencies to it. The natural ...

  16. Materials, preparation, and characterization in thermoelectrics

    CERN Document Server

    Rowe, David Michael

    2012-01-01

    This book includes updated theoretical considerations which provide an insight into avenues of research most likely to result in further improvements in material performance. It details the latest techniques for the preparation of thermoelectric materials employed in energy harvesting, together with advances in the thermoelectric characterisation of nanoscale material. The book reviews the use of neutron beams to investigate phonons, whose behaviour govern the lattice thermal conductivity and includes a chapter on patents.

  17. A Comparative Study: Dynamic and Thermal Behavior of Nanocrystalline and Powder Magnetic Materials in a Power Converter Application

    Science.gov (United States)

    Hilal, A.; Raulet, M. A.; Martin, C.; Sixdenier, F.

    2015-10-01

    In the design of such power electronics applications as power converters, lack of precise characterization and diagnosis of losses from components has unacceptable effects on efficiency, reliability, and power consumption. Because passive components, especially magnetic components, are crucially important in power converters, accurate characterization and modeling of magnetic materials is mandatory, to enable realistic prediction of their behavior under variable operating conditions. Temperature is one such condition that induces major changes in a component's behavior by modifying the material's magnetic properties. In the work discussed in this paper we investigated the magnetic and thermal behavior of nanocrystalline and powder materials in a DC-DC converter application. Core loss measurements under variable conditions were performed on toroid-shaped samples. Measured results were analyzed for different frequencies, flux densities, and temperatures.

  18. Application of magnetic nanoparticles and reactive filter materials for wastewater treatment

    OpenAIRE

    Lakshmanan, Ramnath

    2013-01-01

    Lately sewage wastewater treatment processes (WWTP) are facing challenges due to strict regulations in quality of effluent standards and waste production. The reuse of wastewater treatment effluents is rapidly gaining attention as a means of achieving sustainable water supply. Therefore, new methods are required to achieve an efficient WWTP. The foremost emphasis of the present study is to investigate filter materials, synthesis, characterization, and application of magnetic nanoparticles (NP...

  19. Solid state nuclear magnetic resonance investigations of advanced energy materials

    Science.gov (United States)

    Bennett, George D.

    In order to better understand the physical electrochemical changes that take place in lithium ion batteries and asymmetric hybrid supercapacitors solid state nuclear magnetic resonance (NMR) spectroscopy has been useful to probe and identify changes on the atomic and molecular level. NMR is used to characterize the local environment and investigate the dynamical properties of materials used in electrochemical storage devices (ESD). NMR investigations was used to better understand the chemical composition of the solid electrolyte interphase which form on the negative and positive electrodes of lithium batteries as well as identify the breakdown products that occur in the operation of the asymmetric hybrid supercapacitors. The use of nano-structured particles in the development of new materials causes changes in the electrical, structural and other material properties. NMR was used to investigate the affects of fluorinated and non fluorinated single wall nanotubes (SWNT). In this thesis three experiments were performed using solid state NMR samples to better characterize them. The electrochemical reactions of a lithium ion battery determine its operational profile. Numerous means have been employed to enhance battery cycle life and operating temperature range. One primary means is the choice and makeup of the electrolyte. This study focuses on the characteristics of the solid electrolyte interphase (SEI) that is formed on the electrodes surface during the charge discharge cycle. The electrolyte in this study was altered with several additives in order to determine the influence of the additives on SEI formation as well as the intercalation and de-intercalation of lithium ions in the electrodes. 7Li NMR studies where used to characterize the SEI and its composition. Solid state NMR studies of the carbon enriched acetonitrile electrolyte in a nonaqueous asymmetric hybrid supercapacitor were performed. Magic angle spinning (MAS) coupled with cross polarization NMR

  20. Magnetic Separation for Nuclear Material Detection and Surveillance

    International Nuclear Information System (INIS)

    A high performance superconducting magnet is being developed for particle retrieval from field collected samples. Results show that maximum separation effectiveness is obtained when the matrix fiber diameter approaches the diameter of the particles to be captured. Experimentally, the authors obtained a single particle capture limit with 0.8microm PuO2 particles with dodecane as a carrier fluid. The development of new matrix materials is being pursued through the controlled corrosion of stainless steel wool, or the deposition of nickel dendrites on the existing stainless steel matrix material. They have also derived a model from a continuity equation that uses empirically determined capture cross section values. This enables the prediction of high gradient magnetic separator performance for a variety of materials and applications. The model can be used to optimize the capture cross section and thus increase the capture efficiency

  1. Production and characterization of magnetic nanoparticles prepared by sol-gel processing

    International Nuclear Information System (INIS)

    Full text: There is a great technological interest in the synthesis of iron oxide nanocomposites due to their magnetic and catalytic properties. Magnetic nanocomposites have gained acceptance in several fields of application of nanomaterials, like in magnetic recording systems, magnetic refrigeration, magneto-optical solid devices, magnetic resonance imaging, bioprocessing and in flow systems. The preparation of pure nano phase iron oxide nanocomposite material has, presently, some difficulties arising from different oxidation states of iron which can lead to the presence of various oxides. The stabilization of iron oxide nanoparticles is usually achieved by dispersing them in a polymeric, glassy or ceramic matrix. Matrix support, which in principle, modifies the properties of nanomaterials, thus opening new possibilities to the control of their performance. In this study, we report the preparation of an Fe2O3-SiO2 nanocomposite and Fe3O4 nanoparticles through a sol-gel method. A multitechnique approach, by XRD, SEM/EDS and VSM (Vibrating Sample Magnetometer), was used to characterize the structure and the magnetic properties of the nanoparticles. VSM measurements were conducted at different temperatures. XRD spectra showed that the Surface Area/Volume ratio adopted in the process of gelation influences the characteristics of the material obtained. For magnetite, the typical size of resulting Fe3O4 magnetic nanoparticles was approximately 14 nm

  2. Superconductor Requirements and Characterization for High Field Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Barzi, E.; Zlobin, A. V.

    2015-05-01

    The 2014 Particle Physics Project Prioritization Panel (P5) strategic plan for U.S. High Energy Physics (HEP) endorses a continued world leadership role in superconducting magnet technology for future Energy Frontier Programs. This includes 10 to 15 T Nb3Sn accelerator magnets for LHC upgrades and a future 100 TeV scale pp collider, and as ultimate goal that of developing magnet technologies above 20 T based on both High Temperature Superconductors (HTS) and Low Temperature Superconductors (LTS) for accelerator magnets. To achieve these objectives, a sound conductor development and characterization program is needed and is herein described. This program is intended to be conducted in close collaboration with U.S. and International labs, Universities and Industry.

  3. Advanced Metrology for Characterization of Magnetic Tunnel Junctions

    DEFF Research Database (Denmark)

    Kjær, Daniel

    -plane tunneling (CIPT) for characterization of magnetic tunnel junctions (MTJs), which constitutes the key component not only in MRAM but also the read-heads of modern hard disk drives. MTJs are described by their tunnel magnetoresistance (TMR), which is the relative difference of the resistance area products (RA...... may effectively increases the dynamic range of any given micro 12-point probe (M12PP). Without the requirement for switching magnetic fields during measurements the static field CIPT method has inspired the concept of detached magnet setups for future CIPTech tools. While lowering the complexity of......) at two characteristic resistance levels (high and low) of the MTJ device. In the final memory application these resistance states correspond to a digital “1” or “0” stored. During CIPT measurements the tool will alter the state of the MTJ by application of an external magnetic field. With the CIPTech...

  4. Magnon-phonon interconversion in a dynamically reconfigurable magnetic material

    Science.gov (United States)

    Guerreiro, Sergio C.; Rezende, Sergio M.

    2015-12-01

    The ferrimagnetic insulator yttrium iron garnet (YIG) is an important material in the field of magnon spintronics, mainly because of its low magnetic losses. YIG also has very low acoustic losses, and for this reason the conversion of a state of magnetic excitation (magnons) into a state of lattice vibration (phonons), or vice versa, broadens its possible applications in spintronics. Since the magnetic parameters can be varied by some external action, the magnon-phonon interconversion can be tuned to perform a desired function. We present a quantum theory of the interaction between magnons and phonons in a ferromagnetic material subject to a dynamic variation of the applied magnetic field. It is shown that when the field gradient at the magnetoelastic crossover region is much smaller than a critical value, an initial elastic excitation can be completely converted into a magnetic excitation, or vice versa. This occurs with conservation of linear momentum and spin angular momentum, implying that phonons created by the conversion of magnons have spin angular momentum and carry spin current. It is shown further that if the system is initially in a quantum coherent state, its coherence properties are maintained regardless of the time dependence of the field.

  5. An overstoichiometric Nd–Fe–B hard magnetic material

    Directory of Open Access Journals (Sweden)

    TOMÁŠ ŽÁK

    2010-09-01

    Full Text Available A commercial Nd-rich Nd–Fe–B-based hard magnetic material was studied. The obtained results were compared before and after recording of the thermomagnetic curve up to 800 °C. The curve itself showed clearly besides Curie points of the Nd2Fe14B phase and α-Fe also another critical temperature. Mössbauer spectroscopic (MS phase analysis and X-ray diffraction analysis (XRD showed in addition to the commonly known phases Nd2Fe14B and NdFe4B4 also some paramagnetic and ferromagnetic iron atoms (MS and Fe17Nd2 intermetallics (XRD. During the exerted thermal treatment, the content of the Nd2Fe14B and NdFe4B4 phases remained almost unchanged, while iron atoms from remnant minor phases built a separate α-Fe phase. The XRD pattern also showed the presence of some minor Nd phase. The results of Squid magnetic measurements suggest a nanocrystalline decoupled structure of the Nd-rich alloy in the optimized magnetic state. Measurement of the magnetization loop showed, in spite of small changes in the phase composition, that magnetic properties of the quality material deteriorated during the thermal treatment.

  6. Review of Magnetic Materials Along With a Study of the Magnetic Stability and Solidity of Y40

    OpenAIRE

    Karlsson, Joakim; Söderström, Ola

    2012-01-01

    Wave energy converters (WECs) are relatively new power sources under rapiddevelopment. WECs utilize permanent magnets to generate power and theperformance of these magnets have a great impact on the produced effects in theWECs. This paper is primarily constructed to investigate the magnetic and mechanicalproperties of a specific kind of permanent magnets, referred to as Y40. The paperalso gives a comprehensive review of magnetic materials in general, slightly focusingon magnetic stability. Li...

  7. [Application of magnetic materials in analysis on Chinese herb medicines].

    Science.gov (United States)

    Xu, Li-Wei; Wang, Jiu-Rong; Han, Xue-Feng

    2012-12-01

    China is the cradle of Chinese herb medicines,with rich plant resources. However, traditional processing methods have many disadvantages, such as high comsumption of organic solvent, long extraction time and high loss of effective constituents. For the purpose of rational use of Chinese herb medicines and accurate analysis on their constituents,the sample pre-treatment method with magnetic nanoparticles as the carrier brought new opportunities in recent years. after consulting literatures,the essay summarizes traditional extraction methods of Chinese herb medicines, characteristics of magnetic materials and their application in the analysis on Chinese herb medicines. PMID:23477130

  8. Incommensurate Magnetic Fluctuations in the Underdoped Copper Oxide Materials

    Institute of Scientific and Technical Information of China (English)

    YUAN Feng; FENG Shi-Ping; CHEN Wei-Yeu

    2001-01-01

    The doping dependence of magnetic fluctuations in the underdoped copper oxide materials are studied within the t-J model. It is shown that away from the half-filling, the magnetic Bragg peaks from the dynamical spin structure factor spectrum S(k, ω) are incommensurate with the lattice. Although the incommensurability δ(x) is almost energy-independent, the dynamical spin susceptibility x〃(k,ω) at the incommensurate wave vectors is changed dramatically with energies, which is consistent with the experiments.``

  9. Magnetic and material limiter discharges in Tokapole II

    International Nuclear Information System (INIS)

    Disruptive instabilities have been studied in Tokapole II, a small poloidal divertor tokamak, in magnetic and material limiter configurations. In the magnetic limiter configuration, the divertor separatrix defines the tokamak current channel boundary. Limiters or neutralizer plates are not used to remove plasma in the scrape-off region. The relatively hot, dense plasma in the scrape-off region carries 5--20% of the current. In the material limiter configuration, limiter plates are inserted to the separatrix to remove plasma and current in the scrape-off region. The plates vary the tokamak current channel boundary condition in a controlled manner, and provide a benchmark for comparison with other tokamaks. Internal and external disruptions have been studied, and several unique features in the magnetic limiter configuration have been identified. The magnitic limiter configuration enables routine passing of the stability barriers at q(a) = 2 and q(a) = 1, where q(a) is the the edge safety factor, without a close fitting wall, external windings, or detailed profile control techniques. Passing the q(a) = 1 barrier permits operation in the q < 1 regime where total reconnection of the sawtooth does not occur. Discharges with q < 1 are also obtained in the material limiter configuration, suggesting that partial reconnection is characteristic of the sawteeth, and not the magnetic limiter configuration. The magnetic limiter configuration suppresses current termination in a major disruption. Current termination occurs in material limiter discharges due to enhanced interaction with the inboard limiter following the post-disruptive shift in major radius

  10. Material Characterization using Digital Image Correlation

    Czech Academy of Sciences Publication Activity Database

    Jandejsek, Ivan; Vavřík, Daniel

    Ostrava: VŠB - Technical University of Ostrava, Faculty of Mechanical Engineering , Department of Mechanics of Materials, 2008 - (Fuxa, J.), s. 107-110 ISBN 978-80-248-1774-3. [Experimentální analýza napětí 2008. Horni Bečva (CZ), 02.06.2008-05.06.2008] Institutional research plan: CEZ:AV0Z20710524 Keywords : Digital Image Correlation * Optical measurement * Full-field measurement Subject RIV: JJ - Other Materials

  11. Materials characterization by resonant ultrasonic spectroscopy method

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Yong Moo; Jung, H.K.; Joo, Y.S.; Sim, C.M

    2001-01-01

    A high temperature resonant ultrasound spectroscopy(RUS) was developed. The dynamic elastic constant of RPV weld, which has various different microstructure was determined by RUS. It was confirmed the RUS method is very sensitive to the microstructures of the material. RUS can be used to monitor the degradation of nuclear materials including neutron irradiation embrittlement through the measurement of dynamic elastic constants, elastic anisotropy, high temperature elastic constant and Q-factor.

  12. Materials characterization by resonant ultrasonic spectroscopy method

    International Nuclear Information System (INIS)

    A high temperature resonant ultrasound spectroscopy(RUS) was developed. The dynamic elastic constant of RPV weld, which has various different microstructure was determined by RUS. It was confirmed the RUS method is very sensitive to the microstructures of the material. RUS can be used to monitor the degradation of nuclear materials including neutron irradiation embrittlement through the measurement of dynamic elastic constants, elastic anisotropy, high temperature elastic constant and Q-factor

  13. Effects of the magnetic field over the nanometric growth morphology on the material synthesis in a liquid spray thermal plasma reactor

    International Nuclear Information System (INIS)

    It is possible that the magnetic field affect the growth morphology of the materials at nanometric scale while there are synthesized. In this work is developed a thermal plasma reactor in fluidized bed assisted by magnetic mirror for material synthesis using a liquid spray. An aluminum solution is carrier in the plasma reactor with a without magnetic external magnetic field applied. We found from the characterization of material synthesized that: Aluminum nanowire and alumina nanofiber are generated when the external magnetic mirror is applied to the thermal plasma reactor.

  14. Vanadium oxide based materials: Synthesis, characterization and gas sensing properties

    Science.gov (United States)

    Ayesh, Samar I.

    In recent years, the demand for gas sensors based on safety and process control requirements has been expanding. The reason for such demand sterns from environmental and safety concerns since the toxic gases released from automobile exhausts and chemical plants can directly or indirectly pollute our environment and affect our health. Among the chemicals studied, nitrogen oxide (NOx) gases are among the most dangerous air pollutants. Transition metal oxide clusters (or polyoxometalates) provide an exciting opportunity for the design and synthesis of a new generation of materials for efficient NOx sensing. Polyoxometalates are an important and fast emerging class of compounds that exhibit many remarkable properties. Chapter 1 provides introduction and background of chemical sensors. It describes the need for gas sensors and the current status of research in the area of NOx gas sensors in particular. A description of polyoxmetalates and their relevance as potential novel gas sensor materials is also given. Chapter 2 describes the synthesis and characterization by FTIR spectroscopy, elemental analysis, thermogravimetric analysis, manganometric titration, bond valence sum calculation, temperature dependent magnetic properties studies, electron paramagnetic resonance, and complete single crystal X-ray diffraction analysis of newly prepared vanadium oxide based-systems that have been discovered during the course of this work. First, the system containing arrays of decavanadates networked by extensive hydrogen bonding with cyclic nitrogen bases are described. This is followed by the mixed-valence vanadium oxide cluster, [VV 13VIV3O42(Cl)]-7, containing a hitherto unknown vanadium oxide framework structure. Finally the synthesis of 3D-framework materials is described. These compounds have highly symmetrical closely related three-dimensional framework structures consisting vanadium oxide shells {V18O42(XO4)} linked via heterometallic atoms {M' = Cd, Zn} into three

  15. Structure and magnetic properties of powder HITPERM material

    Directory of Open Access Journals (Sweden)

    J.E. Frąckowiak

    2007-03-01

    Full Text Available Purpose: The aim of the work is to investigate the structure and magnetic properties of the cobalt based HITPERM amorphous alloy Co68Fe4Mo1Si13.5B13.5 subjected high-energy ball milling and to the isothermal annealing to a combination of these two technologies.Design/methodology/approach: The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling of metallic glasses ribbons in as state. Using the HFQS program the distributions of the magnetic hyperfine P(H fields were determined for spectra smoothed in this way, employing the Hesse-Rübartsch method. Observations of the structure of powders were made on the OPTON DSM-940 scanning electron microscope. The diffraction examinations and examinations of thin foils were made on the JEOL JEM 200CX transmission electron microscope equipped in equipped with the EDS LINK ISIS X- ray energy dispersive spectrometer made by Oxford. Graphical analyses of the obtained X-ray diffraction patterns, as well as of the HC=f(TA relationship were made using the MICROCAL ORIGIN 6.0 program.Findings: The analysis of the structure and magnetic properties test results of the HITPERM powders alloy Co68Fe4Mo1Si13.5B13.5 obtained in the high-energy ball of milling process proved that the process causes significant decrease in the magnetic properties. The magnetic properties of this material and structure and may be improved by means of a proper choice of parameters of this process as well as the final thermal treatment.Research limitations/implications: For the soft magnetic powder material, further magnetical, composition examinations and structure are planed.Practical implications: Feature an alternative to solid alloys are the amorphous and nanocrystalline metal powders obtained by milling of metallic glasses and make it possible to obtain the ferromagnetic nanocomposites, whose dimensions and shape can be freely formed.Originality/value: The paper presents results of influence of parameters

  16. Methods for characterizing magnetic footprints of perpendicular magnetic recording writer heads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shaoping, E-mail: shaoping.li@wdc.com; Lin, Ed; George, Zach; Terrill, Dave; Mendez, H.; Santucci, J.; Yie, Derek [Western Digital Corp., 44100 Osgood Road, Fremont, California 94539 (United States)

    2014-05-07

    In this work, the magnetic footprints, along with some of its dynamic features in recording process, of perpendicular magnetic recording writer heads have been characterized by using three different techniques. Those techniques are the spin-stand stationary footprint technique, the spin-stand dynamic footprint technique, and the coherent writing technique combined with magnetic force microscope imaging method. The characteristics of those techniques have been compared to one another. It was found experimentally that the spin-stand stationary method could not precisely catch some peculiar recording dynamics of the write heads in certain conditions. The advantages and disadvantages among all those techniques are also examined and discussed in detail.

  17. ABSORBENT MATERIALS BASED ON KRAFT PULP: PREPARATION AND MATERIAL CHARACTERIZATION

    Directory of Open Access Journals (Sweden)

    Fredrik Wernersson Brodin,

    2012-02-01

    Full Text Available Today, petroleum-based superabsorbents are widely used, but interest in renewable alternatives is on the rise. This study presents two wood-based absorbent materials suitable for various absorption applications as an alternative to petroleum-based products. Never-dried bleached kraft pulp was treated with TEMPO-oxidation, and new carboxylate and aldehyde groups were introduced. It was found that the aldehyde groups contributed to the wet integrity of the absorbent materials, possibly by the formation of hemiacetal bonds. After oxidation, the pulp fibers were gradually disintegrated, and size analysis showed that the disintegration rate was enhanced by an increase in the charge of the oxidant. Freeze drying produced a porous foam with a large surface area that enabled a rapid absorption rate as well as a reasonably high absorption capacity even for absorption under load. Air drying formed a compact film with a slow absorption rate but with a high final capacity for absorption.

  18. Analysis of ringing due to magnetic core materials used in pulsed nuclear magnetic resonance applications

    Science.gov (United States)

    Prabhu Gaunkar, Neelam; Nlebedim, Cajetan; Hadimani, Ravi; Bulu, Irfan; Song, Yi-Qiao; Mina, Mani; Jiles, David

    Oil-field well logging instruments employ pulsed nuclear magnetic resonance (NMR) techniques and use inductive sensors to detect and evaluate the presence of particular fluids in geological formations. Acting as both signal transmitters and receivers most inductive sensors employ magnetic cores to enhance the quality and amplitude of signals recorded during field measurements. It is observed that the magnetic core also responds to the applied input signal thereby generating a signal (`ringing') that interferes with the measurement of the signals from the target formations. This causes significant noise and receiver dead time and it is beneficial to eliminate/suppress the signals received from the magnetic core. In this work a detailed analysis of the magnetic core response and in particular loading of the sensor due to the presence of the magnetic core is presented. Pulsed NMR measurements over a frequency band of 100 kHz to 1MHz are used to determine the amplitude and linewidth of the signals acquired from different magnetic core materials. A lower signal amplitude and a higher linewidth are vital since these would correspond to minimal contributions from the magnetic core to the inductive sensor response and thus leading to minimized receiver dead time.

  19. Sorption behavior of cesium from aqueous solution on magnetic hexacyanoferrate materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hengxuan; Zhao, Xuan, E-mail: zhxinet@tsinghua.edu.cn; Wei, Jiying; Li, Fuzhi

    2014-08-15

    Highlights: • A novel pathway of synthesizing magnetic hexacyanoferrate material was developed. • The synthesized material can offer a high capacity for sorption of cesium. • The material can offer a fast removal of cesium in kinetic performance. • The fine M-PTH particle can be easily separated from wastewater for recirculation. - Abstract: The rapid development of the nuclear power plant in China leads to increasing attention to the treatment of low-level radioactive wastewater (LLRW). One of possibilities is the application of inorganic adsorbent like potassium titanium hexacyanoferrate (PTH), which can exhibit the effective adsorption of cesium. In this paper, the PTH material was optimized by means of being loaded on magnetite substrate. The synthesized material (magnetic PTH, M-PTH), with a particle size of less than 100 nm, can offer a high capacity and favorable kinetic performance, however, without difficulties of separation from the LLRW due to its magnetic characterizations. The batch experiments demonstrate that cesium sorption isotherm of M-PTH coincide well with Langmuir model. The calculated capacity amounts to 0.517 mmol/g, approximately 1.5 times the capacity of zeolite materials. The sorption process follows the pseudo-second-order sorption model. In the initial phase the rate-controlling step is intraparticle diffusion. With the Cs accumulation on the particle surface, external diffusion performs an important role together with intraparticle diffusion.

  20. Numerical Modeling of Multi-Material Active Magnetic Regeneration

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Engelbrecht, Kurt; Bahl, Christian Robert Haffenden;

    2009-01-01

    Magnetic refrigeration is a potentially environmentally-friendly alternative to vapour compression technology that is presented in this paper. The magnetocaloric effect in two magnetocaloric compounds in the La(Fe,Co,Si)13 series is presented in terms of their adiabatic temperature change and the...... specific heat as a function of temperature at constant magnetic field. A 2.5-dimensional numerical model of an active magnetic regenerative (AMR) refrigerator device is presented. The experimental AMR located at Risø DTU has been equipped with a parallel-plate based regenerator made of the two materials....... Experimental zero heat-load temperature spans are presented for different operating conditions and the results are compared to predictions of the numerical model. It is concluded that the model reproduces the experimental tendencies and when including thermal parasitic losses to ambient and the predictions...

  1. Characterization of integrated circuit packaging materials

    CERN Document Server

    Moore, Thomas

    1993-01-01

    Chapters in this volume address important characteristics of IC packages. Analytical techniques appropriate for IC package characterization are demonstrated through examples of the measurement of critical performance parameters and the analysis of key technological problems of IC packages. Issues are discussed which affect a variety of package types, including plastic surface-mount packages, hermetic packages, and advanced designs such as flip-chip, chip-on-board and multi-chip models.

  2. Spectral Characterization of Bright Materials on Vesta

    Science.gov (United States)

    Capaccioni, Fabrizio; DeSanctis, M. C.; Ammannito, E.; Li, Jian-Yang; Longobardo, A.; Mittlefehldt, David W.; Palomba, E.; Pieters, C. M.; Schroeder, S. E.; Tosi, F.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.

    2012-01-01

    The surface of Vesta, as observed by the camera and imaging spectrometer onboard the Dawn spacecraft, displays large surface diversity in terms of its geology and mineralogy with noticeably dark and bright areas on the surface often associated with various geological features and showing remarkably different forms. Here we report our initial attempt to spectrally characterize the areas that are distinctively brighter than their surroundings.

