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Full-Text Articles in Physics
High Coercivity Smfealc Thin Films Fabricated By Multilayer Sputtering, M.L. Yan, Z.S. Shan, Yi Liu, David J. Sellmyer
High Coercivity Smfealc Thin Films Fabricated By Multilayer Sputtering, M.L. Yan, Z.S. Shan, Yi Liu, David J. Sellmyer
David Sellmyer Publications
Multilayer sputtering of SmFe/C(Al) plus appropriate thermal processing has been used to fabricate SmFeC thin films with A1 substitution for Fe. It was found that the SmFeAlC thin films exhibited exceptionally high Coercivities. A coercivity of 28 kOe was realized for the thin film with structure of Ta(l000 Å)/|SmFe(40Å)/ C(Al)(5Å)]x50/Ta(200Å) with subsequent annealing at 650°C.
Magnetic And Structural Properties Of Sm2Fe10Co7/MXCY Thin Films, I.A. Al-Omari, N. J. Cunningham, David J. Sellmyer
Magnetic And Structural Properties Of Sm2Fe10Co7/MXCY Thin Films, I.A. Al-Omari, N. J. Cunningham, David J. Sellmyer
David Sellmyer Publications
The structural and magnetic properties of Sm2Fe10Co7/MxCy (M=A1 and Si; x≥0 and y≥0) multilayer films with Ta underlayers and overlayers before and after annealing at 700 °C for 5-12 min have been fabricated and studied. Structural studies show evidence of layer diffusion upon annealing. X-ray diffraction shows that the samples after annealing consist of a soft phase, α -Fe, and a hard phase with the 2-17-type structure. The samples studied have in-plane anisotropy with single hysteresis loops indicating that the two phases are strongly exchange coupled. After annealing, the coercivity of …
Remanence Enhancement And Exchange Coupling In Prco/Co Films, J. Ping Liu, Yi Liu, Z.S. Shan, David J. Sellmyer
Remanence Enhancement And Exchange Coupling In Prco/Co Films, J. Ping Liu, Yi Liu, Z.S. Shan, David J. Sellmyer
David Sellmyer Publications
PrCo/Co multilayer thin films have been prepared by sputtering. After heat treatment, high coercivity is developed and the remanence is enhanced for the insertion of the CO layers and the exchange coupling between the hard phase and the soft phase, which leads to high energy products of the composite magnets. The nanostructure of the films has been studied by TEM. It is found that the grain size of the films with high energy products is in the range from 10 to 25 nanometers.
Magnetic Hardening In Fept Nanostructured Films, J. Ping Liu, Yi Liu, C.P. Luo, Z.S. Shan
Magnetic Hardening In Fept Nanostructured Films, J. Ping Liu, Yi Liu, C.P. Luo, Z.S. Shan
David Sellmyer Publications
FePt films have been prepared by sputtering Fe/Pt multilayers onto glass or silicon substrates. The thickness of the Fe and Pt layers was adjusted with the Fe:Pt atomic ratio from about 1:1 to 2:1. Magnetic hardening is observed after heat treatment at elevated temperatures, which led to coercivity values exceeding 20 kOe in samples with an Fe:Pt ratio around 1.2:1. The hardening originates from the formation of the tetragonal FePt phase with high magnetocrystalline anisotropy and a favorable microstructure. Two-phase composite films containing hard and soft phases were obtained when the Fe:Pt ratio increased. Under optimized processing conditions, composite films …
Nanostructure And Magnetic Anisotropy Of Co/Au Multilayers, Yi Liu, Z.S. Shan, David J. Sellmyer
Nanostructure And Magnetic Anisotropy Of Co/Au Multilayers, Yi Liu, Z.S. Shan, David J. Sellmyer
David Sellmyer Publications
Multilayer Co/Au films were deposited on 40 nm Au underlayer by magnetron sputtering. The Co thickness is kept constant at 0.5 nm while the Au thickness is varied from 0.5 to 8 nm. Magnetic measurements show that the perpendicular anisotropy of the films changes from 3 × 106 to 1.5 × 106 erg/cm3 as the Au thickness changes from 6 to 1 nm. Two films of (Co 0.5 nm/Au 6 nm) × 9/Au 40 nm (denoted Au6) and (Co 0.5 nm/Au 1 nm) × 50/Au 40 nm (denoted Au1) were examined by transmission electron microscopy. For the …
Magnetic Properties And Switching Volumes Of Nanocrystalline Smfesic Films, S.Y. Zhang, Z.S. Shan, Yi Liu, T.Y. Zhao, J.G. Zhao, B.G. Shen, W.S. Zhan, David J. Sellmyer
Magnetic Properties And Switching Volumes Of Nanocrystalline Smfesic Films, S.Y. Zhang, Z.S. Shan, Yi Liu, T.Y. Zhao, J.G. Zhao, B.G. Shen, W.S. Zhan, David J. Sellmyer
David Sellmyer Publications
Systematic studies of the effects of Si addition on the magnetic and magnetization reversal properties of SmFeSiC films are presented. The magnetic switching volume and other magnetic parameters (e.g., coercivity) are strongly dependent upon the Si content. Correlations between switching volume, coercivity, and the intergrain interactions are discussed.
Correlation Of Switching Volume With Magnetic Properties, Microstructure, And Media Noise In Cocr(Pt)Ta Thin Films, C. Gao, Z.S. Shan, R. Malmhall, Yi Liu, H.J. Richter, A. Barney, G.C. Rauch, David J. Sellmyer
Correlation Of Switching Volume With Magnetic Properties, Microstructure, And Media Noise In Cocr(Pt)Ta Thin Films, C. Gao, Z.S. Shan, R. Malmhall, Yi Liu, H.J. Richter, A. Barney, G.C. Rauch, David J. Sellmyer
David Sellmyer Publications
The technique of "field sweep-rate dependence of coercivity" together with the delta-M curves, transmission electron microscopy, and media noise measurement have been employed to reveal the correlation among the magnetic switching volume, physical grain size, intergrain interaction, and noise properties. The switching volume for both CoCrTa and CoCrPtTa films was found to be ~ 15 nm in diameter, and weakly dependent on grain size and coercivity for the systems studied. In films with physical grain size larger than the switching volume, strong intergrain interaction and high media noise is observed. In films with the physical grain size close to the …
Interlayer Coupling In Nife/Mo Multilayers And Effect Of Fe Underlayer, M.L. Yan, Z.S. Shan, David J. Sellmyer, W.Y. Lai
Interlayer Coupling In Nife/Mo Multilayers And Effect Of Fe Underlayer, M.L. Yan, Z.S. Shan, David J. Sellmyer, W.Y. Lai
David Sellmyer Publications
We report our studies of exchange coupling in NiFe/Mo multilayers with and without Fe underlayer. The interlayer coupling of NiFe layers across the Mo spacer as well as the magnetic exchange coupling between Fe underlayer and the NiFe/Mo multilayers were observed: The interlayer coupling in NiFe/Mo multilayers exhibits the typical oscillations as a function of the Mo spacer with a period of about 11 Å, and the magnetic exchange coupling between Fe underlayer and the NiFe/Mo multilayers is strongly dependent on the thickness of the Mo spacer tMo and the bilayer number N of NiFe/Mo multilayers. For the [NiFe(20 …