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Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Nian X. Sun
Films consisting of Zn₁₋ₓFeₓO were prepared by alternating-target laser ablation deposition. The Fe doping levels ranged from x=0.016 to 0.125 at. %. X-ray diffraction and energy dispersive x-ray spectroscopy measurements showed only (002n) reflections of the ZnO host and confirmation of the Fe concentration, respectively. For films grown on (001) Al₂O₃ at 300 K, room temperature average saturation magnetization, < 4πMs >, measured from superconducting quantum interference device (SQUID) hysteresis loops for x=0.125 ± 0.025 was 172 G. Although SQUID measurements were sensitive to the average value of the saturation magnetization, ferrimagnetic resonance measurements appeared to be sensitive only to the saturation …
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. Yoon, Y. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. Harris
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. Yoon, Y. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. Harris
Donald Heiman
Films consisting of Zn₁₋ₓFeₓO were prepared by alternating-target laser ablation deposition. The Fe doping levels ranged from x=0.016 to 0.125 at. %. X-ray diffraction and energy dispersive x-ray spectroscopy measurements showed only (002n) reflections of the ZnO host and confirmation of the Fe concentration, respectively. For films grown on (001) Al₂O₃ at 300 K, room temperature average saturation magnetization, < 4πMs >, measured from superconducting quantum interference device (SQUID) hysteresis loops for x=0.125 ± 0.025 was 172 G. Although SQUID measurements were sensitive to the average value of the saturation magnetization, ferrimagnetic resonance measurements appeared to be sensitive only to the saturation …
Properties Of Pulsed Laser Deposited Scandium-Doped Barium Hexaferrite Films, S. A. Oliver, M. L. Chen, C. Vittoria, P. Lubitz
Properties Of Pulsed Laser Deposited Scandium-Doped Barium Hexaferrite Films, S. A. Oliver, M. L. Chen, C. Vittoria, P. Lubitz
Carmine Vittoria
The properties of thin films of BaScₓFe₁₂₋ₓO₁₉ (x = 0.4) were determined by structural and magnetic measurements. Films were deposited by pulsed laser ablation deposition onto c-plane sapphire at oxygen pressures between 10 and 100 mTorr. X-ray diffraction measurements showed all films to be single-phase c-axis oriented hexaferrites with expanded c-axis lattice constants compared to x = 0 films. Magnetometry measurements showed that all films had the easy axis (c-axis) normal to the film plane, with a mean saturation magnetization value of 3.8 kG. The mean uniaxial anisotropy field value was 10.6 kOe. This ability to adjust the uniaxial anisotropy …
Structural And Size Dependent Magnetic Properties Of Single Phase Nanostructured Gadolinium-Iron-Garnet Under High Magnetic Field Of 32 Tesla, C. N. Chinnasamy, J. M. Greneche, M. Guillot, B. Latha, T. Sakai, C. Vittoria, V. G. Harris
Structural And Size Dependent Magnetic Properties Of Single Phase Nanostructured Gadolinium-Iron-Garnet Under High Magnetic Field Of 32 Tesla, C. N. Chinnasamy, J. M. Greneche, M. Guillot, B. Latha, T. Sakai, C. Vittoria, V. G. Harris
Carmine Vittoria
Here we report the single phase nanostructured Gd₃Fe₅O₁₂ garnets with different grain sizes (bulk, 75, 47, 35, and 22 nm) were prepared by ball milling for various milling times. Both the average grain size and the lattice parameter were estimated from the x-ray diffraction line broadening. The 57Fe Mӧssbauer spectra were recorded at 300 and 77 K for the samples with different grain sizes clearly evidenced the formation of Fe²⁺ ions induced by milling and the content of Fe²⁺ increases with milling time. At 4.2 K, a significant increase in saturation magnetization (+11%) has been observed for the 47 nm …