  3. Synthesis and characterization of a new photoluminescent material, tris-[1-10 phenanthroline] aluminium

    Science.gov (United States)

    Kumar, Rahul; Dvivedi, Avanish; Bhargava, Parag

    2016-05-01

    A new photoluminescent material namely tris-[1-10 Phenanthroline] Aluminium Al(Phen)3 has been synthesized and characterized. This material was characterized by fourier transform infrared spectroscopy (FTIR),nuclear magnetic resonance (NMR),mass spectroscopy, thermal gravimetric analysis (TGA),ultraviolet-visible spectroscopy(UV) and photoluminescence (PL). This material shows thermal stability up to 300°C. This material showed absorption maxima at 352nm which may be attributed to the moderate energy (π-π*) transition. Photoluminescence spectra for this material showed the most intense peak at 423 nm and the time resolved photoluminescence spectra showed two life time components. The decay times of the first and second component were 1.4ns and 4.8 ns respectively.

  4. Method for material characterization in a non-anechoic environment

    Science.gov (United States)

    Pometcu, L.; Sharaiha, A.; Benzerga, R.; Tamas, R. D.; Pouliguen, P.

    2016-04-01

    This paper presents a characterization method for extracting the reflection coefficient of materials and the real part of their permittivity. The characterization is performed in a real environment, as opposed to the classical measurement methods that require an anechoic chamber. In order to reduce the effects of the multipath propagation, a free space bistatic measurement was performed at different distances material-antennas in far field. By using a Teflon sample and a commercial absorbing material sample, measurements have been performed in order to validate the characterization technique.

  5. Characterization of Materials by Vibration Technique

    Directory of Open Access Journals (Sweden)

    Mohd Hilman Mohd Akil Tan

    2011-12-01

    Full Text Available This paper presents an experimental investigation of two different kinds of plates of materials namely glass and stainless steel by experimental modal analysis. The materials are excited by an impact hammer to perform resonant vibration where the characteristics of the resonance are acquired. One most important characteristic is the natural frequency where it is known that different material having undergone resonant vibration exhibit different specific natural frequencies to it. The natural frequencies and corresponding mode shapes are used as the parameters of determining the structural properties of these materials. The vibration analysis is done using the LMS instruments and software where Frequency Response Function (FRF measurement technique is employed in determining the natural frequencies. The structural properties are established based on the obtained natural frequencies and geometries of the materials using the expression from available literature. The elastic moduli obtained for glass and stainless steel are 66.08 Gpa and 193.26 GPa.ABSTRAK: Kertas ini membentangkan kajian mengenai dua bahan plat yang berbeza iaitu kaca dan keluli tahan karat dengan menggunakan analisis ragaman eksperimental. Getaran resonans dijalankan dengan menguja bahan-bahan tersebut dengan tukul hentaman dimana ciri-ciri tertentu diperolehi. Frekuensi asli merupakan satu daripada ciri utama, dimana ianya diketahui bahawa bahan yang berbeza akan mengalami getaran resonans yang menghasilkan frekuensi asli tertentu. Frekuensi asli dan bentuk ragam yang berpadanan digunakan sebagai parameter dalam menentukan sifat-sifat struktur bahan ini. Analisis getaran dijalankan dengan menggunakan peralatan LMS dan teknik ukuran perisian Fungsi Frekuensi Sambutan (Frequency Response Function (FRF untuk menentukan frekuensi asli. Sifat-sifat struktur ditentukan berdasarkan frekuensi asli dan bahan geometri, yang diperolehi daripada pengungkapan bahan sumber bacaan yang sedia

  6. Nuclear magnetic resonance studies of materials for spintronic applications

    International Nuclear Information System (INIS)

    Since its discovery in liquids and also in solid matter in 1946, nuclear magnetic resonance (NMR) has been widely established as a standard tool for structural analysis of a wide range of materials. This review outlines recent NMR studies on materials considered to be useful in spintronic applications. Spintronics is a new research field which combines the use of both the charge and the spin of an electron as information carriers, which promises distinct advantages over conventional electronics which makes use only of the charge of electrons. A successful application of materials in spintronic devices requires a detailed knowledge of the interplay between the structure and the magnetic and electronic properties on an atomic scale. NMR probes the local environments of the active nuclei. This local character of NMR arises from local contributions to the hyperfine field, namely, the transferred field which depends on the nearest neighbour atoms and their magnetic moments. This enables NMR to study the structural properties of bulk samples as well as of thin films of spin polarized materials. Moreover, NMR spectroscopy also provides an indirect tool to measure the density of states of spin polarized materials via a measurement of the temperature dependence of the spin-lattice relaxation time. This review starts with an introduction into the basic concepts of NMR followed by a description of the important aspects of a pulsed NMR experiment. Thereafter, information obtained by an NMR experiment is addressed. In the subsequent main part, selected recent NMR studies (published roughly after the year 2000) of materials for spintronic applications are presented including NMR studies of, for example, Co thin films, Heusler compounds, double perovskites and pyrites. (topical review)

  7. Influence of eddy currents on magnetic hysteresis loops in soft magnetic materials

    Science.gov (United States)

    Szczygłowski, Jan

    2001-01-01

    In this paper an attempt has been made to extend the Jiles and Atherton (J-A) quasi-static hysteresis model to describe magnetisation of a material with an alternating magnetic field. In low - industrial - and medium frequency of magnetic field it is possible to ignore the magnetic relaxation and resonance. The field penetration is assumed to be uniform through the material. The influence of eddy currents on the hysteresis loop could be considered and calculated using the method of successive reactions of eddy currents, where a reaction is an additional magnetic field, called reaction Hd, induced in the material by the eddy currents according to rot J= γ∂ B/∂ t where γ is the electrical conductivity. The reaction field Hd was added to the basic field H0∝ Iz1, where I is the current intensity in the magnetising coil of z1 number of windings. By solving the J-A equation for the magnetic field Hw= H0+ Hd it has achieved an extension of the hysteresis loop at an increased frequency of the current, caused by increased losses of the eddy currents. At the frequency f→0 Hz , the hysteresis loop approaches the shape of the quasi-static one.

  8. Hybrid materials: Magnetite-Polyethylenimine-Montmorillonite, as magnetic adsorbents for Cr(VI) water treatment.

    Science.gov (United States)

    Larraza, Iñigo; López-Gónzalez, Mar; Corrales, Teresa; Marcelo, Gema

    2012-11-01

    Hybrid materials formed by the combination of a sodium rich Montmorillonite (MMT), with magnetite nanoparticles (40 nm, Fe(3)O(4) NPs) coated with Polyethylenimine polymer (PEI 800 g/mol or PEI 25000 g/mol) were prepared. The intercalation of the magnetite nanoparticles coated with PEI among MMT platelets was achieved by cationic exchange. The resulting materials presented a high degree of exfoliation of the MMT sheets and a good dispersion of Fe(3)O(4) NPs on both the surface and among the layers of MMT. The presence of amine groups in the PEI structure not only aids the exfoliation of the MMT layers, but also gives to the hybrid material the necessary functionality to interact with heavy metals. These hybrid materials were used as magnetic sorbent for the removal of hexavalent chromium from water. The effect that pH, Cr(VI) concentration, and adsorbent material composition have on the Cr(VI) removal efficiency was studied. A complete characterization of the materials was performed. The hybrid materials showed a slight dependence of the removal efficiency with the pH in a wide range (1-9). A maximum amount of adsorption capacity of 8.8 mg/g was determined by the Langmuir isotherm. Results show that these hybrid materials can be considered as potential magnetic adsorbent for the Cr(VI) removal from water in a wide range of pH. PMID:22841705

  9. Neutron and gamma irradiation effects on organic insulating materials for fusion magnets

    International Nuclear Information System (INIS)

    Available low-temperature neutron and gamma irradiation data for organic insulating materials are collected and compared with room temperature data. Only the most promising polymers in terms of mechanical strength for magnet insulation are taken into account. For characterization and comparison of different materials the 75% dose is used, i.e. the dose, where the mechanical strength is reduced by 25%, and 75% is retained. For room temperature special prepared polyimide and epoxy materials reinforced with glass fibre retained 75% of the mechanical strength up to a dose of 7x107 Gy. For 5 K irradiation the best epoxy material retained the 75% dose up to 1x107 Gy, the best polyimide material up to 1x108 Gy. (orig.)

  10. Non-destructive magnetic adaptive testing of ferromagnetic materials

    Czech Academy of Sciences Publication Activity Database

    Tomáš, Ivan

    2003-01-01

    Roč. 268, - (2003), s. 178-185. ISSN 0304-8853 R&D Projects: GA ČR GA101/02/0236; GA AV ČR KSK1010104 Institutional research plan: CEZ:AV0Z1010914 Keywords : non-destructive testing * ferromagnetic material * construction steel * differencial permeability * Preisach evolution Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.910, year: 2003

  11. Magnetic resonance as a technique to magnetic biosensors characterization in Neocapritermes opacus termites

    Science.gov (United States)

    de Oliveira, J. F.; Wajnberg, E.; Esquivel, D. M. S.; Alves, O. C.

    2005-07-01

    This experimental study quantitatively correlates the saturation magnetization obtained from hysteresis curves (SQUID measurements) to the second integral of the magnetic resonance (MR) spectra of Neocapritermes opacus termites. Termites were submitted to an iron private diet, feeding them with pure cellulose for up to four days. This diet cleans their guts of ingested detrital material, eliminating non-biogenic soil-derived magnetite from the ensuing analyses. A clear relation between total magnetic moment (emu) from SQUID measurements and the signal intensity (absorption area) from MR is given.

  12. Practical applications of nondestructive materials characterization

    Science.gov (United States)

    Green, Robert E., Jr.

    1992-10-01

    Nondestructive evaluation (NDE) techniques are reviewed for applications to the industrial production of materials including microstructural, physical, and chemical analyses. NDE techniques addressed include: (1) double-pulse holographic interferometry for sealed-package leak testing; (2) process controls for noncontact metals fabrication; (3) ultrasonic detections of oxygen contamination in titanium welds; and (4) scanning acoustic microscopy for the evaluation of solder bonds. The use of embedded sensors and emerging NDE concepts provides the means for controlling the manufacturing and quality of quartz crystal resonators, nickel single-crystal turbine blades, and integrated circuits. Advances in sensor technology and artificial intelligence algorithms and the use of embedded sensors combine to make NDE technology highly effective in controlling industrial materials manufacturing and the quality of the products.

  13. Material characterization of rigid foam insulation at low temperature

    Science.gov (United States)

    Barrios, Matthew

    There is a continuing need for improved rigid foam insulation, particularly for cryogenic storage aboard aerospace vehicles. The present work is a material characterization of spray-on foam insulation used on the Space Shuttle External Tank. The characterization includes imaging and measurements of thermal conductivity, ultimate tensile strength, and moisture absorption. Thermal conductivity measurements are the main focus of the present work, as it is the most relevant property to insulation performance. A novel apparatus was developed to measure the thermal conductivity of rigid foam at temperatures ranging from 20 K to 300 K with a DeltaT of 10 K between the sides of the foam sample. The effective thermal conductivity of three samples of NCFI 24-124 foam insulation was measured over the full temperature range. Additionally, the effects of different residual gases and moisture absorption on the thermal conductivity of the foam were studied. The data were compared to data from the literature and to mathematical models developed to predict the thermal conductivity. The data show that gas condensation can play a significant role in the thermal conductivity of the foam at low temperature. Moisture absorption can occur in the foam in application when cryogenic fuel is filled into a tank which sits in a warm, humid environment. An apparatus was developed to subject foam samples to these conditions. The moisture content in the samples was then measured. The samples were then imaged using the 900 MHz NMR magnet at the National High Magnetic Field Laboratory to determine the location of the water within the foam. Samples conditioned for 9 hours exhibited a 50% weight increase, and samples conditioned for 69 hours exhibited a 284% weight increase. The NMR images showed that the moisture collects first near the warm side of the foam, and permeates through the foam over time. However, the moisture appears to not collect near the knit lines (areas between sprayed layers of

  14. Structural characterization of macroscopic single-walled carbon nanotube materials

    Science.gov (United States)

    Zhou, Wei

    In this thesis, we studied the structural properties of macroscopic materials of single-walled carbon nanotubes (SWNTs) in the form of fibers, films and suspensions. We characterized the preferred orientations in partially aligned SWNT fibers and films, combining x-ray fiber diagram and polarized Raman scattering. Our texture model consists of an aligned fraction, characterized by the angular distribution width of tube axes, plus a completely unaligned fraction. For neat fibers extruded from SWNT/superacid suspensions through a small orifice, the distribution width and the aligned fraction both improve with decreasing orifice diameter. For magnetic field-aligned SWNT films deposited from surfactant suspensions, the aligning effects of deposition and external magnetic field force in the film plane are additive, the out-of-plane mosaic being narrower than the in-plane one. SWNTs dispersed in superacid or aqueous surfactant solutions are precursors for many applications. In oleum, SWNTs can be charged and protonated by H 2SO4 molecules. X-ray scattering indicates that H2SO 4 molecules align along nanotube axes to form cylindrical shells wrapped around nanotubes. This finding establishes the validity of a long-standing important but still debated physical chemistry concept, "structured solvent shells surrounding dissolved ions". Differential scanning calorimetry confirms that the partly ordered H2SO4 molecules are a new phase, with distinct freezing/melting behavior. X-ray scattering at low temperature further shows that crystallization of the bulk-like acid surrounding the structured shells is templated by the SWNTs. The specific orientation of the acid crystallites provides solid evidence for direct protonation of SWNT. We studied the morphologies of SWNT suspensions using small-angle neutron scattering. We observed rigid rod behavior from SWNTs dispersed in water using sodium dodecylbenzene sulfonate surfactant, suggesting that SWNTs exist mainly as individual tube

  15. Using Raman spectroscopy to characterize biological materials.

    Science.gov (United States)

    Butler, Holly J; Ashton, Lorna; Bird, Benjamin; Cinque, Gianfelice; Curtis, Kelly; Dorney, Jennifer; Esmonde-White, Karen; Fullwood, Nigel J; Gardner, Benjamin; Martin-Hirsch, Pierre L; Walsh, Michael J; McAinsh, Martin R; Stone, Nicholas; Martin, Francis L

    2016-04-01

    Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information. Many materials have characteristic Raman spectra, which means that Raman spectroscopy has proven to be an effective analytical approach in geology, semiconductor, materials and polymer science fields. The application of Raman spectroscopy and microscopy within biology is rapidly increasing because it can provide chemical and compositional information, but it does not typically suffer from interference from water molecules. Analysis does not conventionally require extensive sample preparation; biochemical and structural information can usually be obtained without labeling. In this protocol, we aim to standardize and bring together multiple experimental approaches from key leaders in the field for obtaining Raman spectra using a microspectrometer. As examples of the range of biological samples that can be analyzed, we provide instructions for acquiring Raman spectra, maps and images for fresh plant tissue, formalin-fixed and fresh frozen mammalian tissue, fixed cells and biofluids. We explore a robust approach for sample preparation, instrumentation, acquisition parameters and data processing. By using this approach, we expect that a typical Raman experiment can be performed by a nonspecialist user to generate high-quality data for biological materials analysis. PMID:26963630

  16. Characterization of polyetheretherketone-hydroxyapatite nanocomposite materials

    International Nuclear Information System (INIS)

    Research highlights: → PEEK-HA composite materials have been successfully produced. → The tensile strength of the composites is 5% higher than that of pure PEEK. → HA nanoparticles show strong bonding to PEEK matrix. - Abstract: Polyetheretherketone-hydroxyapatite nanocomposite materials are investigated for the purpose of improving the bonding between polyetheretherketone (PEEK) matrix and hydroxyapatite (HA) fillers since their debonding deteriorates the otherwise superior antifatigue properties of PEEK materials. The nanocomposites are successfully produced by incorporating lab-prepared HA nanoparticles, up to 15.0 vol%, to PEEK matrix via a compounding and injection molding process. The microstructures of the composite samples are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystallization and phase structure of the composites are examined by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements. The mechanical properties of the composites are evaluated, and their tensile strength reaches 98 MPa at 5.0 vol% HA. Most importantly the study suggests that there is no debonding occurring between the well-dispersed HA nanoparticles and PEEK matrix, which provides a promising way to overcome the debonding issue of the PEEK-HA composites.

  17. Improved Electrical Insulation of Rare Earth Permanent Magnetic Materials With High Magnetic Properties

    Institute of Scientific and Technical Information of China (English)

    CHANG Ying; WANG Da-peng; LI Wei; PAN Wei; YU Xiao-jun; QI Min

    2009-01-01

    Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows:(1) Sm2TM17: Br=0.62 T, jHc=803.7 kA/m, (BH)m= The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field.

  18. Magnetic nano-grains from a non-magnetic material: a possible explanation

    International Nuclear Information System (INIS)

    Based on positive semidefinite operator properties, an exact ground state solution is deduced for a 2D Hubbard model with periodic boundary conditions on small samples. The obtained ferromagnetic behavior is used as a possible explanation of the ferromagnetism occurring in nano-samples made of non-magnetic but metallic materials

  19. Epitaxial growth and characterization of layered magnetic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Bertacco, R. [LNESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, Como (Italy); Cantoni, M. [LNESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, Como (Italy); Riva, M. [LNESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, Como (Italy); Tagliaferri, A. [LNESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, Como (Italy); Ciccacci, F. [LNESS, Dipartimento di Fisica del Politecnico di Milano, via Anzani 52, Como (Italy)]. E-mail: franco.ciccacci@fisi.polimi.it

    2005-12-15

    We describe the construction and operation of an ultrahigh-vacuum system devoted to the study of layered magnetic nanostructures. The apparatus includes two growth chambers, where specimens nanostructured along the direction of growth (heterostructures, nanometric and subnanometric thin films and multilayers) are deposited either by molecular beam epitaxy or pulsed laser deposition, and a measurement chamber, where they are analyzed in situ by a variety of electron spectroscopies. Magnetic characterization is obtained by spin resolved inverse photoemission spectroscopy and magneto optical Kerr effect technique. Vacuum transfer towards other experimental facilities is also available. As examples of application, results from half metallic magnetic oxides, such as magnetite (Fe{sub 3}O{sub 4}) and manganite (La{sub 2/3}Sr{sub 1/3}MnO{sub 3}) thin films, and ferromagnet/semiconductor interfaces (Fe/Ge(0 0 1)) are also reported.

  20. Alternative material study for heat assisted magnetic recording transducer application

    Science.gov (United States)

    Xu, B. X.; Cen, Z. H.; Hu, J. F.; Tsai, J. W. H.

    2015-05-01

    In heat assisted magnetic recording (HAMR), optical near field transducer (NFT) is a key component. Au is currently used as NFT material because of its strong surface plasmon effect. Due to the soft property of Au material, reliability of Au NFT becomes a key issue for realizing HAMR production. In this paper, the possibility of alternative materials, including transition metal nitrides (TMNs) and transparent conducting oxides (TCOs) to replace Au is studied. The results show that all of the listed TMN and TCO materials can meet the mechanical requirements at room temperature in terms of hardness and thermal expansion. An optical model, which includes optical waveguide, NFT and FePt media, is used to simulate NFT performances. The results indicate that the resonant wavelengths for NFT with TCO materials are longer than 1500 nm, which is not suitable for HAMR application. TMN materials are suitable for NFT application at wavelength band of around 800 nm. But the NFT efficiency is very low. ZrN is the best material among TMN materials and the efficiency of ZrN NFT is only 13% of the Au NFT's efficiency. Reducing refractive index (n) and increasing extinction coefficient (k) will both lead to efficiency increase. Increasing k contributes more in the efficiency increase, while reducing n has a relatively low NFT absorption. For materials with the same figure of merit, the NFT with larger k material has higher efficiency. Doping materials to increase the material conduction electron density and growing film with larger size grain may be the way to increase k and reduce n.

  1. Development and characterization of aluminum stranded water cooled conductor for rapid cycling synchrotron magnets

    International Nuclear Information System (INIS)

    Magnet coils of rapid cycling synchrotron are subjected to time varying magnetic fields and a special water cooled stranded conductor is preferred for making magnet coils to reduce eddy current losses, magnetic field inhomogeneity and operating costs of magnets. A continuous length (∼ 50 m) aluminum stranded water cooled conductor is indigenously developed. Five stranded magnet coils are wound and epoxy resin impregnated as per the technical requirements. The stranded conductor magnet coils are assembled with a laminated dipole magnet core for their electrical characterization. The development of water cooled aluminum stranded conductor, characterization of stranded magnet coils will be discussed in this paper. (author)

  2. Characterization of the GEM foil materials

    CERN Document Server

    Benussi, L; Saviano, G; Muhammad, S; Piccolo, D; Raffone, G; Caponero, M; Passamonti, L; Pierluigi, D; Russo, A; Primavera, F; Cerbelli, S; Lalli, A; Valente, M; Ferrini, M; Teissandier, B; Taborelli, M; Parvis, M; Grassini, S; Tirilló, J; Sarasini, F; Franchi, A V

    2015-01-01

    Systematic studies on the GEM foil material are performed to measure the moisture diffusion rate and saturation level. These studies are important because the presence of this compound inside the detector's foil can possibly change its mechanical and electrical properties and, in such a way, the detector performance can be affected. To understand this phenomenon, a model is developed with COMSOL Multhiphysics v. 4.3, which described the adsorption and diffusion within the geometry of GEM foil, the concentration profiles and the time required to saturate the foil. The COMSOL model is verified by experimental observations on a GEM foil sample. This note will describe the model and its experimental verification results.

  3. Preparation and characterization of magnetic Fe3O4–chitosan nanoparticles loaded with isoniazid

    International Nuclear Information System (INIS)

    A novel and simple method has been proposed to prepare magnetic Fe3O4–chitosan nanoparticles loaded with isoniazid (Fe3O4/CS/INH nanocomposites). Efforts have been made to develop isoniazid (INH) loaded chitosan (CS) nanoparticles by ionic gelation of chitosan with tripolyphosphate (TPP). The factors that influence the preparation of chitosan nanoparticles, including the TPP concentration, the chitosan/TPP weight ratio and the chitosan concentration on loading capacity and encapsulation efficiency of chitosan nanoparticles were studied. The magnetic Fe3O4 nanoparticles were prepared by co-precipitation method of Fe2+ and Fe3+. Then the magnetic Fe3O4/CS/INH nanocomposites were prepared by ionic gelation method. The magnetic Fe3O4 nanoparticles and magnetic Fe3O4/CS/INH nanocomposites were characterized by XRD, TEM, FTIR and SQUID magnetometry. The in vitro release of Fe3O4/CS/INH nanocomposites showed an initial burst release in the first 10 h, followed by a more gradual and sustained release for 48 h. It is suggested that the magnetic Fe3O4/CS/INH nanocomposites may be exploited as potential drug carriers for controlled-release applications in magnetic targeted drugs delivery system. - Highlights: • A novel and simple method for preparation of nanocomposites for biomedicine. • All the materials are non-toxic and biocompatibility. • This paper gives systematic study of the nanocomposites in biomedicine

  4. Applications of high throughput (combinatorial) methodologies to electronic, magnetic, optical, and energy-related materials

    Science.gov (United States)

    Green, Martin L.; Takeuchi, Ichiro; Hattrick-Simpers, Jason R.

    2013-06-01

    High throughput (combinatorial) materials science methodology is a relatively new research paradigm that offers the promise of rapid and efficient materials screening, optimization, and discovery. The paradigm started in the pharmaceutical industry but was rapidly adopted to accelerate materials research in a wide variety of areas. High throughput experiments are characterized by synthesis of a "library" sample that contains the materials variation of interest (typically composition), and rapid and localized measurement schemes that result in massive data sets. Because the data are collected at the same time on the same "library" sample, they can be highly uniform with respect to fixed processing parameters. This article critically reviews the literature pertaining to applications of combinatorial materials science for electronic, magnetic, optical, and energy-related materials. It is expected that high throughput methodologies will facilitate commercialization of novel materials for these critically important applications. Despite the overwhelming evidence presented in this paper that high throughput studies can effectively inform commercial practice, in our perception, it remains an underutilized research and development tool. Part of this perception may be due to the inaccessibility of proprietary industrial research and development practices, but clearly the initial cost and availability of high throughput laboratory equipment plays a role. Combinatorial materials science has traditionally been focused on materials discovery, screening, and optimization to combat the extremely high cost and long development times for new materials and their introduction into commerce. Going forward, combinatorial materials science will also be driven by other needs such as materials substitution and experimental verification of materials properties predicted by modeling and simulation, which have recently received much attention with the advent of the Materials Genome

  5. New Techniques in Characterization of Ferroelectric Materials

    Science.gov (United States)

    Sehirlioglu, Alp

    2008-01-01

    Two new techniques have been developed to characterize Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) based ferroelectric single crystals: (i) electro-thermal imaging, and (ii) single crystal x-ray diffraction in the transmission mode. (i) Electro-thermal imaging is a remote sensing technique that can detect the polarization direction and poling state of a whole crystal slice. This imaging technique utilizes an IR camera to determine the field induced temperature change and does not require any special or destructive sample preparation. In the resulting images it is possible to distinguish regions of 180 deg domains. This powerful technique can be used remotely during poling to determine the poling state of the crystal to avoid over-poling that can result in inferior properties and/or cracking of the crystals. Electro-thermal imaging produced the first direct observations of polarization rotation. Under bipolar field, the domains near the corners were the first to switch direction. As the field increased above the coercive field, domains at the center part of the crystals switched direction. (ii) X-ray diffraction in the transmission mode has long been used in structure determination of organic crystals and proteins; however, it is not used much to characterize inorganic systems. 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 single crystals were examined by this XRD technique for the first time, and a never-before-seen super-lattice was revealed with a doubling of the unit cell in all three directions, giving a cell volume eight times that of a traditional perovskite unit cell. The significance of the super-lattice peaks increased with poling, indicating a structural contribution to ordering. Lack of such observations by electron diffraction in the transmission electron microscope examinations suggests the presence of a bulk effect.

