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Full-Text Articles in Physics
Magnetic Transitions And Scaling Behavior In Gd-Rich Glasses , M.J. O'Shea, David J. Sellmyer
Magnetic Transitions And Scaling Behavior In Gd-Rich Glasses , M.J. O'Shea, David J. Sellmyer
David Sellmyer Publications
The magnetic properties of amorphous alloys with composition GdxLa72-xGa18B10 have been investigated using ac-susceptibilty and dc-magnetization techniques in the temperature range 4.2–300 K. This system shows double-transition behavior for x≳67 and paramagnetic–spin-glass transition behavior for x<67. Time-dependent magnetization effects are present in the spin-glass phase and these effects vanish in finite fields, in qualitative agreement with mean-field theory. The magnetic isotherms around both the paramagnetic-ferromagnetic and ferromagnetic–spin-glass transitions scale according to the scaling hypothesis, and these results are discussed in some detail. A magnetic phase diagram for this system is obtained from the transition temperatures determined from scaling.
Spin-Glass And Double-Transition Behavior In Gd-La Glasses, Michael J. O'Shea, David J. Sellmyer
Spin-Glass And Double-Transition Behavior In Gd-La Glasses, Michael J. O'Shea, David J. Sellmyer
David Sellmyer Publications
We report studies of high-field magnetization, field-cooled magnetization, thermoremanent magnetization, and isothermal remanent magnetization as a function of temperature in the metallic glass sytem GdxLa72-xG28 where G28=Ga18B10 for the compositions x=72, 68, 64. The first two compositions show double-transition behavior and the last one shows only a paramagnetic to spin-glass transition. The approach to saturation at intermediate fields (up to 40 kOe) is of the form 1/H1/2 as predicted by a mean field model which incorporates a small random anisotropy. The field-cooled magnetization in these samples is …
Random Magnetism In Amorphous Rare-Earth Alloys (Invited), David J. Sellmyer, S. Nafis
Random Magnetism In Amorphous Rare-Earth Alloys (Invited), David J. Sellmyer, S. Nafis
David Sellmyer Publications
Several aspects of the magnetic transitions seen in rare-earth metallic glasses are discussed, particularly with reference to recent theoretical work. These include: (a) apparent double transitions observed in Gd glasses where exchange fluctuations are important, (b) evidence for a correlated speromagnetic state recently predicted by Chudnovsky and Serota, and (c) the analysis of a Tb glass with strong random anisotropy in terms of an Ising-type spin-glass transition. Journal of Applied Physics is copyrighted by The American Institute of Physics.
Anomalous Magnetic Hysteresis In An Amorphous Nd54Co36B10 Alloy, George C. Hadjipanayis, S.H. Aly, David J. Sellmyer
Anomalous Magnetic Hysteresis In An Amorphous Nd54Co36B10 Alloy, George C. Hadjipanayis, S.H. Aly, David J. Sellmyer
David Sellmyer Publications
The hysteresis and crystallization behavior of an amorphous Nd54Co36B10 alloy have been examined over a range of temperatures. Crystallization studies show a glass transition temperature around 210 °C, two crystallization peaks at around 220 and 360 °C, and two endothermic peaks at around 530 and 600 °C, respectively. ac susceptibility measurements show an ordering temperature of 38 K for the amorphous phase. Four additional magnetic phases have been observed in the crystallized samples with ordering temperatures 17, 45, 90, and 190 K, respectively. Magnetic measurements on melt-spun ribbons reveal a coercivity of 6 kOe at …
Photoemission, Electronic Structure, And Magnetism In Vpd3, D.K. Misemer, S. Auluck, David J. Sellmyer, Sitaram Jaswal, A.J. Arko
Photoemission, Electronic Structure, And Magnetism In Vpd3, D.K. Misemer, S. Auluck, David J. Sellmyer, Sitaram Jaswal, A.J. Arko
David Sellmyer Publications
Electronic and magnetic states in the ordered compound VPd3 have been investigated with photoemission measurements and self-consistent band-structure calculations. The linear combination of muffin-tin orbitals method was used to study VPd3 in a hypothetical cubic crystal structure and the actual tetragonal crystal structure, and the calculations were performed for both paramagnetic and spin-polarized configurations. The results for the cubic structure are in agreement with earlier calculations, while the results from the tetragonal structure are in much better agreement with the photoemission and other measurements.