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- (Ni₀.₆₇Co₀.₂₅Fe₀.₀₈)₈₉₋ₓZr₇B₄Cuₓ (x=0 (1)
- 1) (1)
- 1-xBx (1)
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- Amorphous Fe Ge alloys (1)
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- Ball milled Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu powders (1)
- Bcc grain size (1)
- Bistable magnetic switching (1)
- Boron alloys (1)
- CVD (1)
- Co (1)
- Co-10 (1)
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- CoFe (1)
- Coefficients (1)
- Converse magnetoelectric effects (1)
- Co₂MnAl (1)
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Articles 1 - 16 of 16
Full-Text Articles in Electromagnetics and Photonics
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. Pettiford, A. Zeltser, S. Yoon, V. Harris, C. Vittoria, N. Sun
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. Pettiford, A. Zeltser, S. Yoon, V. Harris, C. Vittoria, N. Sun
Nian X. Sun
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 …
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 …
Single Crystal Fe Films Grown On Ge(001) Substrates By Magnetron Sputtering, J. Lou, A. Daigle, L. Chen, Y. Q. Wu, V. G. Harris, C. Vittoria, N. X. Sun
Single Crystal Fe Films Grown On Ge(001) Substrates By Magnetron Sputtering, J. Lou, A. Daigle, L. Chen, Y. Q. Wu, V. G. Harris, C. Vittoria, N. X. Sun
Nian X. Sun
Single crystal Fe films were grown on Ge (001) substrates by using dc magnetron sputtering. It was found that the microstructures and magnetic properties of Fe films on Ge substrates were strongly dependent upon the substrate temperature during the deposition process. There existed a narrow substrate temperature window of 125 ± 25°C for achieving single crystal Fe film on Ge. Lower substrate temperature led to polycrystalline Fe films due to limited mobility of Fe atoms, while higher substrate temperatures resulted in amorphous Fe-Ge alloy due to severe interdiffusion.
Structure And Magnetism Of Nanocrystalline Exchange-Coupled (Ni₀.₆₇Co₀.₂₅Fe₀.₀₈)₈₉₋ₓzr₇B₄Cuₓ (X=0,1) Films, S. Joshi, S. D. Yoon, A. Yang, N. X. Sun, C. Vittoria, V. G. Harris, R. Goswami, M. Willard, N. Shi
Structure And Magnetism Of Nanocrystalline Exchange-Coupled (Ni₀.₆₇Co₀.₂₅Fe₀.₀₈)₈₉₋ₓzr₇B₄Cuₓ (X=0,1) Films, S. Joshi, S. D. Yoon, A. Yang, N. X. Sun, C. Vittoria, V. G. Harris, R. Goswami, M. Willard, N. Shi
Nian X. Sun
Structural and magnetic characterizations of nanocrystalline films of (Ni₀.₆₇Co₀.₂₅Fe₀.₀₈)₈₉₋ₓZr₇B₄Cuₓ (x=0,1) alloys are reported. The films were grown on quartz substrates using pulsed laser deposition from homogeneous targets of the above compositions at substrate temperatures ranging from ambient to 600°C. Structural properties were measured by x-ray diffraction, atomic force microscopy, and transmission electron microscopy, whereas the magnetic properties were measured by vibrating sample magnetometry and ferromagnetic resonance. The resulting films exist as a two phase alloy with face-centered-cubic metallic grains suspended in an amorphous matrix. For both the x=1 and x=0 alloys, the softest magnetic properties (coercivity Hc < 0.5 Oe, 4πMs …
A Quantitative Model For The Nonlinear Response Of Fluxgate Magnetometers, A. L. Geiler, V. G. Harris, C. Vittoria, N. X. Sun
A Quantitative Model For The Nonlinear Response Of Fluxgate Magnetometers, A. L. Geiler, V. G. Harris, C. Vittoria, N. X. Sun
Nian X. Sun
An analytical nonlinear hysteresis model was developed to describe the hysteresis loops of different magnetic materials, which was capable of fitting Permalloy films as an example. As a case study this model was applied in the sensitivity analysis of the fluxgate magnetometers where accurately capturing the nonlinear behavior of the magnetic core is crucial. Straightforward analytical equation of the output voltage signal as well as its harmonic decomposition was obtained for the fluxgate magnetometer as a function of hysteresis loop parameters. Sensitivity values predicted by the model were found to be consistent with the measured values published previously. The model …
Microwave Tunability In A Gaas-Based Multiferroic Heterostructure: Co₂Mnal/Gaas/Pmn-Pt, Y. Chen, J. Gao, M. Liu, S. D. Yoon, A. L. Geiler, M. Nedoroscik, D. Heiman, N. X. Sun, C. Vittoria, V. G. Harris
