Microstructures and magnetic and electric properties of low-temperature sintering Mn–Zn ferrites without and with addition of lithium borosilicate glass

Abstract

Highly sinterable Mn–Zn ferrite powder consisting of submicrometer-size particles (∼0.18 μm) with structural distortion has been prepared by grinding a coprecipitated powder with a media agitation mill. Dense pure Mn–Zn ferrites (>98% of theoretical) can be fabricated by heating at 900°C in a nitrogen atmosphere. They show magnetic and electric properties in which their permeability μ and electric resistivity ρ are 520–635 and 0.8–1.6 Ω m, respectively. These properties have been further improved by adding small amounts of lithium borosilicate glass; especially, high values of μ=1015 and ρ=474 Ω m are achieved in ferrites (900°C/12 h) with 0.1 wt% glass addition. The microstructures consist of large grains (∼35 μm) with high resistive layers at grain boundaries.