Neutron diffraction study of chromium substituted nickel ferrite

Neutron diffraction study has been carried out to determine lattice parameter (a), oxygen positional parameter (u) and cation distribution in NiCrxFe2-xO4 system. The magnetic moment (n(B)) values measured from hysteresis and from neutron diffraction study agree with each other. However, these are lower than the theoretical values computed from Neel's colinear model. The Gilleo's model is adopted to explain the experimental results. The T(c)s calculated by this model and those measured from a.c. susceptibility agree well up to x < 0.8 and differ for higher content of x greater than or equal to 0.8. The results show that spinel with x < 0.8 have Neel type magnetic order while for x greater than or equal to 0.8 the magnetic order is not of Neel type. Copyright (C) 1996 Elsevier Science Ltd