Abstract
Composite materials with mixed spinel nickel ferrite-barium titanate as co-existing phases have been synthesized using a conventional glass-ceramics route over a certain composition of the BaO-NiO-TiO2-Fe2O3 system. The crystallographic phases present in the composition synthesized were mainly BaTiO3 and NiFe2O3 using 2% boric acid flux while varieties of phases as NiFe2O4, Ba1.12Ti8O16, BaTi4O9 and Ni-3(BO3)(2) were observed using higher content of flux. Magnetic measurement of glasses crystallized at various time and temperature show that a ferromagnetic behavior is present that vary greatly as the flux content varies from 2% to 10%. A specific induction B-s = 7.6 emu/g and a permeability of 4809 at applied field 5000 Oe was reached by crystallizing the parent material at 900 degrees C for 4 h. The variation of the magnetic properties of the composite materials as a function of added flux, particle sizes and microstructure of the samples were investigated. (c) 2006 Elsevier B.V. All rights reserved.