Dielectric properties and ac conductivities of dense single-phased BiFeO3 ceramics

Dense single-phase BiFeO3(BFO) ferroelectric ceramics, with a resistivity of ∼1012Ωcm, may be formed by sintering the 450°C-calcined coprecipitated powder at 800–850°C. The ceramics sintered at 750°C contain a second phase of Bi2O3. The conduction loss activation energies at room temperatures of −290 and 350–430°C are 0.126 and 1.26eV, respectively. The ac conductivity thermal variation suggests ∼290°C as the application limit for BFO ceramics. The loss at T<350°C is higher for low frequencies than for high frequencies. In contrast, an opposite effect is found at T>350°C.