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Oriented Barium Hexaferrite Thick Films With Narrow Ferromagnetic Resonance Linewidth, Y. J. Chen, T. Sakai, T. Y. Chen, S. D. Yoon, A. L. Geiler, C. Vittoria, V. G. Harris
Oriented Barium Hexaferrite Thick Films With Narrow Ferromagnetic Resonance Linewidth, Y. J. Chen, T. Sakai, T. Y. Chen, S. D. Yoon, A. L. Geiler, C. Vittoria, V. G. Harris
Vincent G. Harris
Hexagonal BaFe₁₂O₁₉ ferrite films, having thicknesses ranging from 200-500μm, were prepared by a screen printing process followed by sintering heat treatments. Structural, magnetic, and microwave measurements confirmed that the polycrystalline films were suitable for applications in self-biasing microwave devices in that they exhibited a large remanence (4πMr=3800 G), high hysteresis loop squareness (Mr/Ms=0.96) and low microwave loss. A derivative linewidth ΔH of 310 Oe was measured at 55.6 GHz. This represents the lowest ΔH measured in polycrystalline hexaferrite materials. ΔH can be further improved by reducing porosity and improving the c-axis orientation of grains in polycrystalline ferrite.
Alternating Target Laser Ablation Deposition Of High Quality Barium Hexaferrite Thin Films From Barium Monoferrite And Hematite Targets, A. L. Geiler, S. D. Yoon, Y. Chen, A. Yang, C. N. Chinnasamy, M. Geiler, V. G. Harris, C. Vittoria
Alternating Target Laser Ablation Deposition Of High Quality Barium Hexaferrite Thin Films From Barium Monoferrite And Hematite Targets, A. L. Geiler, S. D. Yoon, Y. Chen, A. Yang, C. N. Chinnasamy, M. Geiler, V. G. Harris, C. Vittoria
Vincent G. Harris
An optimized alternating target laser ablation deposition (ATLAD) technique has been developed to grow high quality barium hexaferrite (BaFe₁₂O₁₉) thin films on basal plane oriented sapphire(Al₂O₃) substrates from barium monoferrite (BaFe₂O₄) and hematite (α-Fe₂O₃) targets. Crystallographic and structural characterization results show that the films possess low c-axis dispersion of Δ ω=0.259 degrees and hexagonal terraced surface morphology. Saturation magnetization and uniaxial magnetic anisotropy field were determined to be consistent with reference data on high quality barium hexaferrite films and bulk single crystals grown by other techniques. Ferromagnetic resonance linewidth of 42 Oe was measured at 52 GHz by the shorted …
Bafe₁₂O₁₉ Thin Films Grown At The Atomic Scale From Bafe₂O₄ And Α-Fe₂O₃ Targets, A. L. Geiler, S. D. Yoon, Y. Chen, C. N. Chinnasamy, Z. Chen, M. Geiler, V. G. Harris, C. Vittoria
Bafe₁₂O₁₉ Thin Films Grown At The Atomic Scale From Bafe₂O₄ And Α-Fe₂O₃ Targets, A. L. Geiler, S. D. Yoon, Y. Chen, C. N. Chinnasamy, Z. Chen, M. Geiler, V. G. Harris, C. Vittoria
Vincent G. Harris
Hexagonal barium ferrite (BaFe₁₂O₁₉) thin films were grown at the atomic scale by alternating target laser ablation deposition (ATLAD) of orthorhombic BaFe₂O₄ and rhombohedral α-Fe₂O₃ on < 001 > Al₂O₃ substrates. Crystallographic, magnetic, and microwave properties of the ATLAD films were determined to be comparable with single crystal quality bulk and films of BaFe₁₂O₁₉ produced by other techniques. The ability to deposit high quality hexagonal ferrite thin films by utilizing multiple targets of different chemical compositions in the deposition routine provides unique opportunities to control the ionic distribution in the unit cell of this important class of ferrite materials.
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 …