The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
H S Chang - One of the best experts on this subject based on the ideXlab platform.
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magnetic properties of the Sendust ta2o5 multilayer thin films
Journal of Applied Physics, 1990Co-Authors: N T Park, S I Kwon, H S Song, H S ChangAbstract:The Sendust multilayer thin films were fabricated to improve magnetic properties by rf magnetron sputtering. The effective permeability of the film with 50 A of a Ta2O5 middle layer was 1800 when annealed at 500° C. The coercivity of the film was 0.5 Oe. When the middle‐layer thickness was thicker than 100 A, the result showed no magnetic improvement in permeability and coercivity.
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Magnetic properties of the Sendust/Ta2O5 multilayer thin films
Journal of Applied Physics, 1990Co-Authors: N T Park, S I Kwon, H S Song, H S ChangAbstract:The Sendust multilayer thin films were fabricated to improve magnetic properties by rf magnetron sputtering. The effective permeability of the film with 50 A of a Ta2O5 middle layer was 1800 when annealed at 500° C. The coercivity of the film was 0.5 Oe. When the middle‐layer thickness was thicker than 100 A, the result showed no magnetic improvement in permeability and coercivity.
Ling Bing Kong - One of the best experts on this subject based on the ideXlab platform.
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Dielectric and magnetic properties of NiCuZn ferrite coated Sendust flakes through a sol–gel approach
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Zhihong Yang, Zhaoliang Li, Yanhui Yang, Ling Bing KongAbstract:Abstract Sendust flakes (with 9.59% Si, 5.88% Al and balanced Fe) were coated with NiCuZn ferrite nanoparticles by using a simple sol–gel approach. Both the coated and uncoated flakes were characterized by using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Composites made from the Sendust flakes with the in-plane alignment were fabricated via a vacuum infiltration method. Microwave measurement results indicated that permittivity of the composite made of the coated Sendust flakes was remarkably reduced, with a slight decrease in permeability over 0.1–8.55 GHz. Consequently, the sample with a thickness of 6 mm showed reflection loss exceeding −20 dB at 1.4 GHz, while reflection loss of the composite derived from the uncoated Sendust flakes could not reach −10 dB at the same sample thickness. Therefore, the Sendust flakes coated with NiCuZn ferrite nanoparticles could be promising candidates to develop microwave attenuation materials.
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dielectric and magnetic properties of nicuzn ferrite coated Sendust flakes through a sol gel approach
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Zhaoliang Li, Zhihong Yang, Yanhui Yang, Ling Bing KongAbstract:Abstract Sendust flakes (with 9.59% Si, 5.88% Al and balanced Fe) were coated with NiCuZn ferrite nanoparticles by using a simple sol–gel approach. Both the coated and uncoated flakes were characterized by using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Composites made from the Sendust flakes with the in-plane alignment were fabricated via a vacuum infiltration method. Microwave measurement results indicated that permittivity of the composite made of the coated Sendust flakes was remarkably reduced, with a slight decrease in permeability over 0.1–8.55 GHz. Consequently, the sample with a thickness of 6 mm showed reflection loss exceeding −20 dB at 1.4 GHz, while reflection loss of the composite derived from the uncoated Sendust flakes could not reach −10 dB at the same sample thickness. Therefore, the Sendust flakes coated with NiCuZn ferrite nanoparticles could be promising candidates to develop microwave attenuation materials.
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high frequency properties of composite membrane with in plane aligned Sendust flake prepared by infiltration method
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Zhihong Yang, C R Deng, Zhaoliang Li, Madina A. Abshinova, Ling Bing KongAbstract:Abstract Composite membranes (with thickness around 100–200 μm) containing highly in-plane aligned Sendust flakes embedded in polyvinyl alcohol matrix were prepared with a novel infiltration method. As compared with tape-casting method, infiltration method results in enhanced magnetic permeability, which could be caused by better alignment and less porosity. Annealing process could modify the grain size, improve saturation magnetization and coercivity of Sendust flakes. Hence, the radio and quasi-microwave frequency permeability (between 10 MHz to 3 GHz) of composites membranes with annealed Sendust flakes could be enhanced significantly as compared with that of the as-prepared flakes. Infiltration method is especially suitable for composites with high concentration of flaky fillers. The composite membranes prepared have potential applications, including electromagnetic shielding, noise reduction and wave absorption.
