High‐Temperature Susceptibility of Uranium Compounds with Th₃P₄‐Type Crystal Structure

Abstract

Abstract Magnetic susceptibility measurements for six uranium compounds with P, As, Sb, Bi, Se, and Te having Th 3 P 4 ‐type crystal structure, have been performed in the temperature range 77 to 1200 °K. In the higher temperature region, the dependence of χ −1 on T is found to be curvilinear or all these compounds. The experimental results, corrected for the presence of magnetic exchange interactions, are compared with theoretical ones, obtained by taking into account the influence of the crystal field on the central U +4 ion in the tetragonal D 2d ‐symmetry. The increase of the paramagnetic moment of U +4 in U 3 X 4 compounds from 2.75 to 3.14 BM is explained by the assumption that the pseudo‐doublet is the ground state. The anisotropy of the magnetic properties of an individual U +4 ion and the relation between the paramagnetic and the ferromagnetic moment are theoretically established and found to be in accordance with the experiment.