Microwave Tunability In A Gaas-Based Multiferroic Heterostructure: Co₂Mnal/Gaas/Pmn-Pt, Y. Chen, J. Gao, M. Liu, S. D. Yoon, A. L. Geiler, M. Nedoroscik, D. Heiman, N. X. Sun, C. Vittoria, V. G. Harris
Nian X. Sun
A strong magnetoelectric (ME) interaction is presented in a magnetostrictive-semiconductor-piezoelectric heterostructure that consists of the Huesler alloy, Co₂MnAl, GaAs, and lead magnesium niobate-lead titanate (PMN-PT). The laminated Co₂MnAl/GaAs/PMN-PT structure, having a thickness of 19 nm/180 μm/500 μm, demonstrates a ferromagnetic resonance (FMR) field shift of 28 Oe with an external electric field of 200 V across the PMN-PT substrate. This corresponds to a resonance frequency shift of similar to 125 MHz at X-band. It yields a large ME coupling (7 Oe cm/kV) and microwave tunability (similar to 32 MHz/kV cm⁻¹), compared to other trilayer multiferroic composite structures. In addition, static …
Microwave, Magnetic, And Structural Properties Of Nanocrystalline Exchange-Coupled Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu₁ Films For High Frequency Applications, S. D. Yoon, A. K. Baraskar, A. Geiler, A. Yang, C. Pettiford, N. X. Sun, R. Goswami, M. A. Willard, C. Vittoria, V. G. Harris
Microwave, Magnetic, And Structural Properties Of Nanocrystalline Exchange-Coupled Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu₁ Films For High Frequency Applications, S. D. Yoon, A. K. Baraskar, A. Geiler, A. Yang, C. Pettiford, N. X. Sun, R. Goswami, M. A. Willard, C. Vittoria, V. G. Harris
Nian X. Sun
Nanocrystalline structured films of the alloy Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu₁ were deposited by pulsed laser ablation deposition onto fused quartz substrates. A substrate temperature of 300°C was found to produce films consisting of body-centered-cubic (bcc) metallic grains suspended in an amorphous matrix. The bcc grain size ranged from 5 - 8 nm for substrate temperatures up to 300°C. Measured values of coercivity were consistently below 4 Oe for films having a saturation magnetization, as 4π Ms, of ∽16 kG with in- plane uniaxial anisotropy fields of 25 to 30 Oe. The ferromagnetic resonance peak- to- peak derivative linewidth was measured to be 34 …
Voltage Impulse Induced Bistable Magnetization Switching In Multiferroic Heterostructures, T. X. Nan, Z. Y. Zhou, J. Lou, M. Liu, X. Yang, Y. Gao, S. Rand, N. X. Sun
Voltage Impulse Induced Bistable Magnetization Switching In Multiferroic Heterostructures, T. X. Nan, Z. Y. Zhou, J. Lou, M. Liu, X. Yang, Y. Gao, S. Rand, N. X. Sun
Nian X. Sun
We report on voltage impulse induced reversible bistable magnetization switching in FeGaB/lead zirconate titanate (PZT) multiferroic heterostructures at room temperature. This was realized through strain-mediated magnetoelectric coupling between ferroelectric PZT and ferromagnetic FeGaB layer. Two reversible and stable voltage-impulse induced mechanical strain states were obtained in the PZT by applying an electric field impulse with its amplitude smaller than the electric coercive field, which led to reversible voltage impulse induced bistable magnetization switching. These voltage impulse induced bistable magnetization switching in multiferroic heterostructures provides a promising approach to power efficient bistable magnetization switching that is crucial for information storage.
Equivalence Of Direct And Converse Magnetoelectric Coefficients In Strain-Coupled Two-Phase Systems, Jing Lou, Gerry N. Pellegrini, Ming Liu, Neil D. Mathur, Nian X. Sun
Equivalence Of Direct And Converse Magnetoelectric Coefficients In Strain-Coupled Two-Phase Systems, Jing Lou, Gerry N. Pellegrini, Ming Liu, Neil D. Mathur, Nian X. Sun
Nian X. Sun
We demonstrate an equivalence between direct and converse magnetoelectric effects in two-phase systems comprising piezoelectric and magnetostrictive materials. This was achieved by recasting the Maxwell relation in terms of the effective electrical and magnetic dipole moments for the system and comparing coupling strengths at the same electrical and magnetic d.c. biases. Our findings therefore apply to magnetoelectric systems comprising more than two phases and correct the two widely held but opposing views that are compromised by incorrect parameterization or inconsistent bias conditions.
