Effect of B2O3 on the densification and magnetic properties of Li-Zn ferrite

Densification, grain growth and magnetic properties of Li-Zn ferrite (Li.30Zn4Fe2.30O4) doped with B2O3 as a sintering aid were investigated. B2O3 is a low melting point (460 degrees C) oxide and forms a liquid phase during sintering which affects the densification and grain growth of ferrites. Results showed that density and grain growth rate were sensitive to the B2O3 content and sintering temperature. At low amounts of B2O3 (< 1 wt.%), an increase in the B2O3 content increased density and grain growth rate. The highest density and the maximum magnetization were obtained for the sample containing 1.0 wt.% B2O3 which was sintered at a lower temperature (1000 degrees C) for 1.5 h, in comparison with undoped samples. Higher B2O3 contents than 1.0 wt.% caused a decrease in density of samples due to secondary phases formation and evaporation of B2O3. The sample with the highest grain size showed the highest permeability and the lowest magnetic loss. (C) 2011 Elsevier Ltd. All rights reserved.