Structural And Size Dependent Magnetic Properties Of Single Phase Nanostructured Gadolinium-Iron-Garnet Under High Magnetic Field Of 32 Tesla, C. N. Chinnasamy, J. M. Greneche, M. Guillot, B. Latha, T. Sakai, C. Vittoria, V. G. Harris
Structural And Size Dependent Magnetic Properties Of Single Phase Nanostructured Gadolinium-Iron-Garnet Under High Magnetic Field Of 32 Tesla, C. N. Chinnasamy, J. M. Greneche, M. Guillot, B. Latha, T. Sakai, C. Vittoria, V. G. Harris
Vincent G. Harris
Here we report the single phase nanostructured Gd₃Fe₅O₁₂ garnets with different grain sizes (bulk, 75, 47, 35, and 22 nm) were prepared by ball milling for various milling times. Both the average grain size and the lattice parameter were estimated from the x-ray diffraction line broadening. The 57Fe Mӧssbauer spectra were recorded at 300 and 77 K for the samples with different grain sizes clearly evidenced the formation of Fe²⁺ ions induced by milling and the content of Fe²⁺ increases with milling time. At 4.2 K, a significant increase in saturation magnetization (+11%) has been observed for the 47 nm …
Structure, Magnetic, And Microwave Properties Of Thick Ba-Hexaferrite Films Epitaxially Grown On Gan/Al₂O₃ Substrates, Z. Chen, A. Yang, K. Mahalingam, K. L. Averett, J. Gao, G. J. Brown, C. Vittoria, V. G. Harris
Structure, Magnetic, And Microwave Properties Of Thick Ba-Hexaferrite Films Epitaxially Grown On Gan/Al₂O₃ Substrates, Z. Chen, A. Yang, K. Mahalingam, K. L. Averett, J. Gao, G. J. Brown, C. Vittoria, V. G. Harris
Vincent G. Harris
Thick barium hexaferrite [BaO∙(Fe₂O₃)₆] films, having the magnetoplumbite structure (i.e., Ba M), were epitaxially grown on c-axis oriented GaN/Al₂O₃ substrates by pulsed laser deposition followed by liquid phase epitaxy. X-ray diffraction showed (0,0,2n) crystallographic alignment with pole figure analyses confirming epitaxial growth. High resolution transmission electron microscopy images revealed magnetoplumbite unit cells stacked with limited interfacial mixing. Saturation magnetization, 4πMs, was measured for as-grown films to be 4.1 ± 0.3 kG with a perpendicular magnetic anisotropy field of 16 ± 0.3 kOe. Ferromagnetic resonance linewidth, the peak-to-peak power absorption derivative at 53 GHz, was 86 Oe. These properties will prove …
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Vincent G. Harris
Films consisting of Zn₁₋ₓFeₓO were prepared by alternating-target laser ablation deposition. The Fe doping levels ranged from x=0.016 to 0.125 at. %. X-ray diffraction and energy dispersive x-ray spectroscopy measurements showed only (002n) reflections of the ZnO host and confirmation of the Fe concentration, respectively. For films grown on (001) Al₂O₃ at 300 K, room temperature average saturation magnetization, < 4πMs >, measured from superconducting quantum interference device (SQUID) hysteresis loops for x=0.125 ± 0.025 was 172 G. Although SQUID measurements were sensitive to the average value of the saturation magnetization, ferrimagnetic resonance measurements appeared to be sensitive only to the saturation …
Structure, Magnetic, And Microwave Properties Of Thick Ba-Hexaferrite Films Epitaxially Grown On Gan/Al₂O₃ Substrates, Z. Chen, A. Yang, K. Mahalingam, K. L. Averett, J. Gao, G. J. Brown, C. Vittoria, V. G. Harris
Structure, Magnetic, And Microwave Properties Of Thick Ba-Hexaferrite Films Epitaxially Grown On Gan/Al₂O₃ Substrates, Z. Chen, A. Yang, K. Mahalingam, K. L. Averett, J. Gao, G. J. Brown, C. Vittoria, V. G. Harris
Carmine Vittoria
Thick barium hexaferrite [BaO∙(Fe₂O₃)₆] films, having the magnetoplumbite structure (i.e., Ba M), were epitaxially grown on c-axis oriented GaN/Al₂O₃ substrates by pulsed laser deposition followed by liquid phase epitaxy. X-ray diffraction showed (0,0,2n) crystallographic alignment with pole figure analyses confirming epitaxial growth. High resolution transmission electron microscopy images revealed magnetoplumbite unit cells stacked with limited interfacial mixing. Saturation magnetization, 4πMs, was measured for as-grown films to be 4.1 ± 0.3 kG with a perpendicular magnetic anisotropy field of 16 ± 0.3 kOe. Ferromagnetic resonance linewidth, the peak-to-peak power absorption derivative at 53 GHz, was 86 Oe. These properties will prove …