  6. Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material

    International Nuclear Information System (INIS)

    Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe3O4 nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g−1 and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. - Highlights: • Bacterial cellulose/magnetite nanocomposites with high incorporation degree of nanoparticles. • Magnetite nanoparticles well adhered to the surface of bacterial cellulose nanofibers. • A saturation magnetization of the nanoparticles in the BC pellicles of about 60 emu g−1. • Flexible membranes with high super-paramagnetic characteristic

  7. One-pot synthesis of magnetic hybrid materials based on ovoid-like carboxymethyl-cellulose/cetyltrimethylammonium-bromide templates

    International Nuclear Information System (INIS)

    A novel one-pot synthetic procedure to obtain magnetic hybrid nanostructured materials (HNM), based on magnetic spinel-metal-oxide (SMO) nanoparticles stabilized in ovoid-like carboxymethyl-cellulose (CMC)/cetyltrimethylammonium-bromide (CTAB) templates, is reported. The HNM were synthesized from the controlled hydrolysis of inorganic salts of Fe (II) and Fe (III) into aqueous dissolutions of CMC and CTAB. The synthesized HNM were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and static magnetic measurements. The experimental evidence suggests that, due to the competition between CTAB molecules and SMO nanoparticles to occupy CMC intermolecular sites nearby to its carboxylate functional groups, the size of both, SMO nanoparticles and ovoid-like CMC/CTAB templates can be tuned, varying the CTAB:SMO weight ratio. Moreover, it was found that the magnetic response of the HNM depends on the confinement degree of the SMO nanoparticles into the CMC/CTAB template. Hence, their magnetic characteristics can be adjusted controlling the size of the template, the quantity and distribution of the SMO nanoparticles within the template and their size. - Graphical abstract: Display Omitted - Highlights: • The synthesis of magnetic hybrid materials is reported. • The hybrid materials were synthesized following a novel one-pot procedure. • The magnetic nanoparticles were stabilized in ovoid-like templates. • The size of the templates was tuned adjusting nanoparticles weight content. • The magnetic properties of hybrid materials depend on the size of the template

  8. Impact damage characterization of composite materials

    Science.gov (United States)

    Korkmaz, Yesim

    2002-04-01

    Impact damage in structural composites depends on their material properties, component geometry and a variety of impact parameters and experimental determination of their detailed characteristics requires prohibitively large test matrices. The effects of some of these parameters can be understood through simulation models that complement experimental results. In this dissertation a series of finite element models are developed using MSC/NASTRAN for calculating contact laws and progressive damage (e.g., matrix cracking, delamination and fiber break) in graphite/epoxy laminates subject to low and intermediate velocity impact. The validity of the computational models is supported by theoretical calculations involving idealized cases. The effects of laminate geometry as well as the impact parameters on the nature and degree of damage are studied. The global force-time and displacement-time responses of the laminate during impact are also studied. The results of this research can be used for damage growth prediction in composite structural components subject to impact loads.

  9. Characterization of advanced preprocessed materials (Hydrothermal)

    Energy Technology Data Exchange (ETDEWEB)

    Rachel Emerson; Garold Gresham

    2012-09-01

    The initial hydrothermal treatment parameters did not achieve the proposed objective of this effort; the reduction of intrinsic ash in the corn stover. However, liquid fractions from the 170°C treatments was indicative that some of the elements routinely found in the ash that negatively impact the biochemical conversion processes had been removed. After reviewing other options for facilitating ash removal, sodium-citrate (chelating agent) was included in the hydrothermal treatment process, resulting in a 69% reduction in the physiological ash. These results indicated that chelation –hydrothermal treatment is one possible approach that can be utilized to reduce the overall ash content of feedstock materials and having a positive impact on conversion performance.

  10. Non-destructive evaluation of mechanical properties of magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kankolenski, K.P.; Hua, S.Z.; Yang, D.X.; Hicho, G.E.; Swartzendruber, L.J.; Zang, Z.; Chopra, H.D.

    2000-07-01

    A magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

  11. Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys

    International Nuclear Information System (INIS)

    Highlights: • Small W additions (up to 9 at.%) to the Co35Fe65 binary system. • Electrodeposited Co–Fe–W alloys characterization by XRD, SEM, TEM, Mössbauer spectroscopy and magnetic measurements. • Production of Co–Fe–W alloys with low values of coercivity and high saturation magnetization. • Potential materials for applications in magnetic devices such as read/write heads and hard disks. - Abstract: Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys, containing small amounts of W (up to 9 at.%), were performed using X-ray diffractometry, scanning (SEM) and transmission (TEM) electron microscopy, Mössbauer spectroscopy and magnetization measurements. Electrodeposited (Co100−xFex)100−yWy films (x = 63–72 at.% Fe, y = 4–9 at.% W) were successfully produced varying the applied cathodic current density (ic) between 0.5 and 10 mA cm−2. X-ray diffraction results revealed a bcc-like structure for all studied compositions with average crystallite size ranging from 16 to 35 nm, as also confirmed by TEM results. SEM images indicated that needle-type morphology is dominant for the deposits containing lower W content (up to 4.5 at.%.), while a cauliflower-type behavior is observed for higher W content deposits. Room temperature Mössbauer spectra indicate the presence of two magnetic species for all samples; one component associated with an ordered Co–Fe–W fraction (crystalline grain core) and a magnetic disordered Co–Fe–W contribution, which can be attributed to the grain boundaries/grain surfaces. Magnetization was observed to be in the film plane along the film direction, except the sample prepared at ic = 10 mA cm−2 that is slightly canted from in- to out-of-plane geometry. Magnetic measurements show high saturation magnetization values accompanied by low coercivity ones for the electrodeposited Co–Fe–W alloys, making these alloys potential materials for applications in magnetic devices

  12. Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys

    Energy Technology Data Exchange (ETDEWEB)

    Noce, R. Della, E-mail: rodrnoce@iq.unesp.br [Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-900 Araraquara, SP (Brazil); Benedetti, A.V.; Magnani, M. [Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-900 Araraquara, SP (Brazil); Passamani, E.C. [Departamento de Física, Universidade Federal do Espírito Santo, 29075-910 Vitória, ES (Brazil); Kumar, H.; Cornejo, D.R. [Instituto de Física, Universidade de São Paulo, USP, 05508-090 São Paulo, SP (Brazil); Ospina, C.A. [Electron Microscopy Laboratory, Brazilian Nanotechnology National Laboratory, 13083-970 Campinas, SP (Brazil)

    2014-10-25

    Highlights: • Small W additions (up to 9 at.%) to the Co{sub 35}Fe{sub 65} binary system. • Electrodeposited Co–Fe–W alloys characterization by XRD, SEM, TEM, Mössbauer spectroscopy and magnetic measurements. • Production of Co–Fe–W alloys with low values of coercivity and high saturation magnetization. • Potential materials for applications in magnetic devices such as read/write heads and hard disks. - Abstract: Structural, morphological and magnetic characterization of electrodeposited Co–Fe–W alloys, containing small amounts of W (up to 9 at.%), were performed using X-ray diffractometry, scanning (SEM) and transmission (TEM) electron microscopy, Mössbauer spectroscopy and magnetization measurements. Electrodeposited (Co{sub 100−x}Fe{sub x}){sub 100−y}W{sub y} films (x = 63–72 at.% Fe, y = 4–9 at.% W) were successfully produced varying the applied cathodic current density (i{sub c}) between 0.5 and 10 mA cm{sup −2}. X-ray diffraction results revealed a bcc-like structure for all studied compositions with average crystallite size ranging from 16 to 35 nm, as also confirmed by TEM results. SEM images indicated that needle-type morphology is dominant for the deposits containing lower W content (up to 4.5 at.%.), while a cauliflower-type behavior is observed for higher W content deposits. Room temperature Mössbauer spectra indicate the presence of two magnetic species for all samples; one component associated with an ordered Co–Fe–W fraction (crystalline grain core) and a magnetic disordered Co–Fe–W contribution, which can be attributed to the grain boundaries/grain surfaces. Magnetization was observed to be in the film plane along the film direction, except the sample prepared at i{sub c} = 10 mA cm{sup −2} that is slightly canted from in- to out-of-plane geometry. Magnetic measurements show high saturation magnetization values accompanied by low coercivity ones for the electrodeposited Co–Fe–W alloys, making these

  13. Microstructural characterisation of sintered soft magnetic nanocomposite materials

    Directory of Open Access Journals (Sweden)

    J. Konieczny

    2013-11-01

    Full Text Available Purpose: The main aim of this work is to investigate microstructure of of sintered soft magnetic nanocomposite materials produced by sintering axially on one side in the ambient atmosphere. Design/methodology/approach: Microstructure observations of 20 mm diameter sintered roller by light microscopy OLYMPUS, scanning electron microscopy OPTON DSM-940 and ZEISS SUPRA 35, and transmission electron microscopy JEOL 3010. The X-ray tests were realized with the use of the XRD 7 SEIFERT-FPM diffractometer equipped with the lamp of the cobalt anode of 35 kV voltage and 30 mA filament current was used. The nanocrystalline ferromagnetic powders were manufactured by high-energy ball milling (8000 SPEX CertiPrep Mixer/Mill of metallic glasses ribbons in as state. The hot pressing process was made on machine “Degussa”. Findings: The analysis of the results enabled determination of the hot pressing parameters on structure of obtained stampings. This is typical of an dispersion strengthened case. Research limitations/implications: For the sintered roller obtained from metallic Co-based amorphous ribbons, further mechanical and magnetic examinations are planed. Practical implications: Conducted research shows that applied technology of sintered roller production allows to obtain good microstructural characteristics. Structure analysis of die stampings of powdered amorphous metallic ribbons is helpful to prepare this material by laboratory methods. Feature an alternative to commercial alloys and composite materials are the amorphous and nanocrystalline metal amorphous ribbons obtained by melt spinning technique and make it possible to obtain the new composite materials with best magnetic properties, which dimensions and shape can be freely formed. Originality/value: The paper presents influence of hot pressing parameters process of metallic powdered ribbons Co77Si11.5B11.5 on structure of obtained die stampings.

  14. Microwave Technologies-- Determination of Magnetic and Dielectric Materials Microwave Properties

    CERN Document Server

    Obol, Mahmut

    2009-01-01

    In this study, four different techniques are presented. 1 Rectangular waveguide measurement technique for normal microwave materials microwave properties such as permeability and permittivity. This technique removed guess parameter and dispersive effect issues of the old waveguide measurement techniques. It projects a new route for determination of any microwave materials magnetic and dielectric properties without using any guesses. 2 Coaxial probe measurement technique for the liquid and biological tissues dielectric permittivity. This coaxial probe technique has an advantage which is to attain the highest reflected signal from the coaxial probe tip, so that it is a fast and very sensitive technique to differentiate lossy materials dielectric permittivity. This technique could be useful non destructive detections for tumors in hospital and non destructive detections for chemical liquids as well. 3 A microstripline measurement technique for oxides microwave measurement at low frequency spectra where the waveg...

  15. Nuclear, chemical, and physical characterization of nuclear materials

    International Nuclear Information System (INIS)

    The goal of nuclear forensics is to establish an unambiguous link between illicitly trafficked nuclear material and its origin. The Los Alamos National Laboratory (LANL) Nuclear Materials Signatures Program has implemented a graded 'conduct of operations' type analysis flow path approach for determining the key nuclear, chemical, and physical signatures needed to identify the manufacturing process, intended use, and origin of interdicted nuclear material. This analysis flow path includes both destructive and non-destructive characterization techniques and has been exercized against different nuclear materials from LANL's special nuclear materials archive. Results obtained from the case study will be presented to highlight analytical techniques that offer the critical attribution information. (author)

  16. Compound semiconductor bulk materials and characterizations, v.2

    CERN Document Server

    Oda, Osamu

    2012-01-01

    This book is concerned with compound semiconductor bulk materials, and has been written for students, researchers and engineers in material science and device fabrication. It provides the elementary and intermediate knowledge of compound semiconductor bulk materials necessary for entry into this field. The first volume described the physical properties, crystal growth technologies, principles of crystal growth, various defects in crystals, characterization techniques and applications, and reviewed various III-V and II-V compound semiconductor materials. In this second volume, other materials a

  17. Characterization of superconducting nanometric multilayer samples for SRF applications: first evidence of magnetic screening effect

    CERN Document Server

    Antoine, C Z; Bouat, S; Jacquot, J-F; Villegier, J-C; Lamura, G; Gurevich, A

    2010-01-01

    Best rf bulk niobium accelerating cavities have nearly reached their ultimate limits at rf equatorial magnetic field H ~ 200 mT close to the thermodynamic critical field Hc. In 2006 Gurevich proposed to use nanoscale layers of superconducting materials with high values of Hc > HcNb for magnetic shielding of bulk niobium to increase the breakdown magnetic field of SC rf cavities 1. Depositing good quality layers inside a whole cavity is rather difficult So as a first step, characterization of single layer coating and multilayers was conducted on high quality sputtered samples by applying the technique used for the preparation of superconducting electronics circuits. The samples were characterized by X-ray reflectivity, dc resistivity (PPMS) and dc magnetization (SQUID) measurements. Dc magnetization curves of a 250 nm thick Nb film have been measured, with and without a magnetron sputtered coating of a single or multiple stack of 15 nm MgO and 25 nm NbN layers. The Nb samples with/without the coatin...

  18. Outgassing tests on materials used in the DIII-D magnetic fusion tokamak

    International Nuclear Information System (INIS)

    In order to achieve high performance plasma discharges in the DIII-D magnetic fusion tokamak, impurity levels must be carefully controlled. Since first wall materials can desorb volatile impurities during these discharges, it is important to characterize and control the outgassing of these materials. An outgassing chamber was built to measure the outgassing properties of various materials used in the DIII-D vessel. The results of pump-down tests performed on ATJ graphite, thin Grafoil reg-sign gaskets, and MgO coaxial cables will be presented. In addition to pumpdown tests it was desired to study the behavior of the materials at temperatures up to 400 C, which is the maximum temperature to which the DIII-D vessel is baked. The station was modified to include independent heating control of the sample and a simple load-lock chamber

  19. Magnetic studies of mesoporous nanostructured iron oxide materials synthesized by one-step soft-templating.

    Science.gov (United States)

    Jin, Jing; Hines, William A; Kuo, Chung-Hao; Perry, David M; Poyraz, Altug S; Xia, Yan; Zaidi, Taha; Nieh, Mu-Ping; Suib, Steven L

    2015-07-14

    A combined magnetization and (57)Fe spin-echo nuclear magnetic resonance (NMR) study has been carried out on mesoporous nanostructured materials consisting of the magnetite (Fe3O4) and maghemite (γ-Fe2O3) phases. Two series of samples were synthesized using a recently developed one-step soft-templating approach with systematic variations in calcination temperature and reaction atmosphere. Nuclear magnetic resonance has been shown to be a valuable tool for distinguishing between the two magnetic iron oxide spinel phases, Fe3O4 and γ-Fe2O3, on the nanoscale as well as monitoring phase transformation resulting from oxidation. For the Fe3O4 and γ-Fe2O3 phases, peaks in the NMR spectra are attributed to Fe in the tetrahedral (A) sites and octahedral (B) sites. The magnetic field dependence of the peaks was observed and confirmed the site assignments. Fe3O4 on a nanoscale readily oxidizes to form γ-Fe2O3 and this was clearly evident in the NMR spectra. As evidenced by transmission electron microscope (TEM) images, the porous mesostructure for the iron oxide materials is formed by a random close-packed aggregation of nanoparticles; correspondingly, superparamagnetic behavior was observed in the magnetic measurements. Although X-ray diffraction (XRD) shows the spinel structure for the Fe3O4 and γ-Fe2O3 phases, unlike NMR, it is difficult to distinguish between the two phases with XRD. Nitrogen sorption isotherms characterize the mesoporous structures of the materials, and yield BET surface area values and limited BJH pore size distribution curves. PMID:26067028

  20. Work function characterization of electroactive materials using an E MOSFET

    OpenAIRE

    Anh, Dam Thi Van; Olthuis, Wouter; Bergveld, Piet

    2004-01-01

    Materials with redox properties have been widely used in sensing applications. Understanding the redox properties of these materials is an important issue. In order to investigate the redox properties, there are several methods, such as using the Kelvin probe and a conductivity sensor, or using other well-known electrochemical techniques. In this paper, we introduce another possibility to characterize redox materials by investigating their work function using an electrolyte metal-oxide semico...

  1. Growth and Characterization of Skyrmion-hosting Magnetic Thin Films

    Science.gov (United States)

    Youngblood, Brian J.

    Magnetic skyrmions are particle-like knots of magnetization which are both highly stable under the proper conditions and at the same time very easy to move and rotate. These properties make them very promising as a basis for future spin electronic information storage and manipulation. At the same time, these structures exhibit interesting fundamental physics including emergent mass and electrodynamics and phase transitions including a crystalline state as well as being low-dimensional analogues of a model of low-energy sub-atomic particles. Accessibility to studying these objects is hampered by the fact that most skyrmion-hosting materials have to be grown either as single crystals or by molecular beam epitaxy (MBE). Also, predictive studies are currently mostly restricted to full numerical simulations because of the intractability of the equation describing skyrmion structure and a dearth of analytical approximations. In this dissertation, I present work on the sputter deposition of the skyrmion hosting chiral magnetic material MnSi. MnSi was the first material observed to exhibit a skyrmion state but it has not been made by sputtering until now. I demonstrate by x-ray diffractometry and electrical measurements that the sputter-deposited MnSi exhibits properties similar to those of MBE-grown thin films including hosting skyrmions. This will hopefully improve the accessibility of experimental studies of MnSi and skyrmions. I also present an approximation for skyrmion spatial profiles which can predict skyrmion structure in a physically interesting range of material parameters and external magnetic fields. Using this structural approximation it should be possible to predict skyrmion stability and behavior under different conditions more rapidly than is possible with numerical simulations.

  2. Characterization of magnetized ore bodies based on three-component borehole magnetic and directional borehole seismic measurements

    Science.gov (United States)

    Virgil, Christopher; Neuhaus, Martin; Hördt, Andreas; Giese, Rüdiger; Krüger, Kay; Jurczyk, Andreas; Juhlin, Christopher; Juhojuntti, Niklas

    2016-04-01

    In the last decades magnetic prospecting using total field data was used with great success for localization and characterization of ferromagnetic ore bodies. Especially borehole magnetic measurements reveal important constraints on the extent and depth of potential mining targets. However, due to the inherent ambiguity of the interpretation of magnetic data, the resulting models of the distribution of magnetized material, such as iron ore bodies, are not entirely reliable. Variations in derived parameters like volume and estimated ore content of the expected body have significant impact on the economic efficiency of a planned mine. An important improvement is the introduction of three-component borehole magnetic sondes. Modern tools comprise orientation modules which allow the continuous determination of the tool's heading regardless of the well inclination and independent of the magnetic field. Using the heading information the recorded three-component magnetic data can be transferred from the internal tool's frame to the geographic reference frame. The vector information yields a more detailed and reliable description of the ore bodies compared to total field or horizontal and vertical field data. Nevertheless complementary information to constrain the model is still advisable. The most important supplementary information for the interpretation of magnetic data is the knowledge of the structural environment of the target regions. By discriminating dissimilar rock units, a geometrical starting model can be derived, constraining the magnetic interpretation and leading to a more robust estimation of the rock magnetizations distribution. The most common approach to reveal the lithological setting rests upon seismic measurements. However, for deep drilling targets surface seismic and VSP lack the required spatial resolution of 10s of meters. A better resolution is achieved by using directed sources and receivers inside the borehole. Here we present the application of

  3. Predicting the Future of Permanent-Magnet Materials

    Energy Technology Data Exchange (ETDEWEB)

    Skomski, R; Manchanda, P; Kumar, P; Balamurugan, B; Kashyap, A; Sellmyer, DJ

    2013-07-01

    There are two main thrusts towards new permanent-magnet materials: improving extrinsic properties by nanostructuring and intrinsic properties by atomic structuring. Theory-both numerical and analytical-plays an important role in this ambitious research. Our analysis of aligned hard-soft nanostructures shows that soft-in-hard geometries are better than hard-in-soft geometries and that embedded soft spheres are better than sandwiched soft layers. Concerning the choice of the hard phase, both a high magnetization and a high anisotropy are necessary. As an example of first-principle research, we consider interatomic Mn exchange in MnAl and find strongly ferromagnetic intralayer exchange, in spite of the small Mn-Mn distances.

  4. Synthesis, characterization and magnetic properties of Fe3O4 doped chitosan polymer

    International Nuclear Information System (INIS)

    Fe3O4 nanoparticles doped into chitosan films were prepared by the solution casting technique. Various samples were synthesized in atmospheric medium and in vacuum. The morphological properties of the samples were characterized by high resolution transmission electron microscopy (HR-TEM) and Scanning Electron Microscopy (SEM). The structural, magnetic, and microwave absorption properties of magnetic chitosan films have been carried out using the Vibrating Sample Magnetometer (VSM) and Ferromagnetic Resonance (FMR). It is shown that the composite polymer behaves like a superparamagnetic material with high blocking temperature. The effective magnetization shows gradual increments with the concentration of dopant Fe3O4 nanoparticles. The microwave absorption characteristic of superparamagnetic composite polymer shows low reflection loss. - Highlights: • Chitosan polymers doped with Fe3O4 are prepared by the solution casting technique. • The structural, magnetic, and microwave absorption properties of the samples are analyzed. • The polymer behaves like a superparamagnetic material with high blocking temperature. • The effective magnetization shows gradual increments with the concentration of Fe3O4. • The microwave absorption characteristic shows low reflection loss

  5. Using Virtual Testing for Characterization of Composite Materials

    Science.gov (United States)

    Harrington, Joseph

    Composite materials are finally providing uses hitherto reserved for metals in structural systems applications -- airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. They have high strength-to-weight ratios, are durable and resistant to environmental effects, have high impact strength, and can be manufactured in a variety of shapes. Generalized constitutive models are being developed to accurately model composite systems so they can be used in implicit and explicit finite element analysis. These models require extensive characterization of the composite material as input. The particular constitutive model of interest for this research is a three-dimensional orthotropic elasto-plastic composite material model that requires a total of 12 experimental stress-strain curves, yield stresses, and Young's Modulus and Poisson's ratio in the material directions as input. Sometimes it is not possible to carry out reliable experimental tests needed to characterize the composite material. One solution is using virtual testing to fill the gaps in available experimental data. A Virtual Testing Software System (VTSS) has been developed to address the need for a less restrictive method to characterize a three-dimensional orthotropic composite material. The system takes in the material properties of the constituents and completes all 12 of the necessary characterization tests using finite element (FE) models. Verification and validation test cases demonstrate the capabilities of the VTSS.

  6. Magnetic properties of nanocrystalline cobalt based powder soft magnetic materials and nanocomposites with silicon matrix

    International Nuclear Information System (INIS)

    The paper presents the effect of the high energy ball milling parameters and of isothermal heating of the cobalt based metallic glasses on the magnetic properties and structure of the powder material and silicon matrix nano-composites. The high energy ball milling process of the Co68Fe4Mo1Si13.5B13.5 metallic glass was carried out for various time period in the 'as quenched' state and after the isothermal heating. Heating of powder obtained by milling was also performed, to check its effect on changes of magnetic properties. The effects of the high energy ball milling and isothermal heating on the structure, grain size and magnetic properties of powder, and of the silicon base nano-composites made from them were also investigated. (author)

  7. Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu Gaunkar, N., E-mail: neelampg@iastate.edu; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Bulu, I.; Ganesan, K.; Song, Y. Q. [Schlumberger-Doll Research, Cambridge, Massachusetts 02139 (United States)

    2015-05-07

    This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

  8. Pixel hybrid photon detector magnetic distortions characterization and compensation

    CERN Document Server

    Aglieri-Rinella, G; D'Ambrosio, Carmelo; Forty, Roger W; Gys, Thierry; Patel, Mitesh; Piedigrossi, Didier; Van Lysebetten, Ann

    2004-01-01

    The LHCb experiment requires positive kaon identification in the momentum range 2-100 GeV/c. This is provided by two ring imaging Cherenkov detectors. The stringent requirements on the photon detectors are fully satisfied by the novel pixel hybrid photon detector, HPD. The HPD is a vacuum tube with a quartz window, S20 photo-cathode, cross-focusing electron optics and a silicon anode encapsulated within the tube. The anode is a 32*256 pixels hybrid detector, with a silicon sensor bump-bonded onto a readout chip containing 8192 channels with analogue front-end and digital read-out circuitry. An external magnetic field influences the trajectory of the photoelectrons and could thereby degrade the inherent excellent space resolution of the HPD. The HPDs must be operational in the fringe magnetic field of the LHCb magnet. This paper reports on an extensive experimental characterization of the distortion effects. The characterization has allowed the development of parameterisations and of a compensation algorithm. ...

  9. Magnetism of uranium/iron multilayers: I. Fabrication and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Beesley, A M [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Thomas, M F [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Herring, A D F [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Ward, R C C [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Wells, M R [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Langridge, S [ISIS, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX (United Kingdom); Brown, S D [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Zochowski, S W [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Bouchenoire, L [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Stirling, W G [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lander, G H [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, Karlsruhe, D-76125 (Germany)

    2004-12-01

    U/Fe multilayers constitute a magnetic system in which the 3d magnetism of the Fe layers will be modified by hybridization with the U 5f electrons. This paper describes a programme of measurements of the magnetic behaviour of these systems beginning with the fabrication and thorough characterization of the samples. Metallic U/Fe multilayers were prepared by DC sputtering in a UHV chamber. A range of samples with measured U thicknesses, t{sub U}, in the range 18-66 A and Fe thicknesses, t{sub Fe}, from 7 to 108 A was fabricated. X-ray and neutron reflectivity measurements showed strong peaks indicating good layer structure and gave a determination of the bilayer thickness. X-ray diffraction analysis showed crystalline {alpha}-U and {alpha}-Fe for layer thicknesses greater than about 20 A. The {alpha}-Fe is strongly textured with (110) planes in the layer plane. The Fe lattice parameter is larger for the case of thin layers, but approaches the bulk value of 2.866 A at t{sub Fe} {approx} 75 A. Moessbauer spectra of {alpha}-Fe were obtained for t{sub Fe} {>=}18 A; a non-magnetic component of thickness {approx}12 A per layer is always present. The results from these different experimental techniques are combined to present a detailed description of these multilayer systems.

