MAGNETIZATION STUDIES ON ALUMINUM AND CHROMIUM SUBSTITUTED NI-ZN FERRITES

The thermal variations of remanence ratio R and coercive field H-c rev eal that the compositions of Ni0.7Zn0.3Alx/CrxFe2-xO4 contain predomin ently multidomain (MD) grains. With the substitution of Al3+/Cr3+, the magnetic moment and R decrease. The decreasing behaviour is explained on the basis of exchange interaction and the effect of the anisotropy constant K-1. Both of these parameters decrease with the increase in the anisotropy constant K-1. The variation of n(B)(77 K) with Al3+/Cr3 + substitution suggests that canted spins occur in the system. The com positions of Ni0.7Zn0.3Alx/CrxFe2-xO4 ferrites were prepared by the st andard ceramic process using a computer controlled furnace. (C) 1998 E lsevier Science B.V. All rights reserved.