Mems Resonant Magnetic Field Sensor Based On An Aln/Fegab Bilayer Nano-Plate Resonator, Yu Hui, Tianxiang Nan, Nian Sun, Matteo Rinaldi
Mems Resonant Magnetic Field Sensor Based On An Aln/Fegab Bilayer Nano-Plate Resonator, Yu Hui, Tianxiang Nan, Nian Sun, Matteo Rinaldi
Nian X. Sun
This paper reports on the first demonstration of an ultra-miniaturized, high frequency (215 MHz) and high sensitivity MEMS resonant magnetic field sensor based on an AlN/FeGaB bilayer nano-plate resonator capable of detecting magnetic field at nano-Tesla level. Despite of the reduced volume and the high operating frequency of the sensor, high electromechanical performances were achieved (quality factor Q ≈ 511 and electromechanical coupling coefficient kt² ≈ 1.63%). This first prototype was characterized for different magnetic field levels from 0 to 152 Oe showing a frequency sensitivity of ~ 1 Hz/nT and a limit of detection of ~ 10 nT.
The Effect Of Boron Addition On The Atomic Structure And Microwave Magnetic Properties Of Fegab Thin Films, Jinsheng Gao, Aria Yang, Yajie Chen, J. P. Kirkland, Jing Lou, Nian X. Sun, Carmine Vittoria, Vincent G. Harris
The Effect Of Boron Addition On The Atomic Structure And Microwave Magnetic Properties Of Fegab Thin Films, Jinsheng Gao, Aria Yang, Yajie Chen, J. P. Kirkland, Jing Lou, Nian X. Sun, Carmine Vittoria, Vincent G. Harris
Nian X. Sun
Varying amounts of boron were added to the host FeGa alloy to investigate its impact upon local atomic structure and magnetic and microwave properties. The impact of B upon the local atomic structure in FeGaB films was investigated by extended x-ray absorption fine structure (EXAFS) analysis. The EXAFS fitting results revealed a contraction of lattice parameters with the introduction of B. The Debye-Waller factor determined from EXAFS fitting increases as a function of boron addition and abruptly changes during the structural evolution from crystalline to amorphous that occurs near 9% B. Upon the onset of this transition the static and …
Structural And Magnetic Properties Of Ball-Milled Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu Powders, Ashish Baraskar, Yajie Chen, Soack Yoon, C. Chinnasamy, Nian Sun, Carmine Vittoria, Vincent Harris, Todd Heil, Matthew Willard
Structural And Magnetic Properties Of Ball-Milled Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu Powders, Ashish Baraskar, Yajie Chen, Soack Yoon, C. Chinnasamy, Nian Sun, Carmine Vittoria, Vincent Harris, Todd Heil, Matthew Willard
Nian X. Sun
Thick films of the Ni₁₁Co₁₁Fe₆₆Zr₇B₄Cu composition were synthesized via screen printing of the ball-milled ribbons of the above composition for possible use as planar inductors. The ribbons were obtained by rapid solidification. The resulting ribbon samples were annealed at 300 degrees C for 2 h to cause embrittlement. They were found to have soft magnetic properties (4πMs∽13 kG,ΔH ∽100 Oe, and Hc< 0.5 Oe). The brittle ribbons were ball milled using tungsten carbide vials and stainless steel balls in an inert atmosphere for various milling times. The sample milled for 10 h was found to have a 4πMs of about …
Electrostatic Tuning Of Ferromagnetic Resonance And Magnetoelectric Interactions In Ferrite-Piezoelectric Heterostructures Grown By Chemical Vapor Deposition, Ning Li, Ming Liu, Ziyao Zhou, Nian X. Sun, D. V. B. Murthy, Gopalan Srinivasan, Tonya M. Klein, Vladimir M. Petrov, Arunava Gupta
Electrostatic Tuning Of Ferromagnetic Resonance And Magnetoelectric Interactions In Ferrite-Piezoelectric Heterostructures Grown By Chemical Vapor Deposition, Ning Li, Ming Liu, Ziyao Zhou, Nian X. Sun, D. V. B. Murthy, Gopalan Srinivasan, Tonya M. Klein, Vladimir M. Petrov, Arunava Gupta
Nian X. Sun
Magnetoelectric interactions as a function of applied electric field have been studied in ferrite-ferroelectric heterostructures at microwave frequencies. The measurements are performed on 1.5–2.0 μm thick nickel ferrite (NiFe₂O₄) films grown heteroepitaxially on lead zinc niobate-lead titanate and lead magnesium niobate-lead titanate substrates using direct liquid injection chemical vapor deposition. Large shifts in the ferromagnetic resonance profile are observed in these heterostructures due to strong magnetoelectric coupling resulting from electrostatic field induced changes in the magnetic anisotropy field. Theoretical estimates of field shifts are in good agreement with the experimental data.
