Study on magnetic properties and structural analysis of Ni-Zn ferrite prepared through self-propagating high-temperature synthesis reaction by neutron diffractometry

The NixZn1-xFe2O4 ferrites were prepared by self-propagating high-temperature synthesis at the oxygen partial pressures of 0.5 and 5.0 MPa. Neutron diffraction revealed that the final stoichiometries of the ferrites were Ni0.38Zr0.62Fe2O4 and Ni0.33Zn0.67Fe2O4, respectively. As the oxygen pressure changed from 0.5 to 5.0 MPa, the coercive force (H-c) and residual magnetization (M-r) decreased about 55 and 30%, respectively. Whereas, the maximum magnetization (M-s), susceptibility (DeltaM/DeltaH) and curie temperature increased about 14, 65 and 2.5%, respectively. The improved magnetic properties is attributed to the increased spinel formation due to oxygen pressure during the self-propagating high temperature synthesis and different non-stoichiometric numbers of the ferrites due to the competitive reduction reaction between nickel oxide and zinc oxide. (C) 2001 Elsevier Science B.V. All rights reserved.