An X-ray diffraction study of magnetostriction in Zn_1−xCu_xCr₂Se₄ (0·2<x<1·0)

The temperature dependence of the lattice parameter a of the powder samples of the mixed spinels Zn_{1− x}Cu_xCr₂Se₄ was measured in the temperature range 100–570 K by the X-ray powder diffraction technique. The temperature dependence of the magnetostriction was observed from these results. For x = 1.0, 0.9, 0.8, 0.3 and 0.2 the spontaneous magnetostriction ω turned out to be positive and dependent on temperature. Based on the molecular field approximation the pressure coefficients of the Curie temperature dT_c/d_p were estimated.