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Room Temperature Magnetism In Semiconducting Films Of Zno Doped With Ferric Ions, S. D. Yoon, Y. J. Chen, D. Heiman, A. Yang, N. Sun, C. Vittoria, V. G. Harris
Carmine Vittoria
Films consisting of Zn₁₋ₓFeₓO were prepared by alternating-target laser ablation deposition. The Fe doping levels ranged from x=0.016 to 0.125 at. %. X-ray diffraction and energy dispersive x-ray spectroscopy measurements showed only (002n) reflections of the ZnO host and confirmation of the Fe concentration, respectively. For films grown on (001) Al₂O₃ at 300 K, room temperature average saturation magnetization, < 4πMs >, measured from superconducting quantum interference device (SQUID) hysteresis loops for x=0.125 ± 0.025 was 172 G. Although SQUID measurements were sensitive to the average value of the saturation magnetization, ferrimagnetic resonance measurements appeared to be sensitive only to the saturation …
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 …
Cation Engineering Of Cu-Ferrite Films Deposited By Alternating Target Laser Ablation Deposition, Aria Yang, Zhaohui Chen, Shaheen M. Islam, Carmine Vittoria, V. G. Harris
Cation Engineering Of Cu-Ferrite Films Deposited By Alternating Target Laser Ablation Deposition, Aria Yang, Zhaohui Chen, Shaheen M. Islam, Carmine Vittoria, V. G. Harris
Vincent G. Harris
Epitaxial copper ferrite thin films were deposited on MgO substrates by the alternating target laser ablation deposition method. A series of films was studied to explore the impact of oxygen operating pressure, substrate temperature, and the ratio of laser shots incident on each target upon the magnetic, structural, and atomic structural properties. The highest saturation magnetization, 2800 G, was achieved at a 90 mTorr oxygen pressure and at 650 degrees C for the substrate temperature. This value is 65% higher than the room temperature magnetization for bulk equilibrium samples. The inversion parameter was measured by extended x-ray absorption fine structure …
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
Carmine Vittoria
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 …
Magnetic And Microwave Properties Of Ion-Beam-Sputtered Amorphous Fexco80-Xb₁₅Si5 Films, V. G. Harris, S. A. Oliver, W. B. Nowak, C. Vittoria
Magnetic And Microwave Properties Of Ion-Beam-Sputtered Amorphous Fexco80-Xb₁₅Si5 Films, V. G. Harris, S. A. Oliver, W. B. Nowak, C. Vittoria
Vincent G. Harris
Magnetically soft amorphous films of FeₓCO₈₀₋ₓB₁₅Si₅ (x = 0,6,23,40,70,80) were ion beam sputter deposited onto fused quartz for static and microwave magnetic characterization. Films ranged in thickness from 220 to 260 nm and were deposited at rates of 0.1-0.2 nm/s. Saturation magnetization, coercivity, and loop squareness values were extracted from hysteresis loops generated by a vibrating sample magnetometer. Ferromagnetic resonance measurements were taken using a 9.5-GHz cavity with the applied magnetic field both parallel and perpendicular to the plane of the film, yielding values for the g factor, anisotropy field, effective magnetization, and linewidth. Well resolved quadratic spin-wave resonance spectra …
Epitaxial Growth Of Pbfe₁₂O₁₉ Thin Films By Alternating Target Laser Ablation Deposition Of Fe₂O₃ And Pbo, A. L. Geiler, Y. He, S. D. Yoon, A. Yang, Y. Chen, V. G. Harris, C. Vittoria
Epitaxial Growth Of Pbfe₁₂O₁₉ Thin Films By Alternating Target Laser Ablation Deposition Of Fe₂O₃ And Pbo, A. L. Geiler, Y. He, S. D. Yoon, A. Yang, Y. Chen, V. G. Harris, C. Vittoria