Zhihong Yang - One of the best experts on this subject based on the ideXlab platform.
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Dielectric and magnetic properties of NiCuZn ferrite coated Sendust flakes through a sol–gel approach
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Zhihong Yang, Zhaoliang Li, Yanhui Yang, Ling Bing KongAbstract:Abstract Sendust flakes (with 9.59% Si, 5.88% Al and balanced Fe) were coated with NiCuZn ferrite nanoparticles by using a simple sol–gel approach. Both the coated and uncoated flakes were characterized by using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Composites made from the Sendust flakes with the in-plane alignment were fabricated via a vacuum infiltration method. Microwave measurement results indicated that permittivity of the composite made of the coated Sendust flakes was remarkably reduced, with a slight decrease in permeability over 0.1–8.55 GHz. Consequently, the sample with a thickness of 6 mm showed reflection loss exceeding −20 dB at 1.4 GHz, while reflection loss of the composite derived from the uncoated Sendust flakes could not reach −10 dB at the same sample thickness. Therefore, the Sendust flakes coated with NiCuZn ferrite nanoparticles could be promising candidates to develop microwave attenuation materials.
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dielectric and magnetic properties of nicuzn ferrite coated Sendust flakes through a sol gel approach
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Zhaoliang Li, Zhihong Yang, Yanhui Yang, Ling Bing KongAbstract:Abstract Sendust flakes (with 9.59% Si, 5.88% Al and balanced Fe) were coated with NiCuZn ferrite nanoparticles by using a simple sol–gel approach. Both the coated and uncoated flakes were characterized by using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Composites made from the Sendust flakes with the in-plane alignment were fabricated via a vacuum infiltration method. Microwave measurement results indicated that permittivity of the composite made of the coated Sendust flakes was remarkably reduced, with a slight decrease in permeability over 0.1–8.55 GHz. Consequently, the sample with a thickness of 6 mm showed reflection loss exceeding −20 dB at 1.4 GHz, while reflection loss of the composite derived from the uncoated Sendust flakes could not reach −10 dB at the same sample thickness. Therefore, the Sendust flakes coated with NiCuZn ferrite nanoparticles could be promising candidates to develop microwave attenuation materials.
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high frequency properties of composite membrane with in plane aligned Sendust flake prepared by infiltration method
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Zhihong Yang, C R Deng, Zhaoliang Li, Madina A. Abshinova, Ling Bing KongAbstract:Abstract Composite membranes (with thickness around 100–200 μm) containing highly in-plane aligned Sendust flakes embedded in polyvinyl alcohol matrix were prepared with a novel infiltration method. As compared with tape-casting method, infiltration method results in enhanced magnetic permeability, which could be caused by better alignment and less porosity. Annealing process could modify the grain size, improve saturation magnetization and coercivity of Sendust flakes. Hence, the radio and quasi-microwave frequency permeability (between 10 MHz to 3 GHz) of composites membranes with annealed Sendust flakes could be enhanced significantly as compared with that of the as-prepared flakes. Infiltration method is especially suitable for composites with high concentration of flaky fillers. The composite membranes prepared have potential applications, including electromagnetic shielding, noise reduction and wave absorption.
H S Gamble - One of the best experts on this subject based on the ideXlab platform.
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preparation of soft anisotropic Sendust films in the as deposited state
Journal of Applied Physics, 1999Co-Authors: P M Dodd, R Atkinson, I W Salter, M S Araghi, H S GambleAbstract:FeSiAlN films have been prepared by N2 reactive deposition from a Sendust target by rf magnetron sputtering. Films show excellent magnetic properties in the as-deposited state with well-defined in-plane uniaxial anisotropy, which is highly desirable from a device perspective. Coercivity values of less than 0.5 Oe along the hard-axis direction were measured in 200 nm thick films. Magnetic properties were found to vary with nitrogen and argon flow rate ratio with optimum magnetic properties being produced using 0.2%–1.0% N2 in the sputter gas. Films sputtered in pure Ar showed high coercivity and grains appear to cluster together. The nitrided films by comparison had a drastically reduced coercivity, smaller grain size, and no grain clustering was present. Coercivity was found to increase with film thickness and anisotropy was less pronounced in films thicker than 500 nm. Cross-sectional transmission electron microscopy of thick Sendust films showed a clear change in growth morphology with a columnar micros...
