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Articles 1 - 8 of 8
Full-Text Articles in Engineering
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 …
Magnetic Anisotropy And Crystalline Texture In Bao(Fe₂O₃)₆ Thin Films Deposited On Gan/Al₂O₃, Paul R. Ohodnicki, K. Y. Goh, Yuranan Hanlumyuang, K. Ramos, Michael E. Mchenry, Zhuhua Cai, Katherine Ziemer, Hadis Morkoc, Necmi Biyikli, Zhaohui Chen, C. Vittoria, Vincent Girard Harris (1962-)
Magnetic Anisotropy And Crystalline Texture In Bao(Fe₂O₃)₆ Thin Films Deposited On Gan/Al₂O₃, Paul R. Ohodnicki, K. Y. Goh, Yuranan Hanlumyuang, K. Ramos, Michael E. Mchenry, Zhuhua Cai, Katherine Ziemer, Hadis Morkoc, Necmi Biyikli, Zhaohui Chen, C. Vittoria, Vincent Girard Harris (1962-)
Vincent G. Harris
BaO(Fe₂O₃)₆ (BaM) thin films were deposited by pulsed laser deposition on GaN/Al₂O₃ substrates. A pole figure obtained from the (006) reflection indicated that ~81% of the film volume had the c axis tilted less than 5° from the film normal. A low anisotropy field was inferred from vector coil vibrating sample magnetometer (VVSM) measurements. The reduction in Hₐ from literature values and a two-step switching of the easy axis magnetization is postulated to result from interdiffusion and misalignment effects. To alleviate interdiffusion and to improve the c-axis alignment, experiments were repeated with lower deposition temperatures, thinner films, and MgO buffer …
Correlation Between Texture, Anisotropy, And Vector Magnetization Processes Investigated By Two-Dimensional Vector Vibrating Sample Magnetometry In Bao(Fe₂O₃)₆ Thin Film, Paul Ohodnicki, K. Goh, Michael Mchenry, Katherine Ziemer, Zhaohui Chen, C. Vittoria, Vincent Harris (1962-)
Correlation Between Texture, Anisotropy, And Vector Magnetization Processes Investigated By Two-Dimensional Vector Vibrating Sample Magnetometry In Bao(Fe₂O₃)₆ Thin Film, Paul Ohodnicki, K. Goh, Michael Mchenry, Katherine Ziemer, Zhaohui Chen, C. Vittoria, Vincent Harris (1962-)
Vincent G. Harris
High ferromagnetic resonance frequencies and low linewidths in BaO(Fe₂O₃)₆ thin films are achieved by obtaining a low-dispersion of crystallite easy c axes normal to the film. X-ray diffraction and magnetic force microscopy are used to characterize texture and magnetic domain structure for a BaO(Fe₂O₃)₆ film deposited on (0001) SiC with a MgO (111) template layer. Strong c-axis texture normal to the film is observed resulting in strong uniaxial anisotropy. The consequent vector magnetization processes due to a combination of domain wall motion and magnetization rotation are characterized by two dimensional vector coil vibrating sample magnetometry (VVSM).
Epitaxial Growth Of M-Type Ba-Hexaferrite Films On Mgo (111) || Sic (0001) With Low Ferromagnetic Resonance Linewidths, Zhaohui Chen, Aria Fan Yang, Anton Geiler, Vincent Girard Harris (1962-), C. Vittoria, Paul R. Ohodnicki, K. Y. Goh, Michael E. Mchenry, Zhuhua Cai, Trevor L. Goodrich, Katherine S. Ziemer
Epitaxial Growth Of M-Type Ba-Hexaferrite Films On Mgo (111) || Sic (0001) With Low Ferromagnetic Resonance Linewidths, Zhaohui Chen, Aria Fan Yang, Anton Geiler, Vincent Girard Harris (1962-), C. Vittoria, Paul R. Ohodnicki, K. Y. Goh, Michael E. Mchenry, Zhuhua Cai, Trevor L. Goodrich, Katherine S. Ziemer
Vincent G. Harris
Barium hexaferrite (BaM) films were deposited on 10 nm MgO (111) films on 6H silicon carbide (0001) substrates by pulsed laser deposition from a homogeneous BaFe₁₂O₁₉ target. The MgO layer, deposited by molecular beam epitaxy, alleviated lattice mismatch and interdiffusion between film and substrate. X-ray diffraction showed strong crystallographic alignment while pole figures exhibited reflections consistent with epitaxial growth. After optimized annealing, these BaM films have a perpendicular magnetic anisotropy field of 16 900 Oe, a magnetization (as 4πs) of 4.4 kG, and a ferromagnetic resonance peak-to-peak derivative linewidth at 53 GHz of 96 Oe, thus demonstrating sufficient properties for …
Structure And Magnetism Of Ba-Hexaferrite Films Grown On Single Crystal 6-H Sic With Graduated Interfacial Mgo Buffer Layers, Zhaohui Chen, Aria Fan Yang, Zhuhua Cai, Soack Dae Yoon, Katherine S. Ziemer, C. Vittoria, Vincent Girard Harris (1962-)