Effects Of Boron Addition To The Atomic Structure And Soft Magnetic Properties Of Fecob Films, Aria Yang, Hassan Imrane, Jing Lou, Johnny Kirkland, Carmine Vittoria, Nian Sun, Vincent G. Harris
Effects Of Boron Addition To The Atomic Structure And Soft Magnetic Properties Of Fecob Films, Aria Yang, Hassan Imrane, Jing Lou, Johnny Kirkland, Carmine Vittoria, Nian Sun, Vincent G. Harris
Nian X. Sun
The magnetic, microwave, and the atomic structure properties of (Fe₀.₇Co₀.₃)1-xBx sputtered films on glass substrates were investigated. The addition of boron induced a decrease in coercivity and ferromagnetic resonance linewidth. The amorphous structure was formed at x ∽0.075. Extended x-ray absorption fine structure (EXAFS) of Fe and Co showed the reduced Fourier transform (FT) amplitude, and increased Debye-Waller factors as x was increased, indicating the increased disorder due to the thermal and structural displacements. Possible Fe-B bonding was observed with a reduced bond length, which indicates boron atoms' preference for staying in the interstitial sites in bcc unit cell.
Giant Magnetoelectric Coupling And E-Field Tunability In A Laminated Ni2mnga/Lead-Magnesium-Niobate-Lead Titanate Multiferroic Heterostructure, Yajie Chen, Jingmin Wang, Ming Liu, Jing Lou, Nian X. Sun, Carmine Vittoria, Vincent G. Harris
Giant Magnetoelectric Coupling And E-Field Tunability In A Laminated Ni2mnga/Lead-Magnesium-Niobate-Lead Titanate Multiferroic Heterostructure, Yajie Chen, Jingmin Wang, Ming Liu, Jing Lou, Nian X. Sun, Carmine Vittoria, Vincent G. Harris
Nian X. Sun
The multiferroic properties of a laminated heterostructure consisting of magnetostrictive Ni2MnGa ribbon and piezoelectric lead-magnesium-niobate-lead titanate crystal are reported. A tunability of the electric field-induced magnetic field was measured by a shift in the ferromagnetic resonance (FMR) field by 230 Oe at X-band while applying an electric field of 6 kV/cm. Concomitantly, a frequency shift in the FMR of 370 MHz was observed. The sensitive tunability stems from a large linear magnetoelectric coupling coefficient, A=41 Oe cm/kV, measured in the heterostructure. This represents a new class of metallic multiferroic heterostructures that operate at microwave frequencies.
Pulsed Laser Ablation Deposition Of Nanocrystalline Exchange-Coupled Ni₁₁Co₁₁Fe₆₇₋ₓzr₇B₄Cux (X=0,1) Films For Planar Inductor Applications, Ashish K. Baraskar, Soack Dae Yoon, Anton Geiler, Aria Yang, C. N. Chinnasamy, Yajie Chen, Nian Sun, Carmine Vittoria, Ramasis Goswami, Matthew Willard, Vincent G. Harris
Pulsed Laser Ablation Deposition Of Nanocrystalline Exchange-Coupled Ni₁₁Co₁₁Fe₆₇₋ₓzr₇B₄Cux (X=0,1) Films For Planar Inductor Applications, Ashish K. Baraskar, Soack Dae Yoon, Anton Geiler, Aria Yang, C. N. Chinnasamy, Yajie Chen, Nian Sun, Carmine Vittoria, Ramasis Goswami, Matthew Willard, Vincent G. Harris
Nian X. Sun
Nanocrystalline films of the Ni₁₁Co₁₁Fe₆₇₋ₓZr₇B₄Cux (x=0,1) composition were deposited on fused quartz substrates by pulsed laser deposition. For the films ofNi₁₁Co₁₁Fe₆₆Zr₇B₄Cu, the bcc grain size ranged from 5 to 8 nm in the films deposited at substrate temperatures from ambient to 300°C. Films grown at a substrate temperature of 300°C were found to have optimal magnetic properties including minima in the coercivity and ferromagnetic resonance (FMR) linewidth. The magnetic characterization studies showed coercivity Hc < 5 Oe, 4πMs ∽16 kG, and in-plane uniaxial anisotropy field (HA)∽25-30 Oe. The ferromagnetic resonance linewidth was measured to be 34 Oe and zero magnetic field …