Effect of Te-substitution on magnetic properties of Cr2Se3-yTey (0<=y<=0.15)

The magnetic susceptibility chi and the lattice parameters as a function of temperature T for Cr2Se3-yTey (0 less than or equal to y less than or equal to 0.15) with the rhombohedral-type structure have been measured. In the samples with y = 0.01 and 0.02, chi(T) shows the sharp change around a magnetic transition temperature T-s, which is similar to that observed in Cr2Se3. The spin-glass-like behavior was observed in the samples with y = 0.05 to 0.15 at lower temperatures below a temperature T-m. Above T-s and T-m. the inverse of chi(T) for the samples with 0.01 less than or equal to y less than or equal to 0.15 exhibit a ferrimagnetic like behavior. Anisotropic thermal expansion in lattice parameters for Cr2Se2.9Te0.1 was observed around T-m. The antiferromagnetic stability and the origin of the spin-glass-like behavior are qualitatively discussed from a viewpoint of the Te-substitution effect on the magnetic exchange interactions and the local atomic environments.