Magnetic properties and phase diagram of ZnxNi1-xFe2O4: High-temperature series expansions

Using mean field theory and high-temperature series expansions (HTSEs), extrapolated with the Pade approximants method, the effect of Zn doping on magnetic properties of NiFe2O4 ferrite spinel has been studied. The nearest neighbour super-exchange interactions for intra-site (J(AA), J(BB)) and inter-site (J(AB)) of the ZnxNi1-xFe2O4 ferrites spinels, in the range 0 <= x <= 1, have been computed using the probability approach, based on Mossbauer data. The paramagnetic CurieWeiss temperature theta and the Curie temperature T-C are calculated as a function of Zn concentration. The critical exponent gamma associated with magnetic susceptibility is calculated. The spin correlation functions intra-plane and inter-plane have been also computed and compared with exchange couplings. The obtained theoretical results are in good agreement with experimental ones obtained by magnetic measurements and Mossbauer spectroscopy. (C) 2010 Elsevier B.V. All rights reserved.