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Full-Text Articles in Physics
Magnetic And Structural Properties Of Melt-Spun Rare-Earth Transition-Metal Intermetallics With Thmn12 Structure, E.W. Singleton, J. Strzeszewski, George C. Hadjipanayis, David J. Sellmyer
Magnetic And Structural Properties Of Melt-Spun Rare-Earth Transition-Metal Intermetallics With Thmn12 Structure, E.W. Singleton, J. Strzeszewski, George C. Hadjipanayis, David J. Sellmyer
David Sellmyer Publications
The magnetic and structural properties of melt-spun R8Fe84Ti8 with R=Nd, Sm, Dy, Gd and R8 (Fe,Co) 76 [V(Mo)] 16 with R=Nd, Sm have been studied with x-ray diffraction, transmission electron microscopy, and magnetic measurements. The tetragonal ThMn12-type structure was found in all alloys after annealing at about 700 °C. The Curie temperature (Tc) of the as-spun amorphous samples was in the range of 40–100 °C. Crystallized Nd8 (Fe1-xCox)84Ti8 samples with the 1:12 structure have a Tc around 250 °C for …
Structure And Magnetic Properties Of Nanostructured Dy/Transition-Metal Multilayered Films, Z.S. Shan, David J. Sellmyer
Structure And Magnetic Properties Of Nanostructured Dy/Transition-Metal Multilayered Films, Z.S. Shan, David J. Sellmyer
David Sellmyer Publications
We report the results of magnetic and microstructural studies for T/Dy (T=Fe, Co, Ni) compositionally modulated films prepared in a multiple-gun sputtering system. The perpendicular anisotropy and magnetization were measured systematically for X-Å Fe/Y-Å Dy and X-Å Co/Y-Å Dy films. The layer-thickness dependence of the magnetization for Co/Dy and Fe/Dy was interpreted in terms of the antiparallel coupling between transition-metal and Dy magnetic moments. For Co/Dy films the ranges of X and Y required for perpendicular anisotropy were determined. A comparision of the structural and magnetic properties of Ni/Dy, Co/Dy, and Fe/Dy is given and the origin of the perpendicular …
Magnetic And Structural Properties Of Nd2Fe14B Permanent-Magnet Films And Multilayers With Fe And Ag, K.D. Aylesworth, Z.R. Zhao, David J. Sellmyer, George C. Hadjipanayis
Magnetic And Structural Properties Of Nd2Fe14B Permanent-Magnet Films And Multilayers With Fe And Ag, K.D. Aylesworth, Z.R. Zhao, David J. Sellmyer, George C. Hadjipanayis
David Sellmyer Publications
The effects of sputtering conditions on the structure and magnetic properties of Nd2 (Fe0.9Co0.1)14B films and multilayers are reported. The samples were sputtered onto temperature-controlled mica and Ta substrates, at temperatures between 20 and 620 °C. X-ray diffraction results indicate that films deposited directly onto 500–600 °C substrates with Fe buffer layers are nearly single-phase materials with the c axis of the grains largely perpendicular to the film plane. Room-temperature magnetization measurements to 17.4 kOe indicate that these films have strong perpendicular anisotropy with coercivities in excess of 10 kOe and magnetizations greater …
Electronic Structure And Surface Reactivity Of Nd2Fe14B And Related Compounds, Sitaram Jaswal, Marjorie Langell, Y.G. Ren, M.A. Engelhardt, David J. Sellmyer
Electronic Structure And Surface Reactivity Of Nd2Fe14B And Related Compounds, Sitaram Jaswal, Marjorie Langell, Y.G. Ren, M.A. Engelhardt, David J. Sellmyer
David Sellmyer Publications
Studies of electronic and magnetic structure and surface reactivity are reported for R2T14B compounds where R=Y, Nd, Gd, and T=Fe, Co. The calculations employed the self-consistent, spin-polarized linear-muffin-tin orbital method. Experiments included ultraviolet, x-ray, and Auger electron spectroscopy. Comparisons are made between the calculated and measured electronic densities of states, and the reactions of the surfaces with O2, H2, and CO gases are studied. The effects of heat treatment on surface segregation are also reported. Journal of Applied Physics is copyrighted by The American Institute of Physics.
Magnetic Properties Of Rare-Earth Transition-Metal Borides, S.H. Aly, E. Singleton, George C. Hadjipanayis, David J. Sellmyer, Z.R. Zhao
Magnetic Properties Of Rare-Earth Transition-Metal Borides, S.H. Aly, E. Singleton, George C. Hadjipanayis, David J. Sellmyer, Z.R. Zhao
David Sellmyer Publications
The magnetic and structural properties of quaternary RCo4-xFexB alloys with R=Nd, Sm, Er have been examined with magnetometry and x-ray diffraction. The CeCo4B-type phase is found for all x in Er, for x≤3 in Sm, and for x=0, 1, and 2 in Nd. Maximum coercivities have been obtained in a crystallized SmFe2Co2B sample with Hc>17 kOe at room temperature.