Structure And Magnetism Of Ba-Hexaferrite Films Grown On Single Crystal 6-H Sic With Graduated Interfacial Mgo Buffer Layers, Zhaohui Chen, Aria Fan Yang, Zhuhua Cai, Soack Dae Yoon, Katherine S. Ziemer, C. Vittoria, Vincent Girard Harris (1962-)
Vincent G. Harris
M-type barium hexaferrite films were processed by pulsed laser deposition on single-crystal 6-H silicon carbide substrates. MgO buffer and barrier layers were introduced to improve the film quality. Samples were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry, and ferromagnetic resonance (FMR). X-ray θ − 2θ diffraction measurements indicated a strong (0, 0, 2n) crystallographic alignment. The magnetization of the BaM film is comparable to bulk values (4πMs ∼ 4320 G). A derivative power FMR linewidth of 500 Oe was measured at 55 GHz for the as-deposited films. This paper explores a …
The Effects Of Room Temperature Aging Upon The Magnetic Properties Of Ba-Hexaferrite Films Grown On 6h-Sic Substrates, Zhaohui Chen, Zhuhua Cai, Aria Fan Yang, Katherine S. Ziemer, C. Vittoria, Vincent Girard Harris (1962-)
The Effects Of Room Temperature Aging Upon The Magnetic Properties Of Ba-Hexaferrite Films Grown On 6h-Sic Substrates, Zhaohui Chen, Zhuhua Cai, Aria Fan Yang, Katherine S. Ziemer, C. Vittoria, Vincent Girard Harris (1962-)
Vincent G. Harris
The successes of making acceptable magnetic properties BaM films by different techniques based on pulsed laser deposition were reported in the past years. The key was to introduce a proper buffer layer to promote two dimensional growths on these semiconductor material substrates. After years, we go back to characterize these samples made by different processings. The purpose of this experiment is to explore the role of the buffer layers especially with the time dependence and thus demonstrate our film suitable for the potential future application. These samples are characterized by scanning electron microscopy, x-ray diffraction, and vibrating sample magnetometry comparing …
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Yoon, Tomokuza Sakai, Anton Geiler, Aria Yang, Yongxue He, Katherine Ziemer, Nian Sun, C. Vittoria
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Yoon, Tomokuza Sakai, Anton Geiler, Aria Yang, Yongxue He, Katherine Ziemer, Nian Sun, C. Vittoria
Vincent G. Harris
Next generation magnetic microwave devices require ferrite films to be thick (>300 μm), self-biased (high remanent magnetization), and low loss in the microwave and millimeter wave bands. Here we examine recent advances in the processing of thick Ba-hexaferrite (M-type) films using pulsed laser deposition (PLD), liquid-phase epitaxy, and screen printing. These techniques are compared and contrasted as to their suitability for microwave materials processing and industrial production. Recent advances include the PLD growth of BaM on wide-band-gap semiconductor substrates and the development of thick, self-biased, low-loss BaM films by screen printing.
Magnetic And Structural Investigation Of Heat Treated Ion Beam Sputtered Amorphous Co₇₄Fe₆B₁₅Si₅ Films, V. Harris, S. Oliver, W. Nowak, C. Vittoria, R. Culbertson, W. Elam, K. Kim
Magnetic And Structural Investigation Of Heat Treated Ion Beam Sputtered Amorphous Co₇₄Fe₆B₁₅Si₅ Films, V. Harris, S. Oliver, W. Nowak, C. Vittoria, R. Culbertson, W. Elam, K. Kim
Vincent G. Harris
As-deposited and annealed specimens of ion beam sputtered amorphous Co₇₄Fe₆B₁₅Si₅ thin films were examined to explore the correlation between changes in magnetic properties and atomic structure. Specimens were characterized magnetically, by traditional ac and dc techniques and structurally, via conversion-electron extended x-ray absorption fine structure analysis. Results show significant ordering of the higher order atomic shells around the transition metal ions well below the crystallization temperature. This ordering evolves into a body- centered-cubic configuration around both the Co and Fe ions. Increases in nearest neighbor peak positions in the EXAFS Fourier transforms were observed to correlate with increasing annealing temperatures. …