Vincent G. Harris
Oriented M-type hexaferrite thin films are deposited using the alternating target laser ablation deposition (ATLAD) technique utilizing PbO and Fe₂O₃ targets. Crystallographic, dc magnetic, and microwave characterization results confirming the presence of a hexagonal PbFe₁₂O₁₉ phase are presented. We conclude that the ATLAD technique holds great promise for layer by layer deposition of various hexaferrite materials, the properties of which can be adjusted by varying the composition of the targets as well as the number of laser shots from each target during the deposition process. This would provide control over the uniaxial anisotropy fields and saturation magnetization values that was …
Cation Engineering Of Cu-Ferrite Films Deposited By Alternating Target Laser Ablation Deposition, Aria Yang, Zhaohui Chen, Shaheen M. Islam, Carmine Vittoria, V. G. Harris
Cation Engineering Of Cu-Ferrite Films Deposited By Alternating Target Laser Ablation Deposition, Aria Yang, Zhaohui Chen, Shaheen M. Islam, Carmine Vittoria, V. G. Harris
Carmine Vittoria
Epitaxial copper ferrite thin films were deposited on MgO substrates by the alternating target laser ablation deposition method. A series of films was studied to explore the impact of oxygen operating pressure, substrate temperature, and the ratio of laser shots incident on each target upon the magnetic, structural, and atomic structural properties. The highest saturation magnetization, 2800 G, was achieved at a 90 mTorr oxygen pressure and at 650 degrees C for the substrate temperature. This value is 65% higher than the room temperature magnetization for bulk equilibrium samples. The inversion parameter was measured by extended x-ray absorption fine structure …
Epitaxial Growth Of Pbfe₁₂O₁₉ Thin Films By Alternating Target Laser Ablation Deposition Of Fe₂O₃ And Pbo, A. L. Geiler, Y. He, S. D. Yoon, A. Yang, Y. Chen, V. G. Harris, C. Vittoria
Epitaxial Growth Of Pbfe₁₂O₁₉ Thin Films By Alternating Target Laser Ablation Deposition Of Fe₂O₃ And Pbo, A. L. Geiler, Y. He, S. D. Yoon, A. Yang, Y. Chen, V. G. Harris, C. Vittoria
Carmine Vittoria
Oriented M-type hexaferrite thin films are deposited using the alternating target laser ablation deposition (ATLAD) technique utilizing PbO and Fe₂O₃ targets. Crystallographic, dc magnetic, and microwave characterization results confirming the presence of a hexagonal PbFe₁₂O₁₉ phase are presented. We conclude that the ATLAD technique holds great promise for layer by layer deposition of various hexaferrite materials, the properties of which can be adjusted by varying the composition of the targets as well as the number of laser shots from each target during the deposition process. This would provide control over the uniaxial anisotropy fields and saturation magnetization values that was …
Magnetic And Microwave Properties Of Ion-Beam-Sputtered Amorphous Fexco80-Xb₁₅Si5 Films, V. G. Harris, S. A. Oliver, W. B. Nowak, C. Vittoria
Magnetic And Microwave Properties Of Ion-Beam-Sputtered Amorphous Fexco80-Xb₁₅Si5 Films, V. G. Harris, S. A. Oliver, W. B. Nowak, C. Vittoria
Carmine Vittoria
Magnetically soft amorphous films of FeₓCO₈₀₋ₓB₁₅Si₅ (x = 0,6,23,40,70,80) were ion beam sputter deposited onto fused quartz for static and microwave magnetic characterization. Films ranged in thickness from 220 to 260 nm and were deposited at rates of 0.1-0.2 nm/s. Saturation magnetization, coercivity, and loop squareness values were extracted from hysteresis loops generated by a vibrating sample magnetometer. Ferromagnetic resonance measurements were taken using a 9.5-GHz cavity with the applied magnetic field both parallel and perpendicular to the plane of the film, yielding values for the g factor, anisotropy field, effective magnetization, and linewidth. Well resolved quadratic spin-wave resonance spectra …