Magnetic transformations in Ni-Zn-ferrospinel

An x-ray diffraction analysis of the thermal expansion of the crystal Ni_0.28Zn_0.72Fe_2.0O₄ in the temperature range 90–400°K was performed. It was found that the coefficient of thermal expansion (T) is anisotropic at temperatures T<260°K, and a sequence of magnetic transformations in the region of magnetic ordering was also found. The parameters of the exchange interaction for a given compound were calculated using the model of local spin deviations.Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Fizika, No. 7, pp. 23–27, July, 1986.