  10. Magnetic Properties of Ni-Fe Nanowire Arrays: Effect of Template Material and Deposition Conditions

    OpenAIRE

    Aravamudhan, Shyam; Singleton, John; Goddard, Paul A.; Bhansali, Shekhar

    2008-01-01

    The objective of this work is to study the magnetic properties of arrays of Ni-Fe nanowires electrodeposited in different template materials such as porous silicon, polycarbonate and alumina. Magnetic properties were studied as a function of template material, applied magnetic field (parallel and perpendicular) during deposition, wire length, as well as magnetic field orientation during measurement. The results show that application of magnetic field during deposition strongly influences the ...

  11. Manganese ferrite prepared using reverse micelle process: Structural and magnetic properties characterization

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Mohd, E-mail: md.hashim09@gmail.com [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Shirsath, Sagar E. [Spin Device Technology Centre, Department of Engineering, Shinshu University, Nagano 380-8553 (Japan); Meena, S.S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mane, M.L. [Department of Physics, S.G.R.G. Shinde Mahavidyalaya, Paranda 413502, MS (India); Kumar, Shalendra [School of Materials Science and Engineering, Changwon National University, Changwon, Gyeongnam 641-773 (Korea, Republic of); Bhatt, Pramod [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ravi [Centre for Material Science Engineering, National Institute of Technology, Hamirpur, HP (India); Prasad, N.K.; Alla, S.K. [Deptartment of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Shah, Jyoti; Kotnala, R.K. [National Physical Laboratory (CSIR), Dr. K.S. Krishnan Road, New Delhi 110012 (India); Mohammed, K.A. [Department of Mathematics & Physics Sciences, College of Arts and Sciences, University of Nizwa, Nizwa (Oman); Şentürk, Erdoğan [Department of Physics, Sakarya University, Esentepe, 54187 Sakarya (Turkey); Alimuddin [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

    2015-09-05

    Highlights: • Preparation of Mn{sup 3+} substituted MnFe{sub 2}O{sub 4} ferrite by Reverse microemulsion process. • Characterization by XRD, SEM, VSM, Mössbauer spectroscopy and dielectric measurements techniques. • Magnetic properties of MnFe{sub 2}O{sub 4} enhanced after Mn{sup 3+} substitution. • The dielectric constant and ac conductivity increased with Mn{sup 3+} substitution. - Abstract: Reverse microemulsion process was employed to prepare of nanocrystalline Mn{sup 3+} substituted MnFe{sub 2−x}Mn{sub x}O{sub 4} ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn{sup 3+}. The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn{sup 3+}. The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn{sup 3+} in MnFe{sub 2}O{sub 4} ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn{sup 3+} substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn{sup 3+} substitution was also analyzed. All the magnetic characterization shows that Mn{sup 3+} substitution enhance the magnetic behavior of MnFe{sub 2}O{sub 4} ferrite nanoparticles.

  12. Manganese ferrite prepared using reverse micelle process: Structural and magnetic properties characterization

    International Nuclear Information System (INIS)

    Highlights: • Preparation of Mn3+ substituted MnFe2O4 ferrite by Reverse microemulsion process. • Characterization by XRD, SEM, VSM, Mössbauer spectroscopy and dielectric measurements techniques. • Magnetic properties of MnFe2O4 enhanced after Mn3+ substitution. • The dielectric constant and ac conductivity increased with Mn3+ substitution. - Abstract: Reverse microemulsion process was employed to prepare of nanocrystalline Mn3+ substituted MnFe2−xMnxO4 ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn3+. The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn3+. The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn3+ in MnFe2O4 ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn3+ substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn3+ substitution was also analyzed. All the magnetic characterization shows that Mn3+ substitution enhance the magnetic behavior of MnFe2O4 ferrite nanoparticles

  13. Student understanding of electric and magnetic fields in materials

    CERN Document Server

    Mitchem, Savannah L; Sayre, Eleanor C

    2016-01-01

    We discuss the clusters of resources that emerge when upper-division students enrolled in an upper-division electricity and magnetism course write about fields in linear materials. We examine how these clusters change with time and context. The evidence shows that students benefit from activating resources related to the internal structure of the atom when thinking about electric fields and their effect on materials. We argue that facilitating activation of certain resources by the instructor in the classroom can affect the plasticity of those resources in the student, making them more solid and easily activated. We find that the wording of the questions posed to students affects which resources are activated, and that students often fill in resources to link known phenomena to phenomena described by the question when lacking detailed mental models.

  14. Optical Characterization of Window Materials for Aerospace Applications

    Science.gov (United States)

    Tedjojuwono, Ken K.; Clark, Natalie; Humphreys, William M., Jr.

    2013-01-01

    An optical metrology laboratory has been developed to characterize the optical properties of optical window materials to be used for aerospace applications. Several optical measurement systems have been selected and developed to measure spectral transmittance, haze, clarity, birefringence, striae, wavefront quality, and wedge. In addition to silica based glasses, several optical lightweight polymer materials and transparent ceramics have been investigated in the laboratory. The measurement systems and selected empirical results for non-silica materials are described. These measurements will be used to form the basis of acceptance criteria for selection of window materials for future aerospace vehicle and habitat designs.

  15. Magnetic microgels, a promising candidate for enhanced magnetic adsorbent particles in bioseparation: synthesis, physicochemical characterization, and separation performance.

    Science.gov (United States)

    Turcu, Rodica; Socoliuc, Vlad; Craciunescu, Izabell; Petran, Anca; Paulus, Anja; Franzreb, Matthias; Vasile, Eugeniu; Vekas, Ladislau

    2015-02-01

    For specific applications in the field of high gradient magnetic separation of biomaterials, magnetic nanoparticle clusters of controlled size and high magnetic moment in an external magnetic field are of particular interest. We report the synthesis and characterization of magnetic microgels designed for magnetic separation purposes, as well as the separation efficiency of the obtained microgel particles. High magnetization magnetic microgels with superparamagnetic behaviour were obtained in a two-step synthesis procedure by a miniemulsion technique using highly stable ferrofluid on a volatile nonpolar carrier. Spherical clusters of closely packed hydrophobic oleic acid-coated magnetite nanoparticles were coated with cross linked polymer shells of polyacrylic acid, poly-N-isopropylacrylamide, and poly-3-acrylamidopropyl trimethylammonium chloride. The morphology, size distribution, chemical surface composition, and magnetic properties of the magnetic microgels were determined using transmission electron microscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. Magnetically induced phase condensation in aqueous suspensions of magnetic microgels was investigated by optical microscopy and static light scattering. The condensed phase consists of elongated oblong structures oriented in the direction of the external magnetic field and may grow up to several microns in thickness and tens or even hundreds of microns in length. The dependence of phase condensation magnetic supersaturation on the magnetic field intensity was determined. The experiments using high gradient magnetic separation show high values of separation efficiency (99.9-99.97%) for the magnetic microgels. PMID:25519891

  16. Conceptual Design Report for the Irradiated Materials Characterization Laboratory (IMCL)

    Energy Technology Data Exchange (ETDEWEB)

    Stephanie Austad

    2010-06-01

    This document describes the design at a conceptual level for the Irradiated Materials Characterization Laboratory (IMCL) to be located at the Materials and Fuels Complex (MFC) at the Idaho National Laboratory (INL). The IMCL is an 11,000-ft2, Hazard Category-2 nuclear facility that is designed for use as a state of the-art nuclear facility for the purpose of hands-on and remote handling, characterization, and examination of irradiated and nonirradiated nuclear material samples. The IMCL will accommodate a series of future, modular, and reconfigurable instrument enclosures or caves. To provide a bounding design basis envelope for the facility-provided space and infrastructure, an instrument enclosure or cave configuration was developed and is described in some detail. However, the future instrument enclosures may be modular, integral with the instrument, or reconfigurable to enable various characterization environments to be configured as changes in demand occur. They are not provided as part of the facility.

  17. Eddy Current Pulsed Thermography with Different Excitation Configurations for Metallic Material and Defect Characterization

    Science.gov (United States)

    Tian, Gui Yun; Gao, Yunlai; Li, Kongjing; Wang, Yizhe; Gao, Bin; He, Yunze

    2016-01-01

    This paper reviews recent developments of eddy current pulsed thermography (ECPT) for material characterization and nondestructive evaluation (NDE). Due to the fact that line-coil-based ECPT, with the limitation of non-uniform heating and a restricted view, is not suitable for complex geometry structures evaluation, Helmholtz coils and ferrite-yoke-based excitation configurations of ECPT are proposed and compared. Simulations and experiments of new ECPT configurations considering the multi-physical-phenomenon of hysteresis losses, stray losses, and eddy current heating in conjunction with uniform induction magnetic field have been conducted and implemented for ferromagnetic and non-ferromagnetic materials. These configurations of ECPT for metallic material and defect characterization are discussed and compared with conventional line-coil configuration. The results indicate that the proposed ECPT excitation configurations can be applied for different shapes of samples such as turbine blade edges and rail tracks. PMID:27338389

  18. PtCo/Au nanocomposite: Synthesis, characterization, and magnetic properties

    Science.gov (United States)

    Dai, Jingtao; Du, Yukou; Wang, Fangwei; Yang, Ping

    2007-09-01

    Magnetic PtCo/Au nanocomposites with narrow size distribution were synthesized in a reverse micelle, followed by a post-synthesis handling of the stabilizer-exchange technique. The PtCo/Au nanocomposites were characterized by ultraviolet visible spectroscopy, X-ray diffraction and transmission electron microscopy, respectively. Superconducting quantum interference device studies revealed that the nanocomposites were superparamagnetic above the blocking temperature ( TB=69 K), while the samples were ferromagnetic with Hc (628 Oe) and Ms (2.97 emu /g) at 5 K.

  19. Characterization of human breast disease using phosphorus magnetic resonance spectroscopy and proton magnetic resonance imaging

    International Nuclear Information System (INIS)

    This thesis provides the fundamental characterization and differentiation of breast tissues using in vivo and ex vivo MR techniques in the hope that these techniques and experimental findings will be used on a larger scale and in a predictive manner in order to improve the specificity of diagnosis and treatment of breast cancer. In this dissertation, clinical studies were performed using proton magnetic resonance imaging and phosphorus magnetic resonance spectro-scopy (31P MRS) to characterize and differentiate malignant breast tumors, benign breast tumors and normal breast tissues in vivo. These studies were carried out following the methodical characterization of chemical extracts of malignant breast tumor, benign breast tumor and normal breast parenchymal surgical tissue specimens using high resolution 31P MRS. Alterations in breast tissue metabolism, as a result of pathological processes, were postulated to be responsible for measurable differences between malignant breast tumors, benign breast tumors and normal breast tissues using magnetic resonance techniques. (author). 365 refs.; 37 figs.; 25 tabs

  20. Polymeric variable optical attenuators based on magnetic sensitive stimuli materials

    International Nuclear Information System (INIS)

    Magnetically-actuable, polymer-based variable optical attenuators (VOA) are presented in this paper. The design comprises a cantilever which also plays the role of a waveguide and the input/output alignment elements for simple alignment, yet still rendering an efficient coupling. Magnetic properties have been conferred to these micro-opto-electromechanical systems (MOEMS) by implementing two different strategies: in the first case, a magnetic sensitive stimuli material (M-SSM) is obtained by a combination of polydimethylsiloxane (PDMS) and ferrofluid (FF) in ratios between 14.9 wt % and 29.9 wt %. An M-SSM strip under the waveguide-cantilever, defined with soft lithography (SLT), provides the required actuation capability. In the second case, specific volumes of FF are dispensed at the end of the cantilever tip (outside the waveguide) by means of inkjet printing (IJP), obtaining the required magnetic response while holding the optical transparency of the waveguide-cantilever. In the absence of a magnetic field, the waveguide-cantilever is aligned with the output fiber optics and thus the intrinsic optical losses can be obtained. Numerical simulations, validated experimentally, have shown that, for any cantilever length, the VOAs defined by IJP present lower intrinsic optical losses than their SLT counterparts. Under an applied magnetic field (Bapp), both VOA configurations experience a misalignment between the waveguide-cantilever and the output fiber optics. Thus, the proposed VOAs modulate the output power as a function of the cantilever displacement, which is proportional to Bapp. The experimental results for the three different waveguide-cantilever lengths and six different FF concentrations (three per technology) show maximum deflections of 220 µm at 29.9 wt % of FF for VOASLT and 250 µm at 22.3 wt % FF for VOAIJP, at 0.57 kG for both. These deflections provide maximum actuation losses of 16.1 dB and 18.9 dB for the VOASLT and VOAIJP

  1. Materials characterization in petroleum pipeline using Compton Scattering technique

    Science.gov (United States)

    Gouveia, M. A. G.; Lopes, R. T.; de Jesus, E. F. O.; Camerini, C. S.

    2003-06-01

    In this paper Compton Scattering technique is analyzed as a possible tool for the characterization of materials inside draining petroleum pipelines. The study was accomplished in laboratory scale, so the results should be analyzed to conclude if the system could be used in the field. The system used was composed of two detectors aligned by a Ce-137 source forming an angle of 90° with the detectors line (662 keV—direct beam, and 288 keV—scattered beam). The results obtained show the capability of the system for the characterization of materials like sand, paraffin and water inside pipelines.

  2. Mechanical and Thermal Characteristics of Insulation Materials for the KSTAR Magnet System at Cryogenic Temperature

    Science.gov (United States)

    Chung, Wooho; Lim, Bungsu; Kim, Myungkyu; Park, Hyunki; Kim, Keeman; Chu, Yong; Lee, Sangil

    2004-06-01

    The KSTAR(Korea Superconducting Tokamak Advanced Research) superconducting magnet is electrically insulated by the composite material of epoxy resin and glass fiber (2.5 kV/mm) and Kapton (8 kV/mm). The insulation composite material of epoxy resin and glass fiber is prepared using a VPI (Vacuum Pressure Impregnation) process. The superconducting magnet is under mechanical stress caused by the large temperature difference between the operation temperature of the magnet and room temperature. The large electro-magnetic force during the operation of the magnet is also exerted on the magnet. Therefore, the characteristics of the insulation material at cryogenic temperatures are very important and the tensile stress and thermal expansion coefficient for the insulation materials of the KSTAR superconducting magnet are measured. This paper presents results on mechanical properties of the insulation material for KSTAR magnets, such as density, ultimate tensile stress and thermal contraction between room temperature and cryogenic temperatures.

  3. Materials, Strands, and Cables for Superconducting Accelerator Magnets. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sumption, Mike D. [Ohio State University, Columbia, OH (United States); Collings, Edward W. [Ohio State University, Columbia, OH (United States)

    2014-09-19

    This report focuses on Materials, Strands and Cables for High Energy Physics Particle accelerators. In the materials area, work has included studies of basic reactions, diffusion, transformations, and phase assemblage of Nb3Sn. These materials science aspects have been married to results, in the form of flux pinning, Bc2, Birr, and transport Jc, with an emphasis on obtaining the needed Jc for HEP needs. Attention has also been paid to the “intermediate-temperature superconductor”, magnesium diboride emphasis being placed on (i) irreversibility field enhancement, (ii) critical current density and flux pinning, and (iii) connectivity. We also report on studies of Bi-2212. The second area of the program has been in the area of “Strands” in which, aside from the materials aspect of the conductor, its physical properties and their influence on performance have been studied. Much of this work has been in the area of magnetization estimation and flux jump calculation and control. One of the areas of this work was strand instabilities in high-performance Nb3Sn conductors due to combined fields and currents. Additionally, we investigated quench and thermal propagation in YBCO coated conductors at low temperatures and high fields. The last section, “Cables”, focussed on interstrand contact resistance, ICR, it origins, control, and implications. Following on from earlier work in NbTi, the present work in Nb3Sn has aimed to make ICR intermediate between the two extremes of too little contact (no current sharing) and too much (large and unacceptable magnetization and associated beam de-focussing). Interstrand contact and current sharing measurements are being made on YBCO based Roebel cables using transport current methods. Finally, quench was investigated for YBCO cables and the magnets wound from them, presently with a focus on 50 T solenoids for muon collider applications.

  4. Characterization of Thermal Interface Materials to Support Thermal Simulation

    OpenAIRE

    Schacht, R.; May, D.; Wunderle, B.; Wittler, O.; Gollhardt, A.; Michel, B; Reichl, H.

    2007-01-01

    In this paper new characterization equipment for thermal interface materials is presented. Thermal management of electronic products relies on the effec-tive dissipation of heat. This can be achieved by the optimization of the system design with the help of simulation methods. The precision of these models relies also on the used material data. For the determi-nation of this data an experimental set-up for a static measurement is presented, which evaluates thermal conductivity and interface r...

  5. Materials Growth and Characterization of Thermoelectric and Resistive Switching Devices

    OpenAIRE

    Norris, Kate Jeanne

    2015-01-01

    In the 74 years since diode rectifier based radar technology helped the allied forces win WWII, semiconductors have transformed the world we live in. From our smart phones to semiconductor-based energy conversion, semiconductors touch every aspect of our lives. With this thesis I hope to expand human knowledge of semiconductor thermoelectric devices and resistive switching devices through experimentation with materials growth and subsequent materials characterization. Metal organic chemica...

  6. Thermal characterization of radiation processed contact lens material

    International Nuclear Information System (INIS)

    Differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and thermogravimetry analysis (TGA) were used to characterize radiation processed contact lens gel material of 2-hydroxy ethyl methacrylate(HEMA). DSC revealed two types of water in the gels. DSC and TGA in combination were used to quantitate the percentage of different types of the water in the gel material. Temperature expansion coefficients values indicate more dimensions stability in the radiation processed lenses of similar water contents. (author)

  7. Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Tito

    2015-10-27

    A method of separating a liquid hydrocarbon material from a body of water, includes: (a) mixing magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the magnetic carbon-metal nanocomposites each to be adhered by the liquid hydrocarbon material to form a mixture; (b) applying a magnetic force to the mixture to attract the magnetic carbon-metal nanocomposites each adhered by the liquid hydrocarbon material; and (c) removing the body of water from the magnetic carbon-metal nanocomposites each adhered by the liquid hydrocarbon material while maintaining the applied magnetic force. The magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material, for a period of time effective to allow the carbon-metal nanocomposites to be formed.

  8. Fabrication, characterization, manipulation and application of magnetic nanostructures

    Science.gov (United States)

    Sun, Li

    Nanostructured materials have not only abundant new physics but also application importance. Nanosciences include developing new techniques and exploring new phenomena. This dissertation presents the fabrication and property investigation of magnetic nanowires and exchange coupled NiFe/CoO nanostructured networks. Functionalization and potential biomedical applications of multicomponent nanowires are discussed. Using nuclear track etching, nanopores with controlled areal density (1-1011/cm2) and size (diameter > 10nm) are fabricated in polycarbonate membranes and mica single crystal wafers. Pore morphology depends strongly on the etching properties of the matrix. In contrast to the cylindrical pores in polycarbonate, etched nanopores in single crystalline mica membranes maintain diamond shape cross-sections, as a replica of the oxygen terminated planes of the unit cell. Compared to conventional nanoporous polymer membraness, mica template provides better thermal stability, chemical stability, mechanical rigidity and atomically smooth surfaces. Different materials have been electrodeposited into the pores to form nanowires. Magnetic properties of the electrodeposited Ni nanowires exhibit strong size dependence. Coercivity and remnant magnetization increase with decreasing nanowire diameter. High temperature measurements on the Ni nanowires in mica show finite size effects in the quasi-one dimensional structures. Curie temperature shifts to lower temperature with decreasing wire diameter and follows the finite size scaling law. Due to the diamond shape wire cross-section, in-plane magnetic anisotropy based on two mutually perpendicular anisotropic axes has been observed. We also studied the magnetization reversal process when the external field rotated away from wire axis. In the 120nm Ni nanowires, transition from switching based on curling to coherent rotation has been observed when the angle between the field and wire axis is about 80°. Single nanowire

  9. Magnetic behavior of Joule-heated magnetic core-shell nanowires with positive magnetostrictive core material

    Science.gov (United States)

    Dumitru, Ioan; Astefanoaei, Iordana; Cimpoesu, Dorin; Stancu, Alexandru

    2015-10-01

    Temperature field is an important parameter to be known and controlled in the magnetization process of the core-shell nanowires. The paper analyzes the temperature dependence of hysteretic process in a core-shell nanowire subjected to a dc Joule heating process. An electrical current that passes through the wire induces a temperature and a thermal stress field in the system. Spatial and temporal evolution of the temperature in system was analyzed using a model based on time-dependent heat conduction equation. The stresses determined by thermal gradients and different expansion characteristics of core and shell materials were computed. The temperature and stress depend on the size parameters of the system, dc Joule current and the initial temperature of the system. The magnetic behavior of the nanowire was analyzed using the Micromag application. The magnetic state of the core is influenced by the temperature field induced by a dc current applied to the system. For core materials with positive magnetostriction coefficient the coercive field increases at the increase of dc current intensity passed through the system.

  10. Preparation of hard magnetic materials in thin film form

    Energy Technology Data Exchange (ETDEWEB)

    Pigazo, F.; Palomares, F.J. [Instituto de Ciencia de Materiales de Madrid-CSIC, c/ Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain); Cebollada, F. [EUITT-UPM, Carretera de Valencia km 7, 28031 Madrid (Spain); Gonzalez, J.M. [Unidad Asociada ICMM-IMA, c/ Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)], E-mail: jesus.m.gonzalez@icmm.csic.es

    2008-07-15

    We report on the preparation, by means of pulsed laser ablation deposition, of trilayers of nominal composition Cr/SmCo{sub 5}/Cr//Si with thicknesses in the order of 250/240/125 nm, respectively. According to the results of the structural, chemical and magnetic characterizations performed in our as-deposited samples, the Sm-Co layer was structurally amorphous, exhibited abrupt compositional interfaces with the capping and buffering layers, and coercivities of a few hundreds of Oe. Magnetic hardness was developed upon submitting the samples to current anneals under vacuum at temperatures in the range of 540-670 deg. C. The hardening process was followed in detail by correlating the phase distribution, the nature of the interlayer atomic diffusion processes, the occurrence of textures and the temperature dependence of the coercive force. From our results we conclude about (i) the occurrence of a large degree of Co diffusion/segregation, which results in the detection, from the diffraction and magnetometric results, of the presence of CoCr alloys in the treated samples, and (ii) the close correlation, evidenced from the fits of the temperature dependence of the coercive force to the micromagnetic model, between the coercivity optimization and the crystallinity enhancement of the SmCo{sub 5} grains.

  11. Laser-driven platform for generation and characterization of strong quasi-static magnetic fields

    CERN Document Server

    Santos, J J; Giuffrida, L; Forestier-Colleoni, P; Fujioka, S; Zhang, Z; Korneev, Ph; Bouillaud, R; Dorard, S; Batani, D; Chevrot, M; Cross, J; Crowston, R; Dubois, J -L; Gazave, J; Gregori, G; d'Humières, E; Hulin, S; Ishihara, K; Kojima, S; Loyez, E; Marquès, J -R; Morace, A; Nicolaï, Ph; Peyrusse, O; Poyé, A; Raffestin, D; Ribolzi, J; Roth, M; Schaumann, G; Serres, F; Tikhonchuk, V T; Vacar, Ph; Woolsey, N

    2015-01-01

    Quasi-static magnetic-fields up to $800\\,$T are generated in the interaction of intense laser pulses (500J, 1ns, 10^{17}W/cm^2) with capacitor-coil targets of different materials. The reproducible magnetic-field was consistently measured by three independent diagnostics: GHz-bandwidth inductor pickup coils (B-dot probes), Faraday rotation of polarized optical laser light and proton beam-deflectometry. The field rise time is consistent with the laser pulse duration, and it has a dipole-like distribution over a characteristic volume of 1mm^3, which is coherent with theoretical expectations. These results demonstrate a very efficient conversion of the laser energy into magnetic fields, thus establishing a robust laser-driven platform for reproducible, well characterized, generation of quasi-static magnetic fields at the kT-level, as well as for magnetization and accurate probing of high-energy-density samples driven by secondary powerful laser or particle beams.

  12. Synthesis and characterization of montmorillonite clay intercalated with molecular magnetic compounds

    Science.gov (United States)

    Martins, Marcel G.; Martins, Daniel O. T. A.; de Carvalho, Beatriz L. C.; Mercante, Luiza A.; Soriano, Stéphane; Andruh, Marius; Vieira, Méri D.; Vaz, Maria G. F.

    2015-08-01

    In this work montmorillonite (MMT) clay, whose matrix was modified with an ammonium salt (hexadecyltrimethylammonium bromide - CTAB), was employed as an inorganic host for the intercalation of three different molecular magnetic compounds through ion exchange: a nitronyl nitroxide derivative 2-[4-(N-ethyl)-pyridinium]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (p-EtRad+) and two binuclear coordination compounds, [Ni(valpn)Ln]3+, where H2valpn stands for 1,3-propanediyl-bis(2-iminomethylene-6-methoxy-phenol), and Ln=GdIII; DyIII. The pristine MMT and the intercalated materials were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and magnetic measurements. The X-ray diffraction data analysis showed an increase of the interlamellar space of the intercalated MMT, indicating the intercalation of the magnetic compounds. Furthermore, the magnetic properties of the hybrid compounds were investigated, showing similar behavior as the pure magnetic guest species.

  13. Microelectronics materials characterization studies at the Cornell TRIGA Reactor

    International Nuclear Information System (INIS)

    The Cornell program of microelectronics materials characterization by neutron activation analysis (NAA) is described. Experimental details and results from the successful application of NAA to silicon germanium circuit structures and nickel silicide layers are presented. In doing so, the potential for using X rays from isotopes that decay by electron capture is demonstrated. (author)

  14. Materials thermal and thermoradiative properties/characterization technology

    Science.gov (United States)

    Dewitt, D. P.; Ho, C. Y.

