Bi2O3, Fe2O3, BaCO3, and TiO2 powder with purity higher than
99% were weighed and mixed by ball-milling for 24 h, in plastic
bottles with distilled water and yttria-stabilized zirconia (YSZ)
balls.After drying,the mixed powder was calcined by consecutive
heat treatments at 750 °C for 5 h and at 800 °C for 5 h