Unusual thermal behaviour of ZnCr₂Se₄ at elevated temperatures

Thermal expansion of ZnCr₂Se₄ was investigated from room temperature to 301 degrees C. Zinc chromium selenide, an antiferromagnetic spinel with a helical spin structure and of space group Fd 3m (O_h⁷), showed unusual behaviour above 340 degrees C on DTA. Thermal expansion of this compound in the temperature range 26-301 degrees C is reported in this paper. The average value of its thermal expansion coefficient in the specified temperature range is found to be 11.69*10^-6 degrees C^-1.