    1989-01-01

    Reliable properties data on well characterized materials are necessary for design of experiments and interpretation of experimental results. The activities of CINDAS to provide data bases and predict properties are discussed. An understanding of emissivity behavior is important in order to select appropriate methods for non-contact temperature determination. Related technical issues are identified and recommendations are offered.

  15. Electric characterization of construction materials through radar data inversion

    NARCIS (Netherlands)

    Patriarca, C.

    2013-01-01

    The non-destructive evaluation with the aim of characterizing objects before or after treatment has taken place, and the monitoring of long-term performance is analyzed in this thesis. Generally, these test methods measure material properties or changes in these properties that decision makers are i

  16. Artifacts by dental materials on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Hyun Sook; Choi, Deuk Lin; Kim, Ki Jung [Soonchunhyang University Hospital, Asan (Korea, Republic of); Suh, Won Hyuck [Korea University Hospital, Seoul (Korea, Republic of)

    1992-05-15

    Magnetic resonance imaging (MRI) has proved to be a valuable method for evaluation of the head and neck. Unfortunately, metallic devices associated with certain dental fillings and appliances often cause variable artifacts that can obscure normal or pathologic conditions on MR and computed tomography. In this work, we assessed the MR appearance of dental prosthetic materials in vitro and in vivo including precious alloys, nonprecions alloys, resin, amalgam and titanium alloy. For in vivo studies, these materials were placed in healthy volunteer's mouths and then images were assessed. Analysis of the appearance of shape and extent of artifact, and observed influence of these artifacts on the image interpretation at 0.2 Tesla permanent type MR scanner were valuated. Material used as temporary or permanent filling of crowns such as amalgam, precious alloy and, microfilled resin did not cause artifact on the image. The size of the artifact produced by the nonprecious alloys was influenced by the ferromagnetism of the object and the volume prosthesis, and was related to the scanning sequence. Nonprecious alloys produced minimal local signal distortion, where precious alloys, and dental resin had no effect on the MR images in vivo. These results were mainly from a low field strength MR scanner used in this study.

  17. Artifacts by dental materials on magnetic resonance imaging

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) has proved to be a valuable method for evaluation of the head and neck. Unfortunately, metallic devices associated with certain dental fillings and appliances often cause variable artifacts that can obscure normal or pathologic conditions on MR and computed tomography. In this work, we assessed the MR appearance of dental prosthetic materials in vitro and in vivo including precious alloys, nonprecions alloys, resin, amalgam and titanium alloy. For in vivo studies, these materials were placed in healthy volunteer's mouths and then images were assessed. Analysis of the appearance of shape and extent of artifact, and observed influence of these artifacts on the image interpretation at 0.2 Tesla permanent type MR scanner were valuated. Material used as temporary or permanent filling of crowns such as amalgam, precious alloy and, microfilled resin did not cause artifact on the image. The size of the artifact produced by the nonprecious alloys was influenced by the ferromagnetism of the object and the volume prosthesis, and was related to the scanning sequence. Nonprecious alloys produced minimal local signal distortion, where precious alloys, and dental resin had no effect on the MR images in vivo. These results were mainly from a low field strength MR scanner used in this study

  18. Nondestructive characterization of materials A growing demand for describing damage and service-life-relevant aging processes in plant components

    International Nuclear Information System (INIS)

    The nondestructive detection and characterization of damage to materials poses a challenge to instrumentation and inspection technology. A reliable method has yet to be developed anywhere in the world which is sufficiently rugged to be used on components in an industrial environment. The application-oriented studies conducted to date have demonstrated the complex overlapping of influences exerted on nondestructive measurement variables by the damage to be detected and by other material states and properties. The nondestructive detection and characterization of material damage will not offer any realistic chance of success until the material and component state is adequately characterized prior to the occurrence of the damage and variables are used which provide various types of information on the states and properties resulting from various interactions with the material. The process approaches and measurement techniques developed by the Institute for Nondestructive Testing are presented and evaluated below. The characterization of the initial state of a component with respect to its homogeneity and isotropy of its properties is possible by way of ultrasonic and magnetic techniques. Both techniques are also successfully employed in characterizing surface and bulk stress states in components. Adaptation of the sensor systems and material-specific preliminary testing are possibly required prior to actual application under practical conditions in individual cases. The same applies to the analysis of the anisotropy of material properties. Detecting areas of plastic deformation is possible via ultrasonic and magnetic techniques: quantification requires calibration, e.g. via a tensile test. (orig.)

  19. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leary, AM; Ohodnicki, PR; McHenry, ME

    2012-07-04

    Advanced soft magnetic materials are needed to match high-power density and switching frequencies made possible by advances in wide band-gap semiconductors. Magnetics capable of operating at higher operating frequencies have the potential to greatly reduce the size of megawatt level power electronics. In this article, we examine the role of soft magnetic materials in high-frequency power applications and we discuss current material's limitations and highlight emerging trends in soft magnetic material design for high-frequency and power applications using the materials paradigm of synthesis -> structure -> property -> performance relationships.

  20. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    Science.gov (United States)

    Leary, Alex M.; Ohodnicki, Paul R.; McHenry, Michael E.

    2012-07-01

    Advanced soft magnetic materials are needed to match high-power density and switching frequencies made possible by advances in wide band-gap semiconductors. Magnetics capable of operating at higher operating frequencies have the potential to greatly reduce the size of megawatt level power electronics. In this article, we examine the role of soft magnetic materials in high-frequency power applications and we discuss current material's limitations and highlight emerging trends in soft magnetic material design for high-frequency and power applications using the materials paradigm of synthesis → structure → property → performance relationships.

  1. The technique of Raman spectroscopy in the characterization physical, chemical and structural ferroelectric of the materials

    International Nuclear Information System (INIS)

    The ferroelectric ceramics have been one of the most studied compounds in the literature both in obtaining the same growth as in behavior of chemical and physical properties. In its growth the materials can go through other phases or to change their magnetic ferroelectric properties due to vacancies generated as PbTiO3 material. This material structural changes its phase also applying pressure with temperature, concentration and allowing anharmonic study behavior [1]. Raman spectroscopy is a technique which provides high resolution in seconds chemical and structural information of almost any organic or inorganic compound. As a technique which does not require a special atmosphere or vacuum, is one technique that has been used extensively in the characterization of ferroelectric materials in particular of PbTiO3

  2. Novel microwave near-field sensors for material characterization, biology, and nanotechnology

    Science.gov (United States)

    Joffe, R.; Kamenetskii, E. O.; Shavit, R.

    2013-02-01

    The wide range of interesting electromagnetic behavior of contemporary materials requires that experimentalists working in this field master many diverse measurement techniques and have a broad understanding of condensed matter physics and biophysics. Measurement of the electromagnetic response of materials at microwave frequencies is important for both fundamental and practical reasons. In this paper, we propose a novel near-field microwave sensor with application to material characterization, biology, and nanotechnology. The sensor is based on a subwavelength ferrite-disk resonator with magnetic-dipolar-mode (MDM) oscillations. Strong energy concentration and unique topological structures of the near fields originated from the MDM resonators allow effective measuring material parameters in microwaves, both for ordinary structures and objects with chiral properties.

  3. Novel microwave near-field sensors for material characterization, biology, and nanotechnology

    CERN Document Server

    Joffe, R; Shavit, R

    2015-01-01

    The wide range of interesting electromagnetic behavior of contemporary materials requires that experimentalists working in this field master many diverse measurement techniques and have a broad understanding of condensed matter physics and biophysics. Measurement of the electromagnetic response of materials at microwave frequencies is important for both fundamental and practical reasons. In this paper, we propose a novel near-field microwave sensor with application to material characterization, biology, and nanotechnology. The sensor is based on a subwavelength ferrite-disk resonator with magnetic-dipolar-mode (MDM) oscillations. Strong energy concentration and unique topological structures of the near fields originated from the MDM resonators allow effective measuring material parameters in microwaves, both for ordinary structures and objects with chiral properties.

  4. Composite Materials with Magnetically Aligned Carbon Nanoparticles Having Enhanced Electrical Properties and Methods of Preparation

    Science.gov (United States)

    Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

    2016-01-01

    Magnetically aligned carbon nanoparticle composites have enhanced electrical properties. The composites comprise carbon nanoparticles, a host material, magnetically sensitive nanoparticles and a surfactant. In addition to enhanced electrical properties, the composites can have enhanced mechanical and thermal properties.

  5. Fatigue effects in insulation materials for fusion magnets

    International Nuclear Information System (INIS)

    The mechanical properties of insulation materials for the superconducting magnets of ITER (International Thermonuclear Experimental Reactor) and future fusion plants, i.e. woven fiber reinforced composites, have been identified as an area of concern for the long-term operation of such magnets. The magnets will be subjected to fast neutron and γ-radiation over their lifetime, which influence the mechanical properties of the insulation materials. The ultimate tensile strength and, above all, the interlaminar shear strength and their performance under dynamic load, corresponding to the pulsed operation of a TOKAMAK-confinement system, are sensitive indicators of material failure in fiber-reinforced laminates especially at cryogenic temperatures. To simulate these conditions, low frequency fatigue measurements at 10 Hz were made at 77 K up to one million cycles. Tension-tension fatigue tests were performed according to ASTM D3479. However, due to the space limitations in all irradiation facilities, the tests have to be done on samples, which are considerably smaller than those required for standard test conditions. The influence of the specimen geometry on the ultimate tensile strength under static and dynamic load conditions was, therefore, investigated on fiber-reinforced plastics. They did not show any systematic trends as long as the sample thickness does not exceed the thickness recommended in ASTM D3479. The double lap shear test method was chosen for the shear experiments because of the symmetry of the specimen geometry under tensile load and the suitability for fatigue tests. Like almost every existing test procedure for the interlaminar shear strength, this test method does not provide for a completely uniform interlaminar shear stress distribution over a sizable region in the test section of the specimen. A scaling program combined with FE-simulations was, therefore, initiated to assess the influence of the length of the test section and of the sample

  6. EPR and magnetism of the nanostructured natural carbonaceous material shungite

    Science.gov (United States)

    Augustyniak-Jabłokow, Maria Aldona; Yablokov, Yurii V.; Andrzejewski, Bartłomiej; Kempiński, Wojciech; Łoś, Szymon; Tadyszak, Krzysztof; Yablokov, Mikhail Y.; Zhikharev, Valentin A.

    2010-04-01

    The X-band EPR and magnetic susceptibility in the temperature range 4.2-300 K study of the shungite-I, natural nanostructured material from the deposit of Shunga are reported. Obtained results allow us to assign the EPR signal to conduction electrons, estimate their number, N P, and evaluate the Pauli paramagnetism contribution to shungite susceptibility. A small occupation (~5%) of the localized nonbonding π states in the zigzag edges of the open-ended graphene-like layers and/or on σ ( sp 2+ x ) orbitals in the curved parts of the shungite globules has been also revealed. The observed temperature dependence of the EPR linewidth can be explained by the earlier considered interaction of conduction π electrons with local phonon modes associated with the vibration of peripheral carbon atoms of the open zigzag-type edges and with peripheral carbon atoms cross-linking different nanostructures. The relaxation time T 2 and diffusion time T D are found to have comparable values (2.84 × 10-8 and 1.73 × 10-8 s at 5.2 K, respectively), and similar dependence on temperature. The magnetic measurements have revealed the suppression of orbital diamagnetism due to small amount of large enough fragments of the graphene layers.

  7. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    KAUST Repository

    Oommen, Joanna Mary

    2010-08-13

    Nanoscale ionic materials (NIMs) are a new class of nanomaterials that exhibit interesting properties including negligible vapor pressures and tunable physical states, among others. In this study, we analyzed the temperature-wise performance of NIMs using nuclear magnetic resonance (NMR) spectroscopy. NIMs are relatively stable over a temperature range from 300 to 383 K, rendering them usable in high temperature applications. We confirmed the presence of covalent bonds between the SiO2 core and the sulfonate group and determined relative concentrations of aromatic and aliphatic hydrocarbons. These findings serve as first hand proof-of-concept for the usefulness of NMR analyses in further studies on the diffusive properties of NIMs. © 2010 The Electrochemical Society.

  8. Characterization of Three-Dimensional Magnetic Alignment for Magnetically Biaxial Particles

    Science.gov (United States)

    Yamaguchi, Masuhiro; Ozawa, Shun; Yamamoto, Isao; Kimura, Tsunehisa

    2013-01-01

    The three-dimensional magnetic alignment (3DMA) is analytically investigated for magnetically biaxial particles with the susceptibility χ1>χ2>χ3 in an amplitude-modulated (AM) elliptic field B= i1Bb1cos ωt + i2Bb2sin ωt as a prototype method for 3DMA. The distribution function and the biaxial ordering matrix are numerically calculated by the Boltzmann distribution and the rotational diffusion equation. The 3DMA attains the optimum performance in the rapid rotation regime (RRR) with the infinity rotation frequency ω while the RRR is effectively available at lower rotation frequencies. The intermediate magnetization axis χ2 is inferior to the easy and hard magnetization axes χ1 and χ3 in the time development and the equilibrium state of alignment. In all the methods for 3DMA, the dynamic and equilibrium behavior in the RRR are universally characterized by the reduced energy α= V(Bb1)2(χ3 - χ1)/(2µ0kBT), the biaxial deviation of susceptibility k = (χ2-χ1)/(χ3-χ1), the field modulation factor q = (b2/b1)2, and the reduced time tr = | α| Dt where D is the rotational diffusion constant.

  9. Raman characterization of high temperature materials using an imaging detector

    International Nuclear Information System (INIS)

    The characterization of materials by Raman spectroscopy has been advanced by recent technological developments in light detectors. Imaging photomultiplier-tube detectors are now available that impart position information in two dimensions while retaining photon-counting sensitivity, effectively greatly reducing noise. The combination of sensitivity and reduced noise allows smaller amounts of material to be analyzed. The ability to observe small amount of material when coupled with position information makes possible Raman characterization in which many spatial elements are analyzed simultaneously. Raman spectroscopy making use of these capabilities has been used, for instance, to analyze the phases present in carbon films and fibers and to map phase-transformed zones accompanying crack propagation in toughened zirconia ceramics. 16 refs., 6 figs., 2 tabs

  10. Raman characterization of high temperature materials using an imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Rosenblatt, G.M.; Veirs, D.K.

    1989-03-01

    The characterization of materials by Raman spectroscopy has been advanced by recent technological developments in light detectors. Imaging photomultiplier-tube detectors are now available that impart position information in two dimensions while retaining photon-counting sensitivity, effectively greatly reducing noise. The combination of sensitivity and reduced noise allows smaller amounts of material to be analyzed. The ability to observe small amount of material when coupled with position information makes possible Raman characterization in which many spatial elements are analyzed simultaneously. Raman spectroscopy making use of these capabilities has been used, for instance, to analyze the phases present in carbon films and fibers and to map phase-transformed zones accompanying crack propagation in toughened zirconia ceramics. 16 refs., 6 figs., 2 tabs.

  11. Characterization of semiconductor and frontier materials by nuclear microprobe technology

    International Nuclear Information System (INIS)

    The nuclear microprobe technology is used to characterize the properties of semiconductor and other frontier materials at the stages of their synthesis, modification, integration and application. On the basis of the beam current being used, the analytical nuclear microprobe techniques being used in this project can be divided into two categories: high beam current (PIXE, RBS, PEB) or low beam current (IBIC, STIM) techniques. The material properties measured are the thickness and composition of a composite surface on a SiC ceramic, the sputtering-induced surface segregation and depth profile change in a Ag-Cu binary alloy, the irradiation effects on the CCE of CVD diamond, the CCE profile at a polycrystalline CVD diamond film and a GaAs diode at different voltage biases and finally, the characterization of individual sample on an integrated material chip. (author)

  12. Magnetic refrigeration cycle analysis using selected thermodynamic property characterizations for gadolinium gallium garnet

    International Nuclear Information System (INIS)

    Magneto-thermodynamic property characterizations were selected, adapted, and compared to material property data for gadolinium gallium garnet in the temperature range 4--40 K and magnetic field range 0--6 T. The most appropriate formulations were incorporated into a model in which methods similar to those previously developed for other materials and temperature ranges were used to make limitation and relative performance assessments of Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. Analysis showed that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as those for materials previously examined, substantial improvements in cooling capacity/temperature lift combinations can be achieved using regenerative cycles within specified fields limits if significant loss mechanisms are mitigated

  13. Preparation and characterization of the fish reference material

    International Nuclear Information System (INIS)

    The certified reference materials (CRMs) play an important role in obtaining measurement results traceable to the International System of Units, through an unbroken chain of comparisons. Thus, the demand for new certified reference materials (CRMs) increases every day in all areas of knowledge. The availability of reference materials, mainly in Brazil is still incipient, given that the demand far exceeds the available variety of these materials. The amount of certified reference materials available in the country is insufficient to meet the need of the scientific community and demands for development of new methodologies. Among the many areas in need of reference materials, we highlight the importance for the food trade balance for these products within the country. The certification of food products, intended both for export and for domestic consumption, requires analysis methods that provide precise and accurate results to ensure product quality. This paper describes the preparation and certification of a reference material in the fish matrix in mercury and methylmercury. The study brings together since the stage of material selection, preparation, development of homogeneity and stability studies and characterization. The certification was performed by means of measurements using two analytical techniques, flow injection analysis - cold vapor atomic absorption spectrometry (FIA-CV-AAS) and isotope dilution applied to mass spectrometry (IDMS), which is a primary method. In this work the standards of the ISO 30 (ABNT 30-34) and ISO Guide 35 was used as the basis for the preparation and characterization of the material. For the calculation of uncertainties was used the GUM and Eurachem guide. As a result, was produced and certified a lot of material in relation to the concentration of mercury (Hg = 0.271 ± 0.057 mg g-1) and methylmercury (MeHg = 0.245 ± 0.038 mg g-1), and informational values of lead and arsenic. (author)

  14. Recent developments of rare-earth-free hard-magnetic materials

    Science.gov (United States)

    Li, Da; Pan, DeSheng; Li, ShaoJie; Zhang, ZhiDong

    2016-01-01

    Recent advances in rare-earth-free hard-magnetic materials including magnetic bulk, thin films, nanocomposites and nanostructures are introduced. Since the costs of the rare-earth metals boosts up the price of the high-performance rare-earth permanent magnets, there is a much revived interest in various types of hard-magnetic materials based on rare-earth-free compounds. The 3d transition metals and their alloys with large coercivity and high Curie temperatures (working temperatures) are expected to overcome the disadvantages of rare-earth magnets. Making rare-earth-free magnets with a large energy product to meet tomorrow's energy needs is still a challenge.

  15. Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material

    Energy Technology Data Exchange (ETDEWEB)

    Marins, Jéssica A., E-mail: Jessica.amarins@gmail.com [Universidade Federal do Rio de Janeiro/ Instituto de Macromoléculas, Centro de Tecnologia, Rio de Janeiro, RJ (Brazil); Soares, Bluma G., E-mail: bluma@ima.ufrj.br [Universidade Federal do Rio de Janeiro/ Instituto de Macromoléculas, Centro de Tecnologia, Rio de Janeiro, RJ (Brazil); Barud, Hernane S.; Ribeiro, Sidney J.L. [Universidade Estadual Paulista, Instituto de Química, UNESP, Araraquara, SP (Brazil)

    2013-10-15

    Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe{sub 3}O{sub 4} nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g{sup −1} and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. - Highlights: • Bacterial cellulose/magnetite nanocomposites with high incorporation degree of nanoparticles. • Magnetite nanoparticles well adhered to the surface of bacterial cellulose nanofibers. • A saturation magnetization of the nanoparticles in the BC pellicles of about 60 emu g{sup −1}. • Flexible membranes with high super-paramagnetic characteristic.

  16. Synthesis, characterization and magnetic properties of carbon nanotubes decorated with magnetic M{sup II}Fe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Syed Danish [National Centre for Physics, Quaid-e-Azam University Campus, Islamabad (Pakistan); Department of Chemistry, University of Engineering and Technology, Lahore (Pakistan); Hussain, Syed Tajammul, E-mail: dr_tajammul@yahoo.ca [National Centre for Physics, Quaid-e-Azam University Campus, Islamabad (Pakistan); Gilani, Syeda Rubina [Department of Chemistry, University of Engineering and Technology, Lahore (Pakistan)

    2013-04-15

    In this study, a simple, efficient and reproducible microemulsion method was applied for the successful decoration of carbon nanotubes (CNTs) with magnetic M{sup II}Fe{sub 2}O{sub 4} (M = Co, Ni, Cu, Zn) nanoparticles. The structure, composition and morphology of the prepared nanocomposite materials were characterized using X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The magnetic properties were investigated by the vibrating sample magnetometer (VSM). The SEM results illustrated that large quantity of M{sup II}Fe{sub 2}O{sub 4} nanoparticles were uniformly decorated around the circumference of CNTs and the sizes of the nanoparticles ranged from 15 to 20 nm. Magnetic hysteresis loop measurements revealed that all the M{sup II}Fe{sub 2}O{sub 4}/CNTs nanocomposites displayed ferromagnetic behavior at 300 K and can be manipulated using an external magnetic field. The CoFe{sub 2}O{sub 4}/CNTs nanocomposite showed maximum value of saturation magnetization which was 37.47 emu g{sup −1}. The as prepared M{sup II}Fe{sub 2}O{sub 4}/CNTs nanocomposites have many potential application in magnetically guided targeted drug delivery, clinical diagnosis, electrochemical biosensing, magnetic data storage and magnetic resonance imaging.

  17. Preparation and characterization of hybrid materials from natural chrysotile

    International Nuclear Information System (INIS)

    Special attention has been given to the development of new materials from natural chrysotile. This fiber has about 40% silicon oxide in its structure with an outer layer of brucite (MgOH2). With the aim of obtaining a material with a more uniform structure, acid leaching was performed to remove the outer layer of brucite, resulting in a silicon oxide hydrate. This material was used as support for the deposition of Nb2O5.nH2O. The Nb2O5.nH2O was prepared by conventional precipitation using as starting material niobium metallic. In this study, we performed the synthesis and characterization of the material SiO2.nH2O / Nb2O5.nH2O 1:1. Both chrysotile as niobium are widely available national resources, which confirms the economic viability of resource use. The materials studied were characterized by XRD, SEM and TG/DTG. (author)

  18. Characterization of the electromechanical properties of EAP materials

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrita, Stewart; Bhattachary, Kaushik; Lih, Shyh-Shiuh

    2001-01-01

    Electroactive polymers (EAP) are an emerging class of actuation materials. Their large electrically induced strains (longitudinal or bending), low density, mechanical flexibility, and ease of processing offer advantages over traditional electroactive materials. However, before the capability of these materials can be exploited, their electrical and mechanical behavior must be properly quantified. Two general types of EAP can be identified. The first type is ionic EAP, which requires relatively low voltages (materials requires large electric fields (>100MV/m) to achieve longitudinal deformations at the range from 4 - 360%. Some of the difficulties in characterizing EAP include: nonlinear properties, large compliance (large mismatch with metal electrodes), nonhomogeneity resulting from processing, etc. To support the need for reliable data, the authors are developing characterization techniques to quantify the electroactive responses and material properties of EAP materials. The emphasis of the current study is on addressing electromechanical issues related to the ion-exchange type EAP also known as IPMC. The analysis, experiments and test results are discussed in this paper.

  19. Layered material characterization using ultrasonic transmission. An inverse estimation methodology.

    Science.gov (United States)

    Messineo, María G; Rus, Guillermo; Eliçabe, Guillermo E; Frontini, Gloria L

    2016-02-01

    This paper presents an inverse methodology with the aim to characterize a layered material through the identification of acoustical and mechanical properties of its layers. The framework to accomplish this objective is provided by the Inverse Problems (IPs) theory. Material characterization refers to the detection and localization of discontinuities, as well as to the identification of physical properties, in order to predict the material behaviour. In this particular case, the IP is solved in the form of a parameter estimation problem, in which the goal is the estimation of the characteristic acoustic impedance, transit time, and attenuation of each layer. These parameters are directly related to relevant material properties, such as the speed of sound, density, elastic modulus and elastic energy dissipation constants. The IP solution is obtained by minimizing a cost functional formulated as the least squares error between the waveform calculated using an equivalent model, and the measured waveform obtained from ultrasonic transmission tests. The applied methodology allowed the accurate estimation of the desired parameters in materials composed of up to three layers. As a second contribution, a power law frequency dependence of the wave attenuation was identified for several homogeneous materials, based on the same ultrasonic transmission experiments. PMID:26456278

  20. Plutonium Immobilization Material Characterization: Milestone 1 Report - Initiate Design of Prototype Material Characterization System

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C.J.

    1999-06-01

    The objective of this task is to analyze impure oxide materials exiting from front-end processing prior to storage for feed blending. There are three goals to be accomplished with this task: reduce reblending (currently projected at 7% with an optimized ordering of the incoming material streams), determine if impure feed prep operations are performing adequately, and reduce plant operating costs by replacing wet prep elemental analyses whether conducted in the immobilization facility or in existing laboratories. An additional potential application is the analysis of blended oxide prior to first-stage UO{sub 2} and precursor addition.

  1. Three-dimensional nuclear magnetic resonance and x-ray microtomographic imaging of composite materials

    International Nuclear Information System (INIS)

    This paper presents a new, three-dimensional (3-D) nuclear magnetic resonance (NMR) imaging technique for spatially mapping proton distributions in green-state ceramic composites. The technique is based on a 3-D back-projection protocol for data acquisition, and a reconstruction technique based on 3-D Radon transform inversion. In principle, the 3-D methodology provides higher spatial resolution of solid materials than is possible with conventional slice-selection protocols. The applicability of 3-D NMR imaging has been demonstrated by mapping the organic additive distribution (2.5 wt. %) in cold-pressed Si3N4 whisker-reinforced Si3N4 ceramic composites. Three-dimensional X-ray computed tomography (CT) also has been employed for mapping voids and inclusions within the composite specimen. Combining information from both imaging modalities provides an extremely powerful nondestructive evaluation tool for materials characterization

  2. Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Gash, A; Pantoya, M; Jr., J S; Zhao, L; Shea, K; Simpson, R; Clapsaddle, B

    2003-11-18

    In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed.

