Magnetic Properties and Electrical Conduction of Copper-Containing Sulfo- and Selenospinels

${\mathrm{CuCr}}_{\text{1+x}}{\mathrm{Rh}}_{\text{1−x}}{\mathrm{Se}}_4$ with $\text{−1\hspace{0.17em}<\hspace{0.17em}x\hspace{0.17em}≦\hspace{0.17em}1}$ and ${\mathrm{CuCr}}_{\text{1+x}}{\mathrm{Ti}}_{\text{1−x}}{\mathrm{S}}_4$ with $\text{0\hspace{0.17em}<\hspace{0.17em}x\hspace{0.17em}≦\hspace{0.17em}1}$ show p‐type metallic conduction and are ferromagnetic, while ${\mathrm{CuCr}}_{\text{1+x}}{\mathrm{Ti}}_{\text{1−x}}{\mathrm{S}}_4$ with $\text{x<0}$ show n‐type metallic conduction and no magnetic ordering at 4°K. From the magnetic and electrical properties, which indicate that Cu is monovalent in these compounds, a model for the electronic structure of copper‐containing sulfospinels is deduced. Ferromagnetism and p‐type conduction are attributed to holes in a broad valence band, n‐type conduction to electrons in a broad conduction band. Susceptibility measurements on ${\mathrm{CuCo}}_2{\mathrm{S}}_4$ , ${\mathrm{CuTi}}_2{\mathrm{S}}_4$ , ${\mathrm{CuCoTiS}}_4$ , ${\mathrm{CuRh}}_2{\mathrm{S}}_4$ , and ${\mathrm{CuRh}}_2{\mathrm{Se}}_4$ are reported. The main contribution to the temperature‐independent susceptibility observed is attributed to the Van Vleck susceptibility of Co³⁺ or Rh³ ions in the low spin state $t_2^6$ .