Multiferroic Features of Fe-Added BaTiO3 Ceramics Prepared by Microwave-Assisted Heat-Treatment

Abstract

The multiferroic features and secondary phases of Fe-added BaTiO3 ceramics were investigated by examining two different types of BaTiO3 nano-sized powders. Fe-doped powders were synthesized using a hydrothermal method, and Fe-coated powders were made using a sol-gel method. These powders were heat-treated by microwave sintering in a temperature range of 600-1200 degrees C. The ceramics made from powders coated with 40 wt% Fe exhibited a maximum saturated magnetization (M-s) of similar to 450 memu/g when they were heat-treated at 700 degrees C; the dielectric constant varied steadily from 200 to 1100 as the temperature was increased from 600 to 1200 degrees C. The formation of secondary phases such as BaFe12O19 and Ba2Fe2O5 during heat-treatment seems to be critically associated with the observed evolution of ferromagnetic properties in the samples. The use of microwaves during heat-treatment resulted in lowering the preparation temperature by 200-300 degrees C, compared to conventional heating methods. The product of M-s and the dielectric constant exhibited its maximum value (239,200) for the BaTiO3 ceramics prepared at 900 degrees C using microwave sintering. © 2017 by American Scientific Publishers.