Effects Of SiO2 content and solution pH in raw materials on Ni-Zn ferrite magnetic properties

A series of (Ni0.5Zn0.5Fe2O4)(100-x)(SiO2)(x) (x = 5,10,20 wt%) nanocomposites were prepared by sol-gel auto-combustion method, to study the effects of silica content and solution pH (3, 5 and 7) on saturation magnetization (M-s), remnant magnetization (M-r), coercivity (H-c) and initial susceptibility (X-i). Increasing the SiO2 content resulted in decreases in M-s, M-r and X-i. Further, increasing the pH resulted in an increase in particle size and then increases in M-s, M-r and X-i, while the H-c decreases. From these data, it was found that composite with 5 wt% silica and pH 7 processes produced higher magnetization and lower coercivity. (C) 2004 Elsevier B.V. All rights reserved.