Crystal structure and magnetic properties of U-Os intermetallic compounds
作者:S.A.M. Mentink、G.J. Nieuwenhuys、J.A. Mydosh
DOI:10.1016/0304-8853(92)90990-6
日期:1992.2
Abstract We have investigated the structural and physical properties of the uranium/osmium intermetallics U 3 Os, U 2 Os and UOs 2 . The U-rich compounds crystallize in structures of low symmetry with small interatomic distances. Therefore they show band-like magnetic behavior. In contrast cubic UOs 2 , crystallizing in the MgCu 2 - (Laves phase-)structure with a inter-uranium distance just below the “Hill
摘要 我们研究了铀/锇金属间化合物U 3 Os、U 2 Os 和UOs 2 的结构和物理性质。富含 U 的化合物以低对称性和小原子间距离的结构结晶。因此,它们表现出带状磁性。相比之下,立方 UOs 2 在 MgCu 2 -(Laves 相-)结构中结晶,铀间距离正好低于局部力矩形成的“希尔极限”,在 TN = 41.2 K 以下反铁磁有序。我们将这些特性与各自的晶体结构,并与其他锕系/过渡金属化合物进行比较。
Magnetic, Transport and Thermal Properties of Itinerant Magnetic U-<i>T</i>(<i>T</i>=Os, Ru and Rh) Systems
The specific heat, magnetic susceptibility and electrical resistivity of uranium-transition-metal binary U-T(T=Os, Ru and Rh) and pseudo-binary URh1-xTx(T=Os and Ru) systems are presented. These systems are found to be paramagnets except URh. The electronic specific heat coefficient gamma, namely 5f density of states at the Fermi level, increases with the valence d-electron number in order of U-Os, U-Ru and U-Rh systems. URh is perceived to be an itinerant ferromagnet (T(C) = 55 K) because of the small magnetic entropy associated with the ferromagnetic transition and the small spontaneous magnetic moment at 4.2 K. Substitution of Os and Ru for Rh in URh strongly suppresses the ferromagnetic transition, which fact is qualitatively understood within the framework of the itinerant electron theory.