  3. Magnetic characterization of multifilamentary BSCCO (2223) - Ag tapes

    International Nuclear Information System (INIS)

    Twisted and not twisted multifilamentary BSCCO (2223) - Ag tapes, prepared by the PIT technique, have been characterized by SQUID magnetometry with the magnetic field applied both parallel and perpendicular to the c-axis. From these measurements and estimation of the critical current densities Jab with Hext parallel to the c-axis Jab planes and Jc is obtained. These values are in fairly good agreement with those obtained by transport measurements. The tapes turned out to be very homogeneous and practically no difference was found in the hysteresis loops of twisted and not twisted tapes, which suggests that the mean grain alignment is the same in the two types of samples and the current path probably follows the 'brick wall' model

  4. In-situ materials characterization across spatial and temporal scales

    CERN Document Server

    Graafsma, Heinz; Zhang, Xiao; Frenken, Joost

    2014-01-01

    The behavior of nanoscale materials can change rapidly with time either because the environment changes rapidly, or because the influence of the environment propagates quickly across the intrinsically small dimensions of nanoscale materials. Extremely fast time resolution studies using X-rays, electrons and neutrons are of very high interest to many researchers and is a fast-evolving and interesting field for the study of dynamic processes. Therefore, in situ structural characterization and measurements of structure-property relationships covering several decades of length and time scales (from atoms to millimeters and femtoseconds to hours) with high spatial and temporal resolutions are crucially important to understand the synthesis and behavior of multidimensional materials. The techniques described in this book will permit access to the real-time dynamics of materials, surface processes, and chemical and biological reactions at various time scales. This book provides an interdisciplinary reference for res...

  5. Structural and magnetic characterization of electrodeposited Ni/Cu multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S.K., E-mail: sghosh@barc.gov.in [Materials Processing Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Singh, S.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2010-03-15

    Ni/Cu multilayers were electrodeposited from a single solution electrolyte by galvanostatic method. Interface roughness, magnetization and magneto-transport studies of Ni/Cu multilayers on Si(1 1 1)/Ti/Cu substrate were carried out for samples deposited from three different electrolytes, viz. pure sulphate, sulphate-citrate and sulphate-polyethylene glycol-8000 (PEG-8000). The top Ni-layer morphology of these samples was characterized by atomic force microscope (AFM). Detailed analysis of the morphological data showed a typical two-dimensional fractal growth pattern in all the three cases. The structural parameters like interface roughness, density and thicknesses of Ni and Cu layers were extracted from neutron reflectivity (NR) study. The order of interface roughness obtained from NR and AFM was found to be quite close. The sample deposited from sulphate-citrate electrolyte was found to have minimum interface roughness. The polarized neutron reflectometry (PNR) measurement showed reduced magnetic moment value ({approx}0.41 {+-} 0.01 {mu}{sub B}) for nickel layers compared to bulk value in all the three samples. The magnetoresistance (MR) of these samples were measured at room temperature. An attempt has been made to explain the observed MR results in terms of granular structure and scattering mechanism involving super-paramagnetic and ferromagnetic particles in these samples.

  6. Oleic acid coated magnetic nano-particles: Synthesis and characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Panda, Biswajit, E-mail: bpanda@mes.ac.in; Goyal, P. S. [Pillai’s Institute of Information Technology, Engineering, Media Studies and Research, Dr. K. M. Vasudevan Pillai’s Campus, New Panvel, 410 206 (India)

    2015-06-24

    Magnetic nano particles of Fe{sub 3}O{sub 4} coated with oleic acid were synthesized using wet chemical route, which involved co-precipitation of Fe{sup 2+} and Fe{sup 3+} ions. The nano particles were characterized using XRD, TEM, FTIR, TGA and VSM. X-ray diffraction studies showed that nano particles consist of single phase Fe{sub 3}O{sub 4} having inverse spinel structure. The particle size obtained from width of Bragg peak is about 12.6 nm. TEM analysis showed that sizes of nano particles are in range of 6 to 17 nm with a dominant population at 12 - 14 nm. FTIR and TGA analysis showed that -COOH group of oleic acid is bound to the surface of Fe{sub 3}O{sub 4} particles and one has to heat the sample to 278° C to remove the attached molecule from the surface. Further it was seen that Fe{sub 3}O{sub 4} particles exhibit super paramagnetism with a magnetization of about 53 emu/ gm.

  7. Oleic acid coated magnetic nano-particles: Synthesis and characterizations

    International Nuclear Information System (INIS)

    Magnetic nano particles of Fe3O4 coated with oleic acid were synthesized using wet chemical route, which involved co-precipitation of Fe2+ and Fe3+ ions. The nano particles were characterized using XRD, TEM, FTIR, TGA and VSM. X-ray diffraction studies showed that nano particles consist of single phase Fe3O4 having inverse spinel structure. The particle size obtained from width of Bragg peak is about 12.6 nm. TEM analysis showed that sizes of nano particles are in range of 6 to 17 nm with a dominant population at 12 - 14 nm. FTIR and TGA analysis showed that -COOH group of oleic acid is bound to the surface of Fe3O4 particles and one has to heat the sample to 278° C to remove the attached molecule from the surface. Further it was seen that Fe3O4 particles exhibit super paramagnetism with a magnetization of about 53 emu/ gm

  8. On the characterization of magnetic reconnection in global MHD simulations

    Directory of Open Access Journals (Sweden)

    T. V. Laitinen

    2006-11-01

    Full Text Available The conventional definition of reconnection rate as the electric field parallel to an x-line is problematic in global MHD simulations for several reasons: the x-line itself may be hard to find in a non-trivial geometry such as at the magnetopause, and the lack of realistic resistivity modelling leaves us without reliable non-convective electric field. In this article we describe reconnection characterization methods that avoid those problems and are practical to apply in global MHD simulations. We propose that the reconnection separator line can be identified as the region where magnetic field lines of different topological properties meet, rather than by local considerations. The global convection associated with reconnection is then quantified by calculating the transfer of mass, energy or magnetic field across the boundary of closed and open field line regions. The extent of the diffusion region is determined from the destruction of electromagnetic energy, given by the divergence of the Poynting vector. Integrals of this energy conversion provide a way to estimate the total reconnection efficiency.

  9. Acoustical characterization and parameter optimization of polymeric noise control materials

    Science.gov (United States)

    Homsi, Emile N.

    2003-10-01

    The sound transmission loss (STL) characteristics of polymer-based materials are considered. Analytical models that predict, characterize and optimize the STL of polymeric materials, with respect to physical parameters that affect performance, are developed for single layer panel configuration and adapted for layered panel construction with homogenous core. An optimum set of material parameters is selected and translated into practical applications for validation. Sound attenuating thermoplastic materials designed to be used as barrier systems in the automotive and consumer industries have certain acoustical characteristics that vary in function of the stiffness and density of the selected material. The validity and applicability of existing theory is explored, and since STL is influenced by factors such as the surface mass density of the panel's material, a method is modified to improve STL performance and optimize load-bearing attributes. An experimentally derived function is applied to the model for better correlation. In-phase and out-of-phase motion of top and bottom layers are considered. It was found that the layered construction of the co-injection type would exhibit fused planes at the interface and move in-phase. The model for the single layer case is adapted to the layered case where it would behave as a single panel. Primary physical parameters that affect STL are identified and manipulated. Theoretical analysis is linked to the resin's matrix attribute. High STL material with representative characteristics is evaluated versus standard resins. It was found that high STL could be achieved by altering materials' matrix and by integrating design solution in the low frequency range. A suggested numerical approach is described for STL evaluation of simple and complex geometries. In practice, validation on actual vehicle systems proved the adequacy of the acoustical characterization process.

  10. Dynamics expansion of laser produced plasma with different materials in magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Rabia Qindeel; Noriah Bte Bidin; Yaacob Mat daud [Laser Technology Laboratory, Physics Department, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)], E-mail: plasmaqindeel@yahoo.com

    2008-12-01

    The dynamics expansion of the plasma generated by laser ablation of different materials has been investigated. The dynamics and confinement of laser generated plasma plumes are expanding across variable magnetic fields. A Q-switched neodymium-doped yttrium aluminum garnet laser with 1064 nm, 8 ns pulse width and 0.125 J laser energy was used to generate plasma that was allowed to expand across variable magnetic within 0.1 - 0.8 T. The expansions of laser-produced plasma of different materials are characterized by using constant laser power. CCD video camera was used to visualize and record the activities in the focal region. The plasma plume length, width and area were measured by using Matrox Inpector 2.1 and video Test 0.5 software. Spectrums of plasma beam from different materials are studied via spectrometer. The results show that the plasma generated by aluminum target is the largest than Brass and copper. The optical radiation from laser generated plasma beam spectrums are obtained in the range of UV to visible light.

  11. Fabrication and characterization of modified-hydroxyapatite/polyetheretherketone coating materials

    International Nuclear Information System (INIS)

    Highlights: • 45 wt%-Hydroxyaptite/polyetheretherketone (HA/PEEK) coating materials modified by silane coupling agent (KH560) on PEEK substrate is successfully fabricated by solution casting method. • Strong bonding between the composite coating and the PEEK substrate is achieved. • HA/PEEK coating materials exhibit better bioactivity. - Abstract: 45 wt%-Hydroxyaptite/polyetheretherketone (HA/PEEK) coating materials modified by silane coupling agent (KH560) on PEEK substrate were successfully fabricated by solution casting method and characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and tensile testing. The modified HA fillers were obtained to be uniformly distributed in the HA/PEEK coating, which has better properties of tensile strength and fracture toughness than those of the unmodified specimen. A good bonding between the composite coating and the PEEK substrate was achieved by solution casting method, resulting in integral-fracture without falling apart or delaminating during tensile loading. The modified specimens dipped into simulated body fluid (SBF) were characterized by SEM, XRD and FTIR, indicating that the bioactivity of the dipped materials was demonstrated more apparent with extending the dipping time. Therefore, the coating materials may become the substitutes for the hard tissues of the human body in the future, which could realize the balance between the mechanical properties and the bioactivity by modifying the structural design of the coating

  12. Fabrication and characterization of modified-hydroxyapatite/polyetheretherketone coating materials

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Rui [College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); Fang, Lin, E-mail: fanglinhit@163.com [College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); Luo, Zhongkuan [College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); Zheng, Ruisheng [College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Song, Shenhua; Weng, Luqian; Lei, JinPing [Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China)

    2014-09-30

    Highlights: • 45 wt%-Hydroxyaptite/polyetheretherketone (HA/PEEK) coating materials modified by silane coupling agent (KH560) on PEEK substrate is successfully fabricated by solution casting method. • Strong bonding between the composite coating and the PEEK substrate is achieved. • HA/PEEK coating materials exhibit better bioactivity. - Abstract: 45 wt%-Hydroxyaptite/polyetheretherketone (HA/PEEK) coating materials modified by silane coupling agent (KH560) on PEEK substrate were successfully fabricated by solution casting method and characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and tensile testing. The modified HA fillers were obtained to be uniformly distributed in the HA/PEEK coating, which has better properties of tensile strength and fracture toughness than those of the unmodified specimen. A good bonding between the composite coating and the PEEK substrate was achieved by solution casting method, resulting in integral-fracture without falling apart or delaminating during tensile loading. The modified specimens dipped into simulated body fluid (SBF) were characterized by SEM, XRD and FTIR, indicating that the bioactivity of the dipped materials was demonstrated more apparent with extending the dipping time. Therefore, the coating materials may become the substitutes for the hard tissues of the human body in the future, which could realize the balance between the mechanical properties and the bioactivity by modifying the structural design of the coating.

  13. Preparation and characterization of hydroxyapatite from unusual materials

    International Nuclear Information System (INIS)

    The goal of this work is to investigate the synthesis of hydroxyapatite, starting from natural or unusual materials. As first stage, a synthesis was carried out using calcium carbonate from biological material. The purpose of this study is the production of pure, fine hydroxyapatite powder, in the order to get further good compaction and sintering. Several attempts were developed, searching some parameters like homogenizing and heating time as well as temperature, for the best performance. The products were characterized by X-ray diffraction and infrared spectroscopy. (author)

  14. Synthesis and characterization of Bi-Te-Se thermoelectric materials

    International Nuclear Information System (INIS)

    Bismuth Telluride (Bi2Te3) and its related alloys act as a promising thermoelectric material and preferred over other thermoelectric materials due to their high stability and efficiency under ambient conditions. In the present work, we have reported economical, environment friendly and low-temperature aqueous chemical method for the synthesis of Bi-Se-Te alloy. The prepared samples are characterized by X-Ray Diffraction to investigate the structural properties and UV-Visible spectroscopy for the spectroscopic analysis. The absorption spectrum reveals the sensitivity in the ultraviolet as well as in visible region

  15. Electrical, dielectric and magnetic characterization of Bi–Cr substituted M-type strontium hexaferrite nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Shakoor, Sajeela [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan-60800 (Pakistan); Ashiq, Muhammad Naeem, E-mail: naeemashiqqau@yahoo.com [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan-60800 (Pakistan); Malana, Muhammad Aslam [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan-60800 (Pakistan); Mahmood, Azhar; Warsi, Muhammad Farooq [Department of Chemistry, The Islamia University, Bahawalpur (Pakistan); Najam-ul-Haq, Muhammad; Karamat, Nazia [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan-60800 (Pakistan)

    2014-08-01

    Strontium hexaferrite nanoparticles substituted with bismuth and chromium having nominal composition SrFe{sub 12−2x}Bi{sub x}Cr{sub x}O{sub 19} (x=0.2, 0.4, 0.6, 0.8) have been synthesized by the sol–gel method. The samples are characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), DC electrical resistivity, magnetic and dielectric measurements. The XRD data shows that the nanoparticles are crystallized into single hexagonal magnetoplumbite phase. Room temperature DC electrical resistivity decreases on increasing the Bi–Cr contents. The dielectric constant, dielectric loss and tangent loss decrease with the frequency. The magnetic properties such as saturation magnetization (M{sub s}), remanence (M{sub r}) and coercivity (H{sub c}) increase with increasing the dopant concentration up to x=0.2 and then decrease with further increase in dopant content. Coercivity decreases with increasing the dopant content up to x=0.2 then increases with further increase in dopant content. The increase in M{sub s} and M{sub r} while decrease in H{sub c} indicates that the material with composition SrBi{sub 0.2}Cr{sub 0.2}Fe{sub 11.6}O{sub 19} is suitable for magnetic recording media. - Highlights: • Sol–gel method has been employed for the synthesis of single phase hexaferrites nanomaterials. • Dielectric parameters show some relaxation behavior at high frequencies. • We are able to improve the saturation magnetization and remanence. • The synthesized materials are beneficial for recording media.

  16. Knitted radar absorbing materials (RAM) based on nickel-cobalt magnetic materials

    Science.gov (United States)

    Teber, Ahmet; Unver, Ibrahim; Kavas, Huseyin; Aktas, Bekir; Bansal, Rajeev

    2016-05-01

    There has been a long-standing interest in the development of flexible, lightweight, thin, and reconfigurable radar absorbing materials (RAM) for military applications such as camouflaging ground-based hardware against airborne radar observation. The use of polymeric Polyacrylonitrile (PAN) fabrics as a host matrix for magnetic metal nano-particles (either at the yarn-stage or after weaving the fabric) for shielding and absorbing applications has been described in the literature. In our experimental investigation, the relative concentrations of Nickel and Cobalt as well as the coating time are varied with a view to optimizing the microwave absorption characteristics of the resulting PAN-based composite material in the radar-frequency bands (X, Ku, and K). It is found that the PAN samples with the shortest coating time have the best return losses (under -20 dB return loss over a moderate bandwidth).

  17. Secondary emission yield at low-primary energies of magnetic materials for anti-multipactor applications

    CERN Document Server

    Aguilera, L; Olano, L; Casas, A; Morales, P; Vázquez, M; Galán, L; Caspers, F; Costa-Pinto, P; Taborelli, M; Raboso, D

    2014-01-01

    Secondary electron emission processes under electron bombardment are central to many effects at surfaces and interfaces, and to many in vacuum high power RF electronic devices where multipactor can be very intense [1,2]. Ferrite materials are usually used in microwave components used in space telecommunication systems, as circulators, phase-shifters, switches, and isolators. The physics of the multipactor phenomenon existing in microwave devices based on ferrite materials is an important issue and it is urgent to be researched [3]. One difficulty in the analysis of the multipactor effect in RF components containing ferrite lies on the fact that this material is an anysotropic magnetic medium controlled by an applied permanent magnetic field, which is used to magnetize the ferrite material. SEY and other properties (structure, magnetic behaviour,...) of soft-magnetic materials were studied in this work. MnZn soft ferrites magnets are suitable in the situation of frequency < 3MHz, low loss and high μi. Comp...

  18. Magnetic mesoporous material for the sequestration of algae

    Science.gov (United States)

    Trewyn, Brian G.; Kandel, Kapil; Slowing, Igor Ivan; Lee, Show-Ling

    2014-09-09

    The present invention provides a magnetic mesoporous nanoparticle that includes a mesoporous silicate nanoparticle and iron oxide. The present invention also provides a method of using magnetic mesoporous nanoparticles to sequester microorganisms from a media.

  19. Synthesis and characterization of magnetic carbon nanotubes/silsesquioxane nanocomposite thin films

    Science.gov (United States)

    Osorio, Alice Gonçalves; Machado, Geraldo Beyer; Pereira, Marcelo Barbalho; Benvenutti, Edilson Valmir; Pereira, Luis Gustavo; Bergmann, Carlos Perez; Oliveira, Artur Harres de; Costa, Tania Maria Haas

    2016-05-01

    In the present study, magnetic carbon nanotubes (CNTs)/silsesquioxane nanocomposites were produced by sol-gel method and deposited as thin film by dip-coating process. Blank films and films with CNTs were characterized in order to evaluate their chemical composition and morphology. Profilometry technique showed the formation of films with 305 ± 22 nm of thickness for blank samples (without CNTs) and 173 ± 05 nm thickness for samples with CNTs. Microscopy techniques indicated the presence of CNTs well dispersed in the films and, with the aid of Raman and Fourier Transform Infrared spectroscopy, chemical composition of silsesquioxane matrix was evidenced and the presence of CNTs was confirmed in the films. Finally, the magnetic response of the deposited films was analyzed by Alternating Gradient-Field Magnetometer and results indicated that films reinforced with CNTs showed a hysteresis loop that indicates a coercivity of 103 Oe and the blank film did not show any significant response to the field applied. Hence, the authors suggest that this hybrid organic-inorganic material has potential to be applied as a new material for magnetic storage.

  20. Synthesis and characterization of new polymeric materials for advanced applications

    OpenAIRE

    Sanna, Roberta

    2014-01-01

    The main aim of this thesis was to synthesize and characterize new kinds of polymeric nanocomposite materials, including stimuli responsive hydrogels, organic-inorganic interpenetrating polymer networks, polyacrylates and polyurethanes. Specifically, this work was divided in two main threads: in the first one, electric field-, ionic force-, pH- and thermo-responsive hydrogels were prepared, whose thermal and mechanical properties, as well as the swelling behavior were strongly improved by the...

  1. Synthesis, Characterization and Pore Structure Analysis of Mesoporous Materials

    OpenAIRE

    Saldarriaga Lopez, Laura Carolina

    2014-01-01

    Self-assembly provides a route to make mesoporous structures that have accessible internal surface area. These types of materials show promise for use in opto-electronic devices as well as for energy storage devices. In this work we synthesize a range of mesoporous thin films from molecular and nanocrystal precursors. We characterize these films' porous structure and surface area using ellipsometric-porosimetry. This work is divided into three parts; the first section focuses on synthesizing ...

  2. Characterization of the material response in the granular ratcheting

    OpenAIRE

    García-Rojo, R.; Alonso-Marroquín, F.; Herrmann, H. J.

    2005-01-01

    The existence of a very special ratcheting regime has recently been reported in a granular packing subjected to cyclic loading \\cite{alonso04}. In this state, the system accumulates a small permanent deformation after each cycle. After a short transient regime, the value of this permanent strain accumulation becomes independent on the number of cycles. We show that a characterization of the material response in this peculiar state is possible in terms of three simple macroscopic variables. Th...

  3. Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Clapsaddle, B; Gash, A; Plantier, K; Pantoya, M; Jr., J S; Simpson, R

    2004-04-27

    In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. By introducing a fuel metal, such as aluminum, into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. In addition, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. These organic additives can cause the generation of gas upon ignition of the materials, therefore resulting in a composite material that can perform pressure/volume work. Furthermore, the desired organic functionality is well dispersed throughout the composite material on the nanoscale with the other components, and is therefore subject to the same increased reaction kinetics. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of iron(III) oxide/organosilicon oxide nanocomposites and their performance as energetic materials will be discussed.

  4. Characterization of the damage produced on different materials surfaces

    International Nuclear Information System (INIS)

    In the present work the characterization techniques of surfaces ULOI and RIMAPS have been applied on laboratory samples made from aluminium, stainless steel and material based on fiberglass.The resultant surfaces of, chemical etching with corrosive agents Keller and Tucker, mechanic damage from the wear and tear of abrasive paper and sandrubbing with alumina particles, are analyzed to different level of damage.The systematic application of the above mentioned techniques is carried out with the objective of finding information, which allows to characterize the superficial damage, both in its incipient state as in the extreme situation revealed by the presence of etch pits. Important results have been obtained, in the characterization of the incipient stage of the chemical etching, using the curves of the normalized area.In addition, it was possible to verify the capacity of the techniques in the early detection of the preferential directions generated by the etch pits

  5. Characterization of spent fuel approved testing material--ATM-104

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, R.J.; Blahnik, D.E.; Jenquin, U.P.; Mendel, J.E.; Thomas, L.E.; Thornhill, C.K.

    1991-12-01

    The characterization data obtained to date are described for Approved Testing Material 104 (ATM-104), which is spent fuel from Assembly DO47 of the Calvert Cliffs Nuclear Power Plant (Unit 1), a pressurized-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-104 consists of 128 full-length irradiated fuel rods with rod-average burnups of about 42 MWd/kgM and expected fission gas release of about 1%. A variety of analyses were performed to investigate cladding characteristics, radionuclide inventory, and redistribution of fission products. Characterization data include (1) fabricated fuel design, irradiation history, and subsequent storage and handling history; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) special fuel studies involving analytical transmission electron microscopy (AEM) and electron probe microanalyses (EPMA); (6) calculated nuclide inventories and radioactivities in the fuel and cladding; and (7) radiochemical analyses of the fuel and cladding.