Magnetic Properties, Anisotropy, And Microstructure Of Sputtered Rare-Earth Iron Multilayers, Z.S. Shan, S. Nafis, K.D. Aylesworth, David J. Sellmyer
Magnetic Properties, Anisotropy, And Microstructure Of Sputtered Rare-Earth Iron Multilayers, Z.S. Shan, S. Nafis, K.D. Aylesworth, David J. Sellmyer
David Sellmyer Publications
A study of compositionally modulated magnetic films of the form Fe/RE, particularly for RE=Nd and Dy, has been performed by vibrating sample magnetometry, ac susceptibility and x-ray diffraction. The relationship between the magnetic properties and the layer thickness was studied systematically for X-Å Fe/Y-Å Dy, as the layer thicknesses X and Y were varied from 1.8 to 20 Å. The ranges of layer thicknesses required for perpendicular anisotropy were determined. The interface and volume anisotropy energies were estimated for X-Å Fe/Y-Å Nd and the differences in the magnetic properties between X-Å Fe/7-Å Dy and X-Å Fe/7-Å …
Ellipsometric And Magneto-Optic Properties Of Sputtered Dysprosium-Iron Multilayers, Thomas E. Tiwald, John A. Woollam, David J. Sellmyer
Ellipsometric And Magneto-Optic Properties Of Sputtered Dysprosium-Iron Multilayers, Thomas E. Tiwald, John A. Woollam, David J. Sellmyer
David Sellmyer Publications
Ellipsometric and magneto-optical properties of Dy (3.5 Å thick) and Fe (2.5–12.5 Å thick) multilayers were investigated over the spectral range from 3000 to 8000 Å in magnetic fields to 0.21 T. In this range of layer thickness the magnetic anisotropy is vertical. Kerr rotations, were found to be weakly spectrally dependent, and as large as 0.06°. The magnetically driven change of ellipticity of reflected light was as large as 0.13, depending on sample and wavelength. Ellipsometric analysis of layer thickness was performed assuming a multilayer geometry. In addition, the optical constants were determined assuming the multilayer was a homogeneous …
Magnetic Properties Of Rapidly Quenched And Annealed Fe10Rti And Related Alloys, Z.R. Zhao, Y.G. Ren, K.D. Aylesworth, David J. Sellmyer, E. Singleton, J. Strzeszewski, George C. Hadjipanayis
Magnetic Properties Of Rapidly Quenched And Annealed Fe10Rti And Related Alloys, Z.R. Zhao, Y.G. Ren, K.D. Aylesworth, David J. Sellmyer, E. Singleton, J. Strzeszewski, George C. Hadjipanayis
David Sellmyer Publications
Magnetic measurements are reported for iron-rich ternary alloys with the following compositions: Fe10NdxDy1-xTi (0≤x≤1), Fe10SmM (M=Ti, V, and Mo), and Fe10RV (R=Y, Gd, and Dy). The samples were prepared by splat cooling or melt spinning and selected samples were heat treated. The results of x-ray diffraction, electron microscopy, and thermomagnetic measurements on the Fe10NdxDy1-xTi series are presented and indicate that the rapidly quenched alloys are nearly single phase and become multiphase upon heating. Magnetic measurements on the other two series show that the substitution …
Magnetic Transitions And Phases In Random-Anisotropy Magnets, David J. Sellmyer, S. Nafis, Michael J. O'Shea
Magnetic Transitions And Phases In Random-Anisotropy Magnets, David J. Sellmyer, S. Nafis, Michael J. O'Shea
David Sellmyer Publications
The generality and universality of the Ising spin-glass-like phase transitions observed in several rare-earth, random-anisotropy magnets are discussed. Some uncertainties and practical problems in determining critical exponents are considered, and a comparison is made to insulating spin glasses and crystalline spin glasses where an apparent anisotropy-induced crossover from Heisenberg to Ising-like behavior is seen. The observation of a reentrant transition in a weak anisotropy system and its correlation with the theory of Chudnovsky, Saslow, and Serota [Phys. Rev. B 33, 251 (1986)] for the correlated spin glass is discussed. Journal of Applied Physics is copyrighted by The American Institute of …
Electronic Structure And Properties Of Sputtered Ta-Cu Films , K.D. Aylesworth, Sitaram Jaswal, M.A. Engelhardt, Z.R. Zhao, David J. Sellmyer
Electronic Structure And Properties Of Sputtered Ta-Cu Films , K.D. Aylesworth, Sitaram Jaswal, M.A. Engelhardt, Z.R. Zhao, David J. Sellmyer
David Sellmyer Publications
Films of TaxCu1-x have been produced in a co-sputtering system with dc- and rf-sputtering guns and a substrate attached to a rapidly rotating, water-cooled table. Samples were produced in the composition range 0.1≤x≤0.9. X-ray diffraction and electrical resistivity data between 4.2 and 300 K have been obtained. Diffraction measurements show that for 0.6≤x≤0.9 the samples are glassy. The room-temperature resistivities follow the Mooij correlation with a zero temperature coefficient of resistivity at a resistivity of 35 μΩ cm. The resistivity-versus-temperature data for Ta0.90Cu0.10 are compared to the extended Ziman-Faber theory …