Pure-phase BiFeO3 ceramics with enhanced electrical properties prepared by two-step sintering

A two-step sintering method was employed to fabricate BiFeO3 ceramics and the influences of sintering conditions on the structural, dielectric, ferroelectric, and piezoelectric properties were investigated. It was found that high-density and pure-phase BiFeO3 ceramics could be successfully achieved through the two-step sintering method by optimizing the sintering conditions. Furthermore, ferroelectricity and piezoelectricity were also improved by the two-step sintering method. The pure-phase BiFeO3 ceramics obtained at T1=850 °C and T2=750 °C exhibited high resistivity (1.57×106 Ω.m), large remanent polarization (Pr=0.80μC/cm2) and strong piezoelectric activity (d33=42pC/N). All these results indicated that the two-step sintering method was an effective way to improve the properties of the BiFeO3 ceramics.