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David Sellmyer Publications

1979

Articles 1 - 6 of 6

Full-Text Articles in Physics

Magnetic Ordering And Exchange Interactions In The Rare-Earth Gallium Compounds R Ga2, T.-H. Tsai, David J. Sellmyer Dec 1979

Magnetic Ordering And Exchange Interactions In The Rare-Earth Gallium Compounds R Ga2, T.-H. Tsai, David J. Sellmyer

David Sellmyer Publications

Magnetic ordering and indirect exchange interactions were studied in the series of hexagonal rare-earth intermetallic compounds R Ga2, where R denotes Ce, Pr, Nd, Gd, Tb, Dy, Ho, and Er. The magnetic susceptibility (χ) of polycrystalline samples was measured at low fields, from 1.5 K to about 300 K; the magnetization (M) versus applied magnetic field (H) of these polycrystalline samples and a HoGa2 single crystal was measured up to 80 kOe at low temperatures; the resistivities (ρ) of CeGa2, GdGa2, DyGa2, and HoGa2 were measured …


Magnetically Dilute Metallic Glasses. Ii. 4F Moments, G.R. Gruzalski, David J. Sellmyer Jul 1979

Magnetically Dilute Metallic Glasses. Ii. 4F Moments, G.R. Gruzalski, David J. Sellmyer

David Sellmyer Publications

Magnetic-susceptibility and high-field magnetization measurements are presented for amorphous Zr40Cu600-xMx (M denoting Gd and Tb), with x ranging from zero to ten. Effective moments of magnetic solutes were determined by fitting susceptibility data to the Curie-Weiss expression. The moments of Gd and Tb are very close to those expected for trivalent ions and the paramagnetic Weiss temperatures are positive. Saturation did not occur in any of the samples, even at 80 kOe and 1.3 K; however, the alloys containing Gd approached normalized magnetization values of unity. High-field hysteresis loops were used to obtain the …


Magnetically Dilute Metallic Glasses. I. 3D Moments, G.R. Gruzalski, David J. Sellmyer Jul 1979

Magnetically Dilute Metallic Glasses. I. 3D Moments, G.R. Gruzalski, David J. Sellmyer

David Sellmyer Publications

Magnetic-susceptibility and high-field magnetization measurements are presented for amorphous Zr40Cu50M10 (M denoting Fe, Mn) and Nb50Ni50-xFex, with x ranging from zero to about ten. Curie-Weiss fits to the susceptibility data were made to determine effective moments peff and paramagnetic Weiss temperatures, ⊖. The small values of peff suggest the presence of moment instabilities depending on local environment, and the negative ⊖ values suggest antiferromagnetic local-moment-conduction-electron interactions. The Fe alloys develop hysteresis at low temperatures indicating the presence of a magnetically ordered state. These alloys can be …


Magnetic Properties Of Iron-Doped Layer-Structure Dichalcogenides , S.J. Hillenius, R.V. Coleman, E.R. Domb, David J. Sellmyer May 1979

Magnetic Properties Of Iron-Doped Layer-Structure Dichalcogenides , S.J. Hillenius, R.V. Coleman, E.R. Domb, David J. Sellmyer

David Sellmyer Publications

Magnetic-susceptibility measurements have been made on dilute excess Fe alloys of the layer-structure crystals TaSe2, NbSe2, and TaS2. The 2H selenides show local-moment formation and obey a Curie-Weiss law in the range 300-30 K with effective moments in the range (2.5-4.5)μB. For 2H-FexTaSe2 a strong susceptibility maximum is observed at low temperature and at low fields the maximum has a cusplike shape characteristic of a "spin-glass" type transition. The temperature of the maximum scales approximately linearly with Fe concentration and reaches 13 K for x=0.10. …


Electronic Properties And Superconductivity Of Zr-Pd Glasses, G.R. Gruzalski, J.A. Gerber, David J. Sellmyer Apr 1979

Electronic Properties And Superconductivity Of Zr-Pd Glasses, G.R. Gruzalski, J.A. Gerber, David J. Sellmyer

David Sellmyer Publications

Electrical-resistivity measurements between 1.4 and 300 K and room-temperature magnetic-susceptibility measurements were performed on the metallic glasses ZrxPd1-x, for x=0.59, 0.63, 0.67, and 0.70. The samples, prepared by a modified hammer-anvil technique, exhibit negative temperature coefficients of the resistivity at temperatures from about 10 to 300 K. These data can be understood in terms of the extended Ziman theory if it is assumed that Zr and Pd contribute about 2 and 1 conduction electrons, respectively. Assuming that the magnetic susceptibility is a qualitative measure of the electronic density of states at the Fermi level, N …


Magnetic Properties Of The Rare-Earth Glasses (R65Fe35)100-XBX, J.A. Gerber, S.G. Cornelison, W.L. Burmester, David J. Sellmyer Mar 1979

Magnetic Properties Of The Rare-Earth Glasses (R65Fe35)100-XBX, J.A. Gerber, S.G. Cornelison, W.L. Burmester, David J. Sellmyer

David Sellmyer Publications

Results are reported on the magnetic properties of (R65Fe35)100-xBx glasses, where R denotes Y, Gd, and Er, and x is 10 or 20. Curie-Weiss fits were made to high temperature susceptibility data to determine average effective moments per magnetic ion and Weiss temperatures. Hysteresis loops and modified Arrott plots were used to determine the spontaneous magnetizations, coercive forces, and ordering temperatures. The effective moments and spontaneous moments are compared with those calculated on the assumption of local moments on both magnetic subnetworks, and assuming various spin structures. There is evidence for moment instabilities …