  6. Characterization of spent fuel approved testing material--ATM-104

    International Nuclear Information System (INIS)

    The characterization data obtained to date are described for Approved Testing Material 104 (ATM-104), which is spent fuel from Assembly DO47 of the Calvert Cliffs Nuclear Power Plant (Unit 1), a pressurized-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-104 consists of 128 full-length irradiated fuel rods with rod-average burnups of about 42 MWd/kgM and expected fission gas release of about 1%. A variety of analyses were performed to investigate cladding characteristics, radionuclide inventory, and redistribution of fission products. Characterization data include (1) fabricated fuel design, irradiation history, and subsequent storage and handling history; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) special fuel studies involving analytical transmission electron microscopy (AEM) and electron probe microanalyses (EPMA); (6) calculated nuclide inventories and radioactivities in the fuel and cladding; and (7) radiochemical analyses of the fuel and cladding

  7. Characterization of spent fuel approved testing material: ATM-106

    International Nuclear Information System (INIS)

    The characterization data obtained to date are described for Approved Testing Material (ATM)-106 spent fuel from Assembly BT03 of pressurized-water reactor Calvert Cliffs No. 1. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well- characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCWRM) program. ATM-106 consists of 20 full-length irradiated fuel rods with rod-average burnups of about 3700 GJ/kgM (43 MWd/kgM) and expected fission gas release of /approximately/10%. Characterization data include (1) as-fabricated fuel design, irradiation history, and subsequent storage and handling; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) calculated nuclide inventories and radioactivities in the fuel and cladding; and (6) radiochemical analyses of the fuel and cladding. Additional analyses of the fuel rod are being conducted and will be included in planned revisions of this report. 12 refs., 110 figs., 81 tabs

  8. Characterization of spent fuel approved testing material---ATM-105

    International Nuclear Information System (INIS)

    The characterization data obtained to data are described for Approved Testing Material 105 (ATM-105), which is spent fuel from Bundles CZ346 and CZ348 of the Cooper Nuclear Power Plant, a boiling-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-105 consists of 88 full-length irradiated fuel rods with rod-average burnups of about 2400 GJ/kgM (28 MWd/kgM) and expected fission gas release of about 1%. Characterization data include (1) descriptions of as-fabricated fuel design, irradiation history, and subsequent storage and handling; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) special fuel studies involving analytical transmission electron microscopy (AEM); (6) calculated nuclide inventories and radioactivities in the fuel and cladding; and (7) radiochemical analyses of the fuel and cladding. Additional analyses of the fuel are being conducted and will be included in planned revisions of this report

  9. A novel method for material characterization of reusable products.

    Science.gov (United States)

    Fortuna, Lorena M; Diyamandoglu, Vasil

    2016-06-01

    Product reuse contributes favorably to waste management and resource recovery by diverting products from terminal disposal to second-hand urban markets. Many organizations with social mission incorporate in their activities the process of reuse, thus making valuable products available to second-hand customers through their thrift stores. Data management and product classification are an important aspect of quantitative analysis of second-hand products circulating through reuse organizations. The New York City Center for Materials Reuse has, for the last 10years, organized the reuse activities of most not for profit organizations, and collected valuable information on the strengths and weaknesses of their operations. One such finding is the casual, and inconsistent approach used by these organizations to keep a record of the level and value of the reuse efforts they undertake. This paper describes a novel methodology developed to standardize record keeping and characterize commonly reused post-consumer products by assessing the outgoing product flow from reuse organizations. The approach groups material composition of individual products into main product categories, creating a simplified method to characterize products. Furthermore, by linking product categories and material composition, the method creates a matrix to help identify the material composition of products handled by reuse organizations. As part of the methodology, whenever adequate data are not available about certain types of products, a process identified as "field characterization study" is proposed and incorporated in the implementation to develop meaningful and useful data on the weight and material composition. Finally, the method incorporates the estimation of the environmental impact of reuse using standard models available through the U.S. Environmental Protection Agency and other worldwide entities. The diversified weight and size of products poses a challenge to the statistical significance

  10. Material Characterization of Fatigue Specimens made from Meta-stable Austenitic Stainless Steel

    International Nuclear Information System (INIS)

    The main objective of the EU-project CRETE (Contract No.: FIS5-1999-00280) was to assess the capability and the reliability of innovative NDT-inspection techniques for the detection of material degradation, induced by thermal fatigue and neutron irradiation, of metastable austenitic and ferritic low-alloy steel. Several project partners tested aged or irradiated samples, using various techniques (acoustic, magnetic and thermoelectric). However, these indirect methods require a careful interpretation of the measured signal in terms of micro-structural evolutions due to ageing of the material. Therefore the material had to be characterized in its undamaged, as well as in its damaged state. The present report summarises only the material characterization of the fatigue specimens. It is issued simultaneously as an PSI Bericht and the CRETE work package 3 (WP3) report. Each partner according to their own specifications purchased three materials under investigation, namely AISI 347, AISI 321 and AISI 304L. After sending the material to PSI, all fatigue specimens were manufactured by the same Swiss company. Each partner was responsible for his fatigue tests which are documented in the report WP1, written by FANP. In order to characterize the material in its unfatigued as well as in its fatigued state and to consider microstructural changes related to fatigue damage the methods listed below were employed either by PSI or by INSA de Lyon: (1) Inductive Coupled Plasma Emission Photometry (ICP-OES) was applied to determine the chemical composition, (2) Scanning electron microscopy (SEM) for observing cracks, slip bands between grain and twin boundaries, - Ferromaster for measuring the magnetic permeability, (3) Physical Properties Measuring System (PPMS) for measuring magnetization characteristics, (4) Neutron- and advanced X-ray diffraction methods for the quantitative determination of martensite, - Transmission electron microscopy (TEM) for the observation of crystalline

  11. Magnetic characterization of surface-coated magnetic nanoparticles for biomedical application

    Energy Technology Data Exchange (ETDEWEB)

    Tomitaka, Asahi, E-mail: d09sd105@ynu.ac.j [Department of Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan); Koshi, Tomohiro; Hatsugai, Shinsuke; Yamada, Tsutomu; Takemura, Yasushi [Department of Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2011-05-15

    The influence of the oleic acid surface coating on Fe{sub 3}O{sub 4} and NiFe{sub 2}O{sub 4} nanoparticles on their magnetic and calorimetric characterization was investigated. Fe{sub 3}O{sub 4} nanoparticles (particle sizes of 15-20 and 20-30 nm) and NiFe{sub 2}O{sub 4} nanoparticles (particle sizes of 20-30 nm) were dispersed in oleic acid. The surface coating resulted in a decrease in the dipole-dipole interaction between the particles, which in turn affected the coercivity and heat dissipation of the nanoparticles. The coercivity of the oleic-acid-coated nanoparticles was found to be lower than that of the uncoated nanoparticles. The temperature rise in the oleic-acid-coated nanoparticles was greater than that of the uncoated nanoparticles; this temperature rise was associated with the relaxation losses. The viscosity dependence on the self-heating temperature of Fe{sub 3}O{sub 4} nanoparticles (15-20 and 20-30 nm) under an ac magnetic field was measured. The temperature rise for both the Fe{sub 3}O{sub 4} nanoparticles (15-20 and 20-30 nm) exhibited a strong dependence on viscosity at each magnetic field frequency, and the contribution of Brownian relaxation loss to the temperature rise was revealed. Moreover, an in vitro cytotoxicity test of Fe{sub 3}O{sub 4} and NiFe{sub 2}O{sub 4} was performed using human cervical carcinoma cells (HeLa), and the cytotoxicity of NiFe{sub 2}O{sub 4} nanoparticles was compared to that of Fe{sub 3}O{sub 4} nanoparticles. - Research Highlights: Oleic acid coating reduced coercivity of magnetic nanoparticles. Oleic acid coating increased heat dissipation of magnetic nanoparticles. Heat dissipation of magnetic nanoparticles depended on surrounding viscosity. NiFe{sub 2}O{sub 4} nanoparticles caused viability reduction on HeLa cells.

  12. NMR study of domain wall pinning in a magnetically ordered material

    Science.gov (United States)

    Pleshakov, I. V.; Popov, P. S.; Kuz'min, Yu. I.; Dudkin, V. I.

    2016-01-01

    The use of nuclear magnetic resonance in the form of spin echo in combination with magnetic field pulses applied to a magnetically ordered material sample offers a convenient tool for studying characteristics of the centers of domain-wall pinning. Possibilities of this method have been demonstrated in experiments with lithium-zinc ferrite.

  13. Structure and magnetic properties of SiO2/PCL novel sol–gel organic–inorganic hybrid materials

    International Nuclear Information System (INIS)

    Organic–inorganic nanocomposite materials have been synthesized via sol–gel. They consist of an inorganic SiO2 matrix, in which different percentages of poly(ε-caprolactone) (PCL) have been incorporated. The formation of H-bonds among the carbonyl groups of the polymer chains and Si–OH group of the inorganic matrix has been proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis and has been confirmed by solid-state nuclear magnetic resonance (NMR). X-Ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscope (SEM) micrograph and atomic force microscope (AFM) topography showed their homogeneous morphology and nanostructure nature. Considering the opportunity to synthesize these hybrid materials under microgravity conditions by means of magnetic levitation, superconducting quantum interference device (SQUID) magnetometry has been used to quantify their magnetic susceptibility. This measure has shown that the SiO2/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount. - Graphical abstract: Characterization and magnetic properties of SiO2/PCL organic–inorganic hybrid materials synthesized via sol–gel. FT-IR, Fourier transform infrared spectroscopy; solid-state NMR: solid-state nuclear magnetic resonance; SQUID: superconducting quantum interference device. - Highlights: • Sol–gel synthesis of SiO2/PCL amorphous class I organic–inorganic hybrid materials. • FT-IR and NMR analyses show the hydrogen bonds formation between SiO2 and PCL. • AFM and SEM analyses confirm that the SiO2/PCL are homogenous hybrid materials. • The SQUID measures show that the simples are diamagnetic. • Diamagnetic susceptibility of SiO2/PCL materials increases with the PCL amount

  14. Preparation, characterization and certification of uranium isotope reference materials

    International Nuclear Information System (INIS)

    This work describes the preparation, characterization and certification of a set of uranium isotope reference materials ranging from 0.5 to 20.0 % of 235U in mass. The most important concepts of metrology in chemical measurements were applied so that the certified quantities in these materials could be directly traceable to the International System of Units (SI). As a consequence of this approach, these materials can be used in the instruments calibration, estimation of measurement uncertainty, method validation, assessment of performance of analysts, quality control routines and interlaboratory comparison programmes. The most advanced methods and techniques in mass spectrometry, that is, gas source mass spectrometry (GSMS), thermal ionisation mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICPMS) were investigated to identify which are the dominant components in the uncertainty and to quantify its contribution to the final value of the measurement uncertainty of the isotopic ratio. The results obtained were then compared to verify which are the methods and techniques associated to the lowest measurement uncertainty values. The isotope amount ratio n(235U)/n(238U) was certified in the materials produced to expanded uncertainties ranging from 0.02 to 0.10 % and the ratios n(234U)/n(238U) and n(236U)/n(238U), to uncertainties ranging from 0.03 to 2.20 %. These values fully comply to the requirements of the isotopic characterization of nuclear fuel as well as the analysis of environmental samples for nuclear safeguards. (author)

  15. Characterization of polymer materials and powders for selective laser melting

    Science.gov (United States)

    Wudy, K.; Drummer, D.; Drexler, M.

    2014-05-01

    Concerning individualization, the requirements to products have increased. The trend towards individualized serial products faces manufacturing techniques with demands of increasing flexibility. Additive manufacturing techniques generate components directly out of a CAD data set while requiring no specific tool or form. Due to this additive manufacturing processes comply, in opposite to conventional techniques, with these increased demands on processing technology. With a variety of available additive manufacturing techniques, some of them have a high potential to generate series products with reproducible properties. Selective laser melting (SLM) of powder materials shows the highest potential for this application. If components made by SLM are desired to be applied in technical series products, their achievable properties play a major part. These properties are mainly determined by the processed materials. The range of present commercially available materials for SLM of polymer powders is limited. This paper shows interrelations of various material properties to create a basic understanding of sintering processes and additional qualifying new materials. Main properties of polymer materials, with regard to their consolidation are viscosity and surface energy. On the one hand the difference of the surface energy between powder and melt influences, the wetting behavior, and thus the penetration depth. On the other hand, a high surface tension is fundamental for good coalescence of bordering particles. To fulfill these requirements limits of the surface tension will be determined on the basis of a reference material. For these reason methods for determining surface tension of solids, powders and melts are analyzed, to carry out a possible process-related material characterization. Not only an insight into observed SLM phenomena is provided but also hints concerning suitable material selection.

  16. A Smart Polymer Composite Based on a NiTi Ribbon and a Magnetic Hybrid Material for Actuators with Multiphysic Transduction

    Directory of Open Access Journals (Sweden)

    Beatriz López-Walle

    2015-12-01

    Full Text Available A smart composite material constituted of a magnetic hybrid film and a NiTi shape memory alloy (SMA ribbon was obtained and characterized. The magnetic hybrid film was joined to the NiTi ribbon in order to combine the properties of both materials. This new composite material combines magnetic properties of the hybrid film, (Fe2O3-CMC/(polyvinyl butyral, and the shape memory properties of the NiTi ribbon, which has a chemical composition of Ti-50.13 at. % Ni. This smart composite material has a mass of 18.3% NiTi ribbon and 81.7% magnetic hybrid film. Results obtained by DSC show that the smart composite material presents a small delay of transformation during warming and cooling because the magnetic hybrid film acts like a thermal insulator. Thermomechanical results indicate that the hybrid material also acts as a mechanical reinforcement, since it is observed that the Stress-Assisted Two-Way Memory Effect (SATWME of the smart composite is lower than the SATWME of the SMA ribbon. The density current values of phase transformations were clearly identified with a thermomechanical apparatus developed in our laboratory. Finally, displacements of the smart composite material in cantilever configuration are obtained by applying an external magnetic field. All these results demonstrate that the smart composite material can be activated by temperature, electrical current, stress, and/or magnetic field, offering good expectations for actuating applications with multiphysic transduction.

  17. Eddy current-shielded x-space relaxometer for sensitive magnetic nanoparticle characterization.

    Science.gov (United States)

    Bauer, L M; Hensley, D W; Zheng, B; Tay, Z W; Goodwill, P W; Griswold, M A; Conolly, S M

    2016-05-01

    The development of magnetic particle imaging (MPI) has created a need for optimized magnetic nanoparticles. Magnetic particle relaxometry is an excellent tool for characterizing potential tracers for MPI. In this paper, we describe the design and construction of a high-throughput tabletop relaxometer that is able to make sensitive measurements of MPI tracers without the need for a dedicated shield room. PMID:27250472

  18. Materials characterization center workshop on corrosion of engineered barriers

    International Nuclear Information System (INIS)

    A workshop on corrosion test procedures for materials to be used as barriers in nuclear waste repositories was conducted August 19 and 20, 1980, at the Battelle Seattle Research Center. The purpose of the meeting was to obtain guidance for the Materials Characterization Center in preparing test procedures to be approved by the Materials Review Board. The workshop identified test procedures that address failure modes of uniform corrosion, pitting and crevice corrosion, stress corrosion, and hydrogen effects that can cause delayed failures. The principal areas that will require further consideration beyond current engineering practices involve the analyses of pitting, crevice corrosion, and stress corrosion, especially with respect to quantitative predictions of the lifetime of barriers. Special techniques involving accelerated corrosion testing for uniform attack will require development

  19. Electrical Characterizations of Lightning Strike Protection Techniques for Composite Materials

    Science.gov (United States)

    Szatkowski, George N.; Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Mielnik, John J.

    2009-01-01

    The growing application of composite materials in commercial aircraft manufacturing has significantly increased the risk of aircraft damage from lightning strikes. Composite aircraft designs require new mitigation strategies and engineering practices to maintain the same level of safety and protection as achieved by conductive aluminum skinned aircraft. Researchers working under the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project are investigating lightning damage on composite materials to support the development of new mitigation, diagnosis & prognosis techniques to overcome the increased challenges associated with lightning protection on composite aircraft. This paper provides an overview of the electrical characterizations being performed to support IVHM lightning damage diagnosis research on composite materials at the NASA Langley Research Center.

  20. Quantitative characterization of magnetic separators: Comparison of systems with and without integrated microfluidic mixers

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Bruus, Henrik; Hansen, Mikkel Fougt

    2006-01-01

    We present two new types of microfluidic passive magnetic bead separator systems as well as methods for performing quantitative characterizations of them. Both systems consist of a microfluidic channel with long rectangular magnetic elements of permalloy that are placed by the sides of the channel...... and magnetized by an external magnetic field. In one of the systems, a staggered herringbone microfluidic mixer is integrated in the channel. The characterization of the systems includes magnetic measurements of the capture-and-release efficiencies, estimates of distributions of captured beads in a...

  1. A soft magnetic material for power supply systems of high energy physics experiments

    Directory of Open Access Journals (Sweden)

    Ghisolfi E.

    2013-01-01

    Full Text Available Most of the high energy physics experiments require their detectors to be embedded in a high intensity magnetic field. In particular the biggest of them, ATLAS, running in the CERN Large Hadron Collider (LHC particle accelerator, generates a field of 2 T by means of a gigantic toroidal magnet working in open air. Its future phase 2 upgrade plans to move the DC/DC power supplies from the present positions on the external balconies directly on the detectors, where the field is of the order of 1 T. This presentation describes the development of samples made of special magnetic material for inductor cores suitable to work in such an environment. Starting from iron-silicon powders, at FN plant a plastic forming process, based on powder extrusion, injection moulding and sintering, was developed. To get the best compromise between the forming process requirements (good coupling among the metallic powder and the organic components to assure the right mouldability and the debinding and sintering conditions, several mixtures (with different percentages and kind of organic additives were experimented. A proper mould was designed and realized to get torous-shaped prototypes. The preliminary results of the physical-microstructural characterization performed on the first prototypes made will be shown.

  2. Development of P/M Fe–P soft magnetic materials

    Indian Academy of Sciences (India)

    S K Chaurasia; Ujjwal Prakash; P S Misra; K Chandra

    2012-04-01

    Phosphorous is treated as an impurity in conventional steels owing to segregation of phosphorous and formation of brittle phosphides along the grain boundaries. It is responsible for cold and hot shortness in wrought steels. In conventional powder metallurgy, involving compaction and sintering, high phosphorous content (up to 0.7%) in Fe-based alloys exhibit attractive set ofmechanical andmagnetic properties. These powder-processed alloys suffer from increasing volumetric shrinkage during sintering as phosphorous is increased beyond 0.6%. Thus both cast as well as conventional powder metallurgy routes have their own limitations in dealing with iron–phosphorous alloys. Hot-powder forging was used in the present investigation for the development of high-density soft magnetic materials containing 0.3–0.8% phosphorous to overcome these difficulties. It was observed that phosphorous addition improves the final density of the resulting product. It was further observed that hot-forged iron–phosphorous alloys have excellent hot/cold workability and could be easily shaped to thin strips (0.5–1.0 mm thick) and wires (0.5–1.0 mm diameter). The powder hot-forged alloys were characterized in terms of microstructure, porosity content/densification, hardness, softmagnetic properties and electrical resistivity.Magnetic properties such as coercivity 0.35–1.24 Oe, saturation magnetization 14145–17490 G and retentivity 6402–10836 G were observed. The obtained results were discussed based on the microstructures evolved.

  3. The Experimental Analysis on the Thermal and Electrical Characteristics of Impregnating Materials for Superconducting Magnets

    International Nuclear Information System (INIS)

    In recent years, a development of Coated Conductor (CC) that is a called the second generation superconductor tape is opened out. Therefore a commercialization of superconducting power equipments will be realized presently. To realize a commercialization, it is necessary to develop a stable superconducting magnet. A superconducting magnet has to keep thermal stability as well as electrical stability. In this paper, thermal conductivity of impregnating materials, epoxy compounds, was measured at 65K, 77K, 100K and 200K. Dielectric Strength of superconducting magnet modeled electrode system with impregnating materials was also analyzed. Stycast[reg] blue/catalyst 23LV is good materials to apply to the superconducting magnets

  4. Nano-magnetic material in the radula teeth of chiton Acan-thochiton rubrolinestus Lischke

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this note, relationships among the components, structure distribution and easy magnetization direction, structure of magnetic domain of nano-magnetic material in the major mature lateral radula teeth of chiton A.rubrolinestus Lischke are probed by using the high resolution transmission electron microscope (HRTEM), the scanning electron microscope (SEM), the magnetic force microscope (MFM) and the super-conducting quantum interference device (SQUID) magnetometer from the point of view of magnetism to provide a basis for comprehending biologic function of the magnetic radula.``

  5. Evaluation of magnetic material by using small-angle neutron scattering method

    International Nuclear Information System (INIS)

    The scattering of thermal and cold neutron beams has made many important contributions to condensed matter physics, particularly to elucidation of magnetism in condensed matter. In the small-angle neutron scattering experiment, the scattering around the direct beam is measured. The scattering is caused by the variation of scattering length density over distances, which exceed the normal interatomic spacings in condensed matter. Magnetic small particles in liquid or solid solution, magnetic inhomogeneous structures (e.g. magnetic alloys), magnetic fluctuation, helical spin structures, etc. are all investigated by the small-angle neutron scattering method. In this article, the method for evaluation of magnetic material is described. (author)

  6. Processing and characterization of novel biobased and biodegradable materials

    Science.gov (United States)

    Pilla, Srikanth

    are also capable of mass-producing foamed plastics with less material and less energy. Injection-molded or extruded components based on a number of different formulations were characterized extensively using various techniques such as tensile testing, dynamical mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, electron microscopy (scanning and transmission), and density and molecular weight measurement, etc. Ultimately, the composition-processing-structure-property relationships in five material systems have been established.

  7. Hybrid Nd-Fe-B/barium ferrite magnetic materials with epoxy matrix

    OpenAIRE

    Stajčić Aleksandar P.; Stajić-Trošić Jasna T.; Aleksić Radoslav R.; Žák Tomáš; Lazić Nada L.; Stijepović Mirko Z.; Grujić Aleksandar S.

    2012-01-01

    Lately a great attention has been paid to the research of bonded hybrid composites with improved dynamic mechanical capacities capable of replacing bonded Nd-Fe-B magnetic materials, by using the cheaper (ferrite) materials instead of the Nd-Fe-B powder while retaining the satisfying values of the maximal magnetic energy. The objective of this study is to assess how different contents of Nd-Fe-B and/or barium ferrite particles can affect morphological, dynamic mechanical and magnetic pr...

  8. Characterization of Li4Ti5O12 and LiMn2O4 spinel materials treated with aqueous acidic solutions

    NARCIS (Netherlands)

    Simon, D.R.

    2007-01-01

    In this thesis an investigation of two spinel materials, Li4Ti5O12 and LiMn2O4 used for Li-ion battery applications is performed interms of formation and reactivity towards acidic solutions. Subsequent characterizations such as structural, magnetic, chemical, and electrochemical characterizations ar

  9. Influence of processing on structure property correlations in τ-MnAl rare-earth free permanent magnet material

    International Nuclear Information System (INIS)

    Highlights: • The reported magnetic properties of τ-MnAl show a significant scatter in their data. • We report the synthesis of τ-MnAl employing different processing routes. • The observed magnetic properties were correlated with the synthesis route. • The resulting microstructure has been correlated with the magnetic properties. - Abstract: In order to understand the genesis of the magnetic τ-phase of MnAl alloy, which due to its multiphase nature is generally difficult to synthesize as a single-phase, we have synthesized it employing three different materials processing routes, namely, arc melting, mechanical alloying, and a combination of these two. Structural and microstructural characterizations employing X-ray diffraction and high resolution transmission electron microscopy demonstrate that irrespective of the material processing route employed, the formation of τ-MnAl phase was always accompanied by other non-magnetic phases, e.g., β-MnAl and γ-MnAl. However, the relative fraction of these phases was found to be dependent on the materials processing route and hence on the grain size of the parent phase. The arc melted alloy had the largest grain size and the highest fraction of the τ-MnAl phase, while the alloy prepared by mechanical alloying showed the smallest grain size and the lowest fraction of the magnetic phase. The largest value of Curie temperature, magnetic moment, coercivity and remanence were observed in the sample prepared by a combination of arc melting and mechanical alloying. Our results suggest that in addition to the τ-MnAl phase fraction the magnetic properties could be related to the density of structural defects

  10. Synthesis, characterization and magnetic behavior of Co/MCM-41 nano-composites

    Energy Technology Data Exchange (ETDEWEB)

    Cuello, N. [CITeQ-Universidad Tecnológica Nacional-Facultad Regional Córdoba, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba (Argentina); Elías, V. [CITeQ-Universidad Tecnológica Nacional-Facultad Regional Córdoba, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba (Argentina); CONICET (Argentina); Crivello, M. [CITeQ-Universidad Tecnológica Nacional-Facultad Regional Córdoba, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba (Argentina); Oliva, M. [FaMAF-Universidad Nacional de Córdoba, Córdoba (Argentina); IFEG-CONICET (Argentina); Eimer, G., E-mail: geimer@scdt.frc.utn.edu.ar [CITeQ-Universidad Tecnológica Nacional-Facultad Regional Córdoba, Maestro López esq. Cruz Roja Argentina, 5016 Córdoba (Argentina); CONICET (Argentina)

    2013-09-15

    Synthesis, structure and magnetic properties of Co/MCM-41 as magnetic nano-composites have been investigated. Mesoporous materials with different degrees of metal loading were prepared by wet impregnation and characterized by ICP, XRD, N{sub 2} adsorption, UV–vis DRS, TPR and EPMA-EDS. Cobalt oxide clusters and Co{sub 3}O{sub 4} nano-particles could be confined inside the mesopores of MCM-41, being this fact favored by the Co loading increasing. In addition, larger crystals of Co{sub 3}O{sub 4} detectable by XRD also grow on the surface when the Co loading is enhanced. The magnetic characterization was performed in a SQUID magnetometer using a maximum magnetic applied field µ{sub 0}Ha=1 T. While the samples with the higher Co loadings showed a behavior typically paramagnetic, a superparamagnetic contribution is more notorious for lower loadings, suggesting high Co species dispersion. - Graphical abstract: Room temperature hysteresis loops as a function of the Co content. Display Omitted - Highlights: • Co species as isolated Co{sup 2+}, oxide clusters and Co{sub 3}O{sub 4} nano-particles were detected. • For higher Co loads were detected, by XRD, Co{sub 3}O{sub 4} particles on the external surface. • The confining of Co species inside the mesopores was achieved by increasing Co load. • Paramagnetism from oxide clusters/nano-particles becomes dominant for higher Co loads. • Superparamagnetism can be assigned to Co species of small size and finely dispersed.

  11. Magnetic, structural, and Raman characterization of RBa2Cu2NbO8(R=Pr, La, or Nd)

    International Nuclear Information System (INIS)

    PrBa2Cu2NbO8 (PrBCNO) is an insulator analogous to the PrBa2Cu3O7 system having a similar structure but with NbO2 planes replacing the CuO chains. Single-phase polycrystalline samples of RBCNO have been synthesized with R=La, Pr, or Nd. These materials were characterized using magnetization, thermal gravimetric analysis in different atmospheres, x-ray diffraction, and Raman spectroscopy. The PrBCNO samples show a signature in the magnetization of a magnetic ordering at 12 K. No such magnetic phase transition is observed down to 2 K in NdBa2Cu2NbO8

  12. Development of soft magnetic materials with special properties

    International Nuclear Information System (INIS)

    New steps in the development of soft magnetic alloys are based on a better understanding of the magnetizing processes in close connection with the development of magnetic forms and components for different applications. New result on the influence of crystal grains, inclusions, and mechanical stresses on the soft magnetic properties of Ni-Fe-alloys with ca. 50 to 75% Nickel-contents are given. Special soft magnetic alloys were developed and improved for low temperature applications, for small temperature coefficients, for different shapes of hysteresis loops, or for high wear resistance - and moreover forms, components, and basic designs of chokes for RFI suppression, of transformers for electronic power supplies, of transformers for ground-fault interrupters, and for magnetic shielding equipments. (orig.) 891 GSC/orig. 892 AV

  13. Experimental investigation of ion-implanted magnetic recording material

    International Nuclear Information System (INIS)

    The structure changes in ion implanted Permalloy have been observed by reflection high energy electron diffraction and X-ray photoelectron spectrometry. Amorphous phase and metal compound are formed in the surface layer. The magnetic property, mechanical property and surface roughness of the ion implanted samples and frequency response of the ion implanted magnetic head have been measured. The experimental results show that the hardening layer could be formed on the surface of an implanted sample without any degradation of the magnetic property

  14. NDE for Material Characterization in Aeronautic and Space Applications

    Science.gov (United States)

    Baaklini, George Y.; Kautz, Harold E.; Gyekenyesi, Andrew L.; Abdul-Aziz, Ali; Martin, Richard E.

