Crystal structure and magnetic properties of titanium-based CuTi2−xMxS4 and CuCr2−xTixSe4 chalcospinels

Abstract

CuTi2−xM xS4 (M =Fe, Mn, Co; x =0.3, 0.5) and CuCr2−xTixSe4 (x =0.3, 0.5, 0.7) chalcospinels were synthesized by conventional solid-state reactions. Their crystal structures were determined by single-crystal X-ray diffraction. All of the phases crystallized in cubic spinel-type structures (space group, View the MathML source). For all of the chalcospinel compounds, the edge-length distortion parameter (ELD) indicated that the most distorted polyhedron was Q[(Ti,M)3Cu], which displayed an ~8% distortion from an ideal tetrahedron structure (Q=S or Se).

The Mn-based thiospinel CuMn0.3Ti1.7S4 is paramagnetic, whereas the Fe-based thiospinels (CuTi2−xFexS4; x=0.3 and 0.7) are strongly antiferromagnetic due to their spin-glass states. The magnetic susceptibility measurements indicated ferromagnetic behavior for the selenospinels (CuCr2−xTixSe4; x=0.3, 0.5 and 0.7).