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correlation between crystalline structure and soft magnetic properties in sputtered Sendust films
Journal of Applied Physics, 1997Co-Authors: P M Dodd, R Atkinson, M S Araghi, P Papakonstantinou, H S GambleAbstract:We have investigated the change in crystallographic and magnetic properties of Sendust thin films before/after annealing. Films were deposited by both rf diode and rf magnetron sputtering. rf diode-sputtered films did not possess soft magnetic properties in the as-deposited state. Films were subsequently annealed in both a conventional oven and a rapid thermal annealing (RTA) system. The coercivity of the films decreased from over 10 Oe to a minimum value of 0.6 Oe after annealing and a systematic shift in the (110) x-ray diffraction (XRD) peak position towards that of bulk Sendust was observed. No additional XRD peaks were observed after annealing. The optimum annealing conditions to minimize coercivity was found to be 1–2 h at 550 °C. By comparison, films processed by RTA resulted in minimum coercivity of 0.9 Oe obtained after annealing for 2 min at 550 °C. XRD for films annealed by both RTA and oven annealing showed a similar decrease in the d spacing of the (110) plane, indicating a release of tensile...
Xian Wang - One of the best experts on this subject based on the ideXlab platform.
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comparison of the magnetic and absorption properties of flaky super Sendust and Sendust alloys
Journal of Electronic Materials, 2015Co-Authors: Qifan Li, Ze Kun Feng, Xian WangAbstract:Super Sendust and Sendust alloy powders were ball-milled for the same time to produce flakes and their static and dynamic magnetic properties were determined. The average size of flaky Super Sendust alloy particles was approximately 45.25 μm; the average size of Sendust alloy flakes was 40 μm. Fe–Si–Al–Ni flaky particle composites have better electromagnetic properties than Fe–Si–Al flaky particles; they have lower complex permittivity and a permeability that is approximately 1.5 times the permeability of Fe–Si–Al composites. Fe–Si–Al–Ni particles also have higher resonance than Fe–Si–Al composites, which contributes to a wider applied frequency band. The calculated reflection loss shows that the microwave-absorption performance of Fe–Si–Al–Ni composites exceeds that of Fe–Si–Al. In addition, the Fe–Si–Al–Ni composite’s absorbing band of the reflection loss below −5 dB can cover both the L-band and S-band for an absorber thickness of 2.3 mm; this is three times as wide as that of the Fe–Si–Al composite.
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low loss Sendust powder cores comprised of particles coated by sodium salt insulating layer
Journal of Applied Physics, 2015Co-Authors: Xian Wang, Ze Kun Feng, Rongzhou Gong, Yajie Chen, V G HarrisAbstract:Toroid-shaped Sendust powder cores were prepared from cold pressing mechanically pulverized Fe-Si-Al powder that had been coated using an inorganic insulating layer. The present work focuses on the effect of the sodium salt-coated Sendust particles upon the high frequency magnetic properties. Sendust powders, having a particle size range of ∼125 μm, exhibit a high saturation magnetization of 118.9 A·m2/kg and a low coercivity of 56 A/m. The experiments indicate that the sodium-based glass insulating layer synthesized from sodium metaphosphate and sodium metaborate can effectively reduce the change in permeability with frequency or DC bias field, yielding high effective permeability (μe) of ∼113 over a wide frequency range from 10 kHz–1 MHz. Furthermore, the effective permeability is measured at ∼27 at H = 7854 A/m, indicating stable and high effective permeability under a DC bias field. The measurements of permeability under DC bias field indicate a peak in the quality factor (Q) values corresponding to a...
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effect of annealing temperature on the soft magnetic behavior of Sendust powder core
Applied Mechanics and Materials, 2014Co-Authors: Xian Wang, Ze Kun Feng, Rongzhou GongAbstract:The variation of soft magnetic properties of Sendust powder cores as a function of annealing temperature has been investigated. Toroid-shaped Sendust powder cores were prepared from Fe-Si-Al powder by machine pulverizing and subsequent cold pressing using inorganic insulating layer and organic binders, respectively. The influence of different compaction pressures and various annealing temperature on effective permeability and quality factor was investigated. Sendust powder cores using inorganic salt as insulating layer exhibit high effective permeability ( μe>110) up to 1 MHz, showing excellent frequency stable characteristics and high quality factor (Q>80) at 50 kHz. The optimized annealing temperature is 953K.