    2000-01-01

    This paper describes selected nondestructive evaluation (NDE) approaches that were developed or tailored at the NASA Glenn Research Center for characterizing advanced material systems. The emphasis is on high-temperature aerospace propulsion applications. The material systems include monolithic ceramics, superalloys, and high temperature composites. In the aeronautic area, the highlights are cooled ceramic plate structures for turbine applications, F-TiAl blade materials for low-pressure turbines, thermoelastic stress analysis (TSA) for residual stress measurements in titanium based and nickel based engine materials, and acousto ultrasonics (AU) for creep damage assessment in nickel-based alloys. In the space area, examples consist of cooled carbon-carbon composites for gas generator combustors and flywheel rotors composed of carbon fiber reinforced polymer matrix composites for energy storage on the international space station (ISS). The role of NDE in solving manufacturing problems, the effect of defects on structural behavior, and the use of NDE-based finite element modeling are discussed. NDE technology needs for improved microelectronic and mechanical systems as well as health monitoring of micro-materials and components are briefly discussed.

  15. Preparation of Dysprosium Ferrite/Polyacrylamide Magnetic Composite Microsphere and Its Characterization

    Institute of Scientific and Technical Information of China (English)

    Hidehiro Kumazawa; Wang Zhifeng; Zhou Lanxiang; Zhang Hong; Li Yourong; Zhang Ming

    2005-01-01

    Using the technique of microemulsion polymerization with nano-reactor, dysprosium ferrite/polyacrylamide magnetic composite microsphere was prepared by one-step method in a single inverse microemulsion. The structure, average particle size, morphology of composite microsphere were characterized by FTIR, XRD, TEM and TGA. The magnetic responsibility of composite microsphere was also investigated. The results indicate that the magnetic composite microsphere possess high magnetic responsibility and suspension stability.

  16. Experimental characterization of explosively generated aerosols from radiological material surrogates

    International Nuclear Information System (INIS)

    Full text: Radiological Dispersal Devices (RDDs) are of increasing interest in the media and therefore also with emergency planners and risk assessors. When assessing the potential risks associated with RDDs, a key question is the dispersibility of radioactive material under explosive loads. Canada has a project, funded under the CBRNE Research and Technology Initiative (CRTI), to fill gaps in our knowledge of explosive dispersal of radiological material. This project quantifies both the amount and the physical form of the aerosol generated in such an event and uses these properties to predict the potential biological effects of explosively dispersed radioactive material. Characterization of explosively generated aerosols, using non-radioactive simulant for radiological material is taking place at Defence R and D Canada - Valcartier. DRDC Valcartier has an extensive explosives test range and is capable of performing these experiments in both closed and open environments. Indoor testing began in September 2005, with approximately 25 of these tests performed to date. These indoor tests were used to determine both the amount and the particle size distribution of the explosively generated aerosols. To complement the source term data determined from the indoor tests, a series of outdoor explosive trials began in October 2005. These outdoor tests used benign tracer materials, characterized in indoor explosive testing, to simulate release in real atmospheric conditions. The generated plume was tracked using a LIDAR system and these measurements of the plume evolution were used to develop a short-distance-scale dispersion model using a neural network. Results of the indoor and outdoor explosive tests are presented, along with health physics risk assessments based upon measured parameters and simulations.

  17. Characterization of cement-based ancient building materials in support of repository seal materials studies

    International Nuclear Information System (INIS)

    Ancient mortars and plasters collected from Greek and Cypriot structures dating to about 5500 BC have been investigated because of their remarkable durability. The characteristics and performance of these and other ancient cementitious materials have been considered in the light of providing information on longevity of concrete materials for sealing nuclear waste geological repositories. The matrices of these composite materials have been characterized and classified into four categories: (1) gypsum cements; (2) hydraulic hydrated lime and hydrated-lime cements; (3) hydraulic aluminous and ferruginous hydrated-lime cements (+- siliceous components); and (4) pozzolana/hydrated-lime cements. Most of the materials investigated, including linings of ore-washing basins and cisterns used to hold water, are in categories (2) and (3). The aggregates used included carbonates, sandstones, shales, schists, volcanic and pyroclastic rocks, and ore minerals, many of which represent host rock types of stratigraphic components of a salt repository. Numerous methods were used to characterize the materials chemically, mineralogically, and microstructurally and to elucidate aspects of both the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical (mineralogical) and microstructural factors. Durability was found to be affected by matrix mineralogy, particle size and porosity, and aggregate type, grading, and proportioning, as well as method of placement and exposure conditions. Similar factors govern the potential for durability of modern portland cement-containing materials, which are candidates for repository sealing. 29 references, 29 figures, 6 tables

  18. Fabrication and characterization of modified-hydroxyapatite/polyetheretherketone coating materials

    Science.gov (United States)

    Ma, Rui; Fang, Lin; Luo, Zhongkuan; Zheng, Ruisheng; Song, Shenhua; Weng, Luqian; Lei, JinPing

    2014-09-01

    45 wt%-Hydroxyaptite/polyetheretherketone (HA/PEEK) coating materials modified by silane coupling agent (KH560) on PEEK substrate were successfully fabricated by solution casting method and characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and tensile testing. The modified HA fillers were obtained to be uniformly distributed in the HA/PEEK coating, which has better properties of tensile strength and fracture toughness than those of the unmodified specimen. A good bonding between the composite coating and the PEEK substrate was achieved by solution casting method, resulting in integral-fracture without falling apart or delaminating during tensile loading. The modified specimens dipped into simulated body fluid (SBF) were characterized by SEM, XRD and FTIR, indicating that the bioactivity of the dipped materials was demonstrated more apparent with extending the dipping time. Therefore, the coating materials may become the substitutes for the hard tissues of the human body in the future, which could realize the balance between the mechanical properties and the bioactivity by modifying the structural design of the coating.

  19. Material characterization of a novel new armour steel

    Directory of Open Access Journals (Sweden)

    Stumpf W.E.

    2012-08-01

    Full Text Available The material characterization of a novel new armour steel with comparison to a leading commercial benchmark alloy is presented. Direct ballistic and experimental comparison is drawn. The 5.56 × 45 mm [M193] and 7.62 × 51 mm [NATO Ball] projectiles were used in a cartridge type high pressure barrel configuration to evaluate the superior plugging resistance of the new steel over a range of plate thicknesses. To characterize the dynamic plasticity of the materials, quasi-static, notched and high temperature tensile tests as well as Split Hopkinson Pressure Bar tests in tension and compression were performed. The open source explicit solver, IMPACT (sourceforge.net is used in an ongoing numerical and sensitivity analysis of ballistic impact. A simultaneous multi variable fitting algorithm is planned to evaluate several selected numerical material models and show their relative correlation to experimental data. This study as well as micro-metallurgical investigation of adiabatic shear bands and localized deformation zones should result in new insights in to the underlying metallurgical and physical behavior of armour plate steels during ballistic perforation.

  20. Multi-segmented Magnetic Nanowires Fabrication and Characterization

    KAUST Repository

    Moreno Garcia, Julian

    2016-04-28

    In this work, nickel-gold multi-segmented magnetic nanowires were grown by electrodeposition in anodized alumina templates. The templates were fabricated by a two step anodization process of aluminum disks in an aqueous solution of oxalic acid. In this process, ordered pores grew in an alumina oxide layer at the exposed aluminum area. Each disk was electropolished before the anodization process and the features at its surface were characterized to assess the effect on the pore ordering. Nickel Watts and gold cyanide electrolyte baths were prepared to electrodeposit pure nickel and gold in the templates. Both solutions response to a range of externally applied voltages was characterized and a threshold voltage above which deposition occurs is reported. Single nanowires were isolated by chemically dissolving the template and dispersed in ethanol. Devices were fabricated with these isolated nanowires in which gold contacts were deposited to measure the resistance. A current pulse setup was implemented in a magnetoresistance system allowing to send current pulses with amplitude as low as 2nA and 50μs width. Magneto resistance measurement were carried out on the single nanowires devices and the effect of current pulses was studied. It was found that distinct resistance states can be achieved by applying a determined current pulse at a constant applied field and that the initial state can be recovered by removing excess charge from the nanowire. Finally, the effect of annealing the nanowires in an air atmosphere at 150°C for 24 hours is studied showing that the nickel sections oxidize and the gold sections remain unchanged.

  1. Electrical, thermal, catalytic and magnetic properties of nano-structured materials and their applications

    Science.gov (United States)

    Liu, Zuwei

    Nanotechnology is a subject that studies the fabrication, properties, and applications of materials on the nanometer-scale. Top-down and bottom-up approaches are commonly used in nano-structure fabrication. The top-down approach is used to fabricate nano-structures from bulk materials by lithography, etching, and polishing etc. It is commonly used in mechanical, electronic, and photonic devices. Bottom-up approaches fabricate nano-structures from atoms or molecules by chemical synthesis, self-assembly, and deposition, such as sol-gel processing, molecular beam epitaxy (MBE), focused ion beam (FIB) milling/deposition, chemical vapor deposition (CVD), and electro-deposition etc. Nano-structures can have several different dimensionalities, including zero-dimensional nano-structures, such as fullerenes, nano-particles, quantum dots, nano-sized clusters; one-dimensional nano-structures, such as carbon nanotubes, metallic and semiconducting nanowires; two-dimensional nano-structures, such as graphene, super lattice, thin films; and three-dimensional nano-structures, such as photonic structures, anodic aluminum oxide, and molecular sieves. These nano-structured materials exhibit unique electrical, thermal, optical, mechanical, chemical, and magnetic properties in the quantum mechanical regime. Various techniques can be used to study these properties, such as scanning probe microscopy (SPM), scanning/transmission electron microscopy (SEM/TEM), micro Raman spectroscopy, etc. These unique properties have important applications in modern technologies, such as random access memories, display, solar energy conversion, chemical sensing, and bio-medical devices. This thesis includes four main topics in the broad area of nanoscience: magnetic properties of ferro-magnetic cobalt nanowires, plasmonic properties of metallic nano-particles, photocatalytic properties of titanium dioxide nanotubes, and electro-thermal-optical properties of carbon nanotubes. These materials and their

  2. Separator Materials Used in Secondary Alkaline Batteries Characterized and Evaluated

    Science.gov (United States)

    1996-01-01

    Nickel-cadmium (Ni/Cd) and nickel-hydrogen (Ni/H2) secondary alkaline batteries are vital to aerospace applications. Battery performance and cycle life are significantly affected by the type of separators used in those batteries. A team from NASA Lewis Research Center's Electrochemical Technology Branch developed standardized testing procedures to characterize and evaluate new and existing separator materials to improve performance and cycle life of secondary alkaline batteries. Battery separators must function as good electronic insulators and as efficient electrolyte reservoirs. At present, new types of organic and inorganic separator materials are being developed for Ni/Cd and Ni/H2 batteries. The separator material previously used in the NASA standard Ni/Cd was Pellon 2505, a 100-percent nylon-6 polymer that must be treated with zinc chloride (ZnCl2) to bond the fibers. Because of stricter Environmental Protection Agency regulation of ZnCl2 emissions, the battery community has been searching for new separators to replace Pellon 2505. As of today, two candidate separator materials have been identified; however, neither of the two materials have performed as well as Pellon 2505. The separator test procedures that were devised at Lewis are being implemented to expedite the search for new battery separators. The new test procedures, which are being carried out in the Separator Laboratory at Lewis, have been designed to guarantee accurate evaluations of the properties that are critical for sustaining proper battery operation. These properties include physical and chemical stability, chemical purity, gas permeability, electrolyte retention and distribution, uniformity, porosity, and area resistivity. A manual containing a detailed description of 12 separator test procedures has been drafted and will be used by the battery community to evaluate candidate separator materials for specific applications. These standardized procedures will allow for consistent, uniform

  3. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    OpenAIRE

    Marchevsky, M.; Wang, X.; Sabbi, G.; Prestemon, S.

    2014-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [...

  4. Nondestructive characterization of ductile cast iron by magnetic adaptive testing

    Czech Academy of Sciences Publication Activity Database

    Vértesy, G.; Uchimoto, T.; Tomáš, Ivan; Takagi, T.

    2010-01-01

    Roč. 322, č. 20 (2010), s. 3117-3121. ISSN 0304-8853 R&D Projects: GA ČR GA101/09/1323; GA AV ČR 1QS100100508 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic NDE * magnetic adaptive testing * magnetic hysteresis * cast iron Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.689, year: 2010

  5. Characterization of composite particles responsive to electric and magnetic fields

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiaopeng; GUO Hongxia

    2004-01-01

    The multilayer particles with responses to electric and magnetic fields are a prerequisite for particles assembled under external fields. Three routes to produce particles responsive to electric and magnetic fields are presented in this article. The size and morphology, properties as well as the electric-magnetic responses of three kinds of particles are comparatively discussed. This will provide a useful basis for the control of the behavior of the particles in suspensions by external electric and magnetic fields.

  6. Synthesis and Characterization of Surface-Functionalized Magnetic Polylactide Nanospheres

    OpenAIRE

    Ragheb, Ragy Tadros

    2008-01-01

    Polylactide homopolymers with pendent carboxylic acid functional groups have been designed and synthesized to be studied as magnetite nanoparticle dispersion stabilizers. Magnetic nanoparticles are of interest for a variety of biomedical applications including magnetic field-directed drug delivery and magnetic cell separations. Small magnetite nanoparticles are desirable due to their established biocompatibility and superparamagnetic (lack of magnetic hysteresis) behavior. For in-vivo applic...

  7. Design of an ellipsoidal mirror for freewave characterization of materials at microwave frequencies

    Science.gov (United States)

    Rojo, M.; Muñoz, J.; Molina-Cuberos, G. J.; García-Collado, Á. J.; Margineda, J.

    2016-03-01

    Free-wave characterization of the electromagnetic properties of materials at microwave frequencies requires that scattering at the edges of the samples and/or holder be minimized. Here, an ellipsoidal mirror is designed and characterized in order to decrease the size of the beam, thereby avoiding the scattering problems, even when relatively small samples are used. In the experimental configuration, both the emitting antenna and sample are located at the mirror focuses. Since both the emitted and reflected (focused) beams are Gaussian in nature, we make use of Gaussian beam theory to carry out the design. The mirror parameters are optimized by numerical simulations (COMSOL Multiphysics®) and then experimentally tested. An experimental setup is presented for dielectric, magnetic and chiral measurement in the 4.5-18 GHz band.

  8. Raman spectroscopy characterization of colored pigments in archaeological materials

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    archaeological scientists are now much aware of the importance of physicochemical characterization for the attribution of the historical period and genuineness of an item. Ancient technological methods used in the construction of the items may be characterized by spectroscopists with a minimal disturbance to the....... The use of Raman spectroscopy can be taken to illustrate this: It provides e.g. information of importance to art restorers and museum conservation scientists in preserving materials and the understanding of deterioration processes. It does so by identification of key components, as shown in Fig. 1...... review. The number of research papers on the subject of Raman spectroscopy applied to pigments and art has been growing very fast during the last years. To get a comprehensive overview we refer to three recent theme numbers of Journal of Raman Spectroscopy1, 2, 3 and other dedicated texts such as e...

  9. Characterization of nanostructured material images using fractal descriptors

    CERN Document Server

    Florindo, João B; Pereira, Ernesto C; Bruno, Odemir M

    2012-01-01

    This work presents a methodology to the morphology analysis and characterization of nanostructured material images acquired from FEG-SEM (Field Emission Gun-Scanning Electron Microscopy) technique. The metrics were extracted from the image texture (mathematical surface) by the volumetric fractal descriptors, a methodology based on the Bouligand-Minkowski fractal dimension, which considers the properties of the Minkowski dilation of the surface points. An experiment with galvanostatic anodic titanium oxide samples prepared in oxalyc acid solution using different conditions of applied current, oxalyc acid concentration and solution temperature was performed. The results demonstrate that the approach is capable of characterizing complex morphology characteristics such as those present in the anodic titanium oxide.

  10. Characterization of piezoelectric material for micro thermal harvesters

    International Nuclear Information System (INIS)

    This paper presents the first realizations of a novel concept for thermal energy harvesting at micro scale. The devices proposed here are based on a two-step transduction combining thermo-mechanical and piezoelectric conversion. In this contribution, we present for the first time results on micro fabricated structures with integrated piezoelectric layers, focusing mainly on the characterization of the piezoelectric material. The process flow to get a bilayered bistable structure is briefly described, highlighting the way how to control the initial deflection. The characterization of the piezoelectric thin film is presented then. The e31,f coefficient is measured in both sensor and actuator mode and is found to be equal to -0,91 C.m−2 in both configurations. This value, close to the state-of-the-art, is very promising for the future thermal harvesting applications. Finally the buckling of a structure actuated by a voltage was observed and the corresponding displacement measured by laser interferometry

  11. Microscale mechanical characterization of materials for extreme environments

    Science.gov (United States)

    Ozerinc, Sezer

    Nanocrystalline metals are promising materials for applications that require outstanding strength and stability in extreme environments. Further improvements in the desirable mechanical properties of these materials require a better understanding of the relationship between their microstructure and grain boundary deformation behavior. Previous molecular dynamics simulations suggested that solute additions to grain boundaries can enhance the strength of nanocrystalline metals, but there has been a lack of experimental studies investigating this prediction. This dissertation presents mechanical and microstructural characterization of nanocrystalline Cu alloys and demonstrate that addition of Nb solutes to grain boundaries greatly enhances the strength of Cu. The measured hardness of Cu90Nb10 alloy is 5.6 GPa which is more than double the hardness of nanocrystalline pure Cu. Microstructural characterization through transmission electron microscopy and energy-dispersive X-ray spectroscopy on these alloys indicates a strong correlation between the grain boundary composition and the hardness. Variation of measured hardness with measured grain boundary composition is in very good agreement with previous molecular dynamics simulation predictions. The results of this work provide experimental evidence that grain boundary doping enhances the strength of nanocrystalline Cu far beyond that predicted by classical Hall-Petch strengthening and decreasing grain boundary energy through solute additions is the key to reaching theoretical strength in nanocrystalline metals. Irradiation induced creep is a deformation mechanism that takes place under combined stress and particle bombardment. Effective characterization of this phenomenon on nanostructured materials is crucial for the assessment of their potential use in next generation nuclear power plants. Direct measurements of irradiation induced creep under MeV-heavy ion bombardment have not been feasible until recently due to the

  12. Correlation of nanoscale structure with electronic and magnetic properties in semiconductor materials

    Science.gov (United States)

    He, Li

    The goal of this research is to correlate individual nanostructures with their electronic and magnetic properties. Three classes of semiconductor materials and nanostructures were investigated: nanowires, dilute magnetic semiconductors, and quantum dots. First, we fabricated electrical contact to free-standing nanowires using focused ion beam (FIB)-induced deposition and achieved ohmic contact between GaP nanowires and FIB-deposited Pt. Ion irradiation was found to change the nanowire resistance, presumably through the generation of electrical active defects. Based on the finding that ion beam induces deposition outside the direct impact area, a new fabrication method for nanowire core-shell structures was developed by creating an annular direct deposition pattern around the nanowire. We also developed a new nanowire transmission electron microscopy (TEM) sample preparation method that enabled the free-standing nanowires to be individually studied in the TEM. Distribution of Pt and Si elements in the deposited layers was confirmed by x-ray energy dispersive spectroscopy and electron energy filtered imaging (elemental mapping). The indirect deposition mechanism is attributed to the interaction of secondary electrons generated from the primary ion impact area with the deposition precursor absorbed at the nanowire surface. The calculated secondary electron flux distribution matched well with the variation of deposition thickness along the nanowire length and with the pattern radius. The second part of this work employed Mn implantation in Ge with subsequent rapid thermal annealing or TEM in-situ annealing to study the correlation between structure and magnetic properties in Ge:Mn magnetic semiconductor materials. Implantation at 75°C with dual Mn doses (2.4x10 15/cm2 at 170 keV, followed by 5.6x10 15/cm2 at 60 keV) produced an amorphous Ge film containing Mn-rich clusters. Its magnetic properties indicated dispersion of ferromagnetic regions in a non-magnetic matrix

  13. Magnetic characterization of HSLA steel by power-law decay exponents of Barkhausen emission signal

    Energy Technology Data Exchange (ETDEWEB)

    Tarafder, M. [National Metallurgical Laboratory, Mathematical Modelling and Simulation Division, Jamshedpur 831 007 (India)], E-mail: mt@nmlindia.org; Chattoraj, I. [National Metallurgical Laboratory, Mathematical Modelling and Simulation Division, Jamshedpur 831 007 (India); Nasipuri, M. [Jadavpur University, Kolkata 700032 (India); Mitra, A. [National Metallurgical Laboratory, Mathematical Modelling and Simulation Division, Jamshedpur 831 007 (India)

    2009-04-15

    The general trend of magnetic behaviour of materials is that the mechanically hard materials are also magnetically hard. However for the high strength low alloy (HSLA) steel tempered at various aging temperatures, the correlation was reported as negative. The anomaly could not be explained by the magnetic parameters like RMS voltage calculated from the Barkhausen emission signal and the coercivity from the magnetic hysteresis loop. This paper reports another magnetic parameter known as power-law decay exponent which shows excellent correlation with the mechanical properties and thus explains the progressive evolution of the microstructural constituents in HSLA steel.

  14. Magnetic characterization of HSLA steel by power-law decay exponents of Barkhausen emission signal

    Science.gov (United States)

    Tarafder, M.; Chattoraj, I.; Nasipuri, M.; Mitra, A.

    2009-04-01

    The general trend of magnetic behaviour of materials is that the mechanically hard materials are also magnetically hard. However for the high strength low alloy (HSLA) steel tempered at various aging temperatures, the correlation was reported as negative. The anomaly could not be explained by the magnetic parameters like RMS voltage calculated from the Barkhausen emission signal and the coercivity from the magnetic hysteresis loop. This paper reports another magnetic parameter known as power-law decay exponent which shows excellent correlation with the mechanical properties and thus explains the progressive evolution of the microstructural constituents in HSLA steel.

  15. Generation and characterization of microcracks in structural materials

    International Nuclear Information System (INIS)

    In this paper, we study how to generate and accelerate, expansive phenomena within cementitious composites, considering elements of addiction using both fly ash and slag. We present results of monitoring of these processes from the beginning and characterize chemical, microstructural, and crystallographic by X-ray diffraction, backscattering electron microscopy, X-ray dispersive energy and mercury porosimetry. These data are supplemented with values of mechanical behavior of materials to determine their functionality. As a result of these studies, we propose a model for the generation and progression of microcracks for each alteration processes studied. (Author) 7 refs.

  16. Quality manual for Laboratories of the Nuclear Materials Characterization Division

    International Nuclear Information System (INIS)

    This publication presents the first Quality Manual for the Laboratories at the Nuclear Materials Characterization Division. The Manual describes the laboratories, its organization structure, fields of activities, personnel records, equipments, maintenance and calibration. The main aspects concerning quality assurance in the analysis were discussed. The whole system of receiving, identifying and processing analysis of the samples is shown. Since there are many information to be contained in several subjects of the Quality Manual, there were produced separate documents that are cross referenced in the manual. (author)

  17. Synthesis and characterization of blue light emitting materials containing imidazole

    International Nuclear Information System (INIS)

    A series of novel imidazole derivatives as blue light emitting materials were synthesized by heck coupling reaction and characterized with respect to their chemical, luminescence and thermal properties. The results were shown that the imidazole derivatives were strongly blue fluorescent (λ = 455-487 nm) with high fluorescence quantum yields (Φf = 0.28-0.63). All of these compounds have excellent thermal properties (382-423 deg. C) due to the molecular structure introduced by imidazole heterocycles, and the imidazole derivatives (M1 and M2) can be polymerized as monomers

  18. Low-temperature magnetic modification of sensitive biological materials

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 142, mar (2015), s. 184-188. ISSN 0167-577X R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : magnetic iron oxides particles * microwave-assisted synthesis * low-temperature magnetic modification * immobilized enzymes Subject RIV: EH - Ecology, Behaviour Impact factor: 2.489, year: 2014

  19. Characterization of n-GaN dilute magnetic semiconductors by cobalt ions implantation at high-fluence

    International Nuclear Information System (INIS)

    In this study, we present the structural and magnetic characteristics of cobalt ions implantation at a high-fluence (5×1016 cm−2) into n-GaN epilayer of thickness about 1.6 μm. The n-GaN was grown on sapphire by metal organic chemical vapor deposition (MOCVD). Rutherford backscattering channeling was used for the structural study. After implantation, samples were annealed at 700, 800 and 900 °C by rapid thermal annealing in ambient N2. XRD measurements did not show any secondary phase or metal related-peaks. High resolution X-ray diffraction (HRXRD) was performed as well to characterize structures. Well-defined hysteresis loops were observed at 5 K and room temperature using alternating gradient magnetometer AGM and Superconducting Quantum Interference Device (SQUID) magnetometer. Temperature-dependent magnetization indicated magnetic moment at the lowest temperatures and retained magnetization up to 380 K for cobalt-ion-implanted samples. - Highlights: ► Experiment started with MOCVD grown semiconducting material GaN. ► GaN was implanted with cobalt ions (Co+) of dose 5×1016 cm−2 at room temperature. ► Structural characterization was performed by RBS, XRD and HR-XRD. ► Magnetic properties were observed by AGM and SQUID measurements. ► High TC dilute magnetic semiconductors has been observed up to 380 K for cobalt implanted GaN at high-fluence (5×1016 cm−2).

  20. Characterization of geological materials using ion and photon beams.

    CERN Document Server

    Torok, S B; Tuniz, C

    1998-01-01

    Geological specimens are often complex materials that require different analytical methods for their characterization. The parameters of interest may include the chemical composition of major, minor and trace elements. The chemical compounds incorporated in the minerals, the crystal structure and isotopic composition need to be considered. Specimens may be highly heterogeneous thus necessitating analytical methods capable of measurements on small sample volumes with high spatial resolution and sensitivity. Much essential information on geological materials can be obtained by using ion or photon beams. In this chapter we describe the principal analytical techniques based on particle accelerators, showing some applications that are hardly possible with conventional methods. In particular, the following techniques will be discussed: (1) Synchrotron radiation (SR) induced X-ray emission (SRIXE) and particle-induced X-ray emission (PEE) and other ion beam techniques for trace element analysis. (2) Accelerator mass...