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Full-Text Articles in Engineering
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Vincent G. Harris
The evolution of magnetic properties and local atomic ordering during thermal annealing has been studied for amorphous Fe₇₅Ni5B₁₅Si₅ thin films. Resistivity, vibrating sample magnetometer (VSM), ferromagnetic resonance (FMR), extended x-ray absorption fine structure (EXAFS), and Mossbauer effect (ME) measurements were taken on samples annealed at various temperatures ranging to film crystallization. The as-deposited samples are in a close-packed structure with little short-range order. Samples annealed above 200°C show ordering of the boron shell, but no indication of long-range ordering. With the exception of the anisotropy and coercive fields, no change in the magnetic or microwave magnetic parameters is observed for …
Screen Printed Thick Self-Biased, Low-Loss, Barium Hexaferrite Films By Hot-Press Sintering, Yajie Chen, Tomokazu Sakai, Taiyang Chen, Soack Yoon, Carmine Vittoria, Vincent Harris
Screen Printed Thick Self-Biased, Low-Loss, Barium Hexaferrite Films By Hot-Press Sintering, Yajie Chen, Tomokazu Sakai, Taiyang Chen, Soack Yoon, Carmine Vittoria, Vincent Harris
Vincent G. Harris
BaFe₁₂O₁₉ hexaferrite thick films having high hysteresis loop squareness (Mr/Ms) and low ferromagnetic resonance (FMR) linewidths were processed through the use of a screen printing technique coupled with hot-press sintering. Scanning electron microscopy and x-ray diffraction measurements exhibit strong crystallographic c-axis alignment of crystals perpendicular to the film plane. Static magnetic resonance and FMR measurements were performed to determine the effect of the preparation technique on magnetic hysteresis and microwave properties. Hot pressing during sintering produced dense thick films having high squareness (> 0.95) and reduced coercivity (∽1900 Oe). Of greater importance was the measurement of a minimum peak-to-peak FMR …
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Vincent G. Harris
CoFe/PtMn/CoFe films were deposited on seed layers of Ru or NiFeCr with CoFe film compositions being either Co-10 at. %Fe or Co-16 at. %Fe. Eight periods of the CoFe/PtMn/CoFe trilayers were also prepared. The magnetic properties and ferromagnetic resonance (FMR) of these films were characterized with vibrating-sample magnetometer, and field-sweep FMR system at X band (∽9.5 GHz). The Ru-seeded CoFe/PtMn/CoFe sandwich films show excellent magnetic softness with a low hard axis coercivity of 2-4 Oe, an easy axis Mr/Ms of >98%, and a significantly enhanced in-plane anisotropy of 57-123 Oe when CoFe layer thickness is above 200 Å. Contrary to …
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Vincent G. Harris
The interest in barium hexaferrite thick films, particularly with high remanent magnetization, is driven by the development of small planar ferrite microwave devices. We report here processing and microwave characterization of BaFe₁₂O₁₉ ferrite thick films (100-400 μm). The films were deposited on silicon and alumina substrates by screen printing, oriented under a magnetic field of 8 kOe, then annealed at 250°C and sintered at temperatures ranging from 850 to 1300°C. Scanning electron microscopy and x-ray diffraction exhibited strong crystallographic alignment of c-axis crystals perpendicular to the film plane. The magnetization measurement indicated that a typical dense film with 270 μm …
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Vincent G. Harris
We report on a new technique for the determination of the linear magnetostriction constant of thin films. The technique uses the shift in ferromagnetic resonance (FMR) of a magnetostrcitive sample upon application of an external stress. A circular thin film is deposited onto a fused quartz place by ion beam sputter deposition. The place is mounted in a cantilever configuration, with the film suspended over the junction of a slot-line/coplanar guided structure. The slot line proved a rf magnetic field normal to the film place, tunable over the frequency range 0.1 GHz