An X-ray study of the new spinel series Co0.55Cu0.45Cr2S4-ySey

Abstract

The new spinel series Co0.55Cu0.45Cr2S4-ySey (for y=0.0, 0.5, 0.8, 1.0, 1.2, 1.3, 1.4 and 1.5) has been obtained. The technology and the results of the X-ray study of this spinel series are described. For y=0.0, 0.8 and 1.5 the temperature dependence of the lattice parameter a, the anion parameter u, the X-ray Debye temperature Theta M, the spontaneous magnetostriction omega m, the bulk modulus K as well as the Born index n of the repulsive energy and the lattice energy U are presented. The distances between the cations (in both tetrahedral and octahedral positions) and the anions are also presented. It turns out that for 1 degrees between anions and cations in tetrahedral positions the covalent bond dominates with a small contribution of the ionic bond in the case of y=1.5, and for 2 degrees between anions and cations in octahedral positions the ionic bond dominates with a small contribution of the covalent bond in the case of y=1.5.