Heterovalent substitution of group IV and V diamagnetic ions in the ferromagnetic spinel CuCr2S4

Heterovalent substitution of As5+, Sb5+, V5+, and Sn4+ diamagnetic ions in CuCT2S4 was studied. The results show that, similar to other 3d(10) diamagn etic ions, the As5+ ions occupy only tetrahedral interstices in the close p acking of sulfur ions, while the Sb5+ and Sn4+ 4d(10) ions, as well as the Sc3+, Ti4+, and V5+ 3d(0) ions occupy only octahedral sites. A new compound of composition Cu(3)ASCr(8)S(16) was synthesized and characterized. It cry stallizes in an orthorhombic (sp, gr. Pmm2) spinel-derived structure contai ning ordered Cu and As ions in tetrahedral sites (a = 13.942 +/- 0.004 Angs trom, b = 6.878 +/- 0.002 Angstrom, c = 19.692 +/- 0.006 Angstrom, Z = 4, V = 1888.43 +/- 0.92 Angstrom(3)). The CuCr1.5Sb0.5S4 spinel phase is found to crystallize in sp. gr. Fd3m (a = 10.009 +/- 0.002 Angstrom, u = 0.3815 /- 0.0004 Angstrom) with partial ordering on octahedral sites.