Enhanced piezoelectric and pyroelectric effects in single-phase multiferroic Bi1−xNdxFeO3 (x=0–0.15) ceramics

Single-phase multiferroic Bi1−xNdxFeO3 (x=0–0.15) ceramics are polarized and their piezoelectric and pyroelectric effects are reported. The success in polarizing the ceramics originates from low electrical conductivities controlled predominantly by the Poole-Frenkel conduction mechanism. Limited internal traps due to reduced oxygen vacancies in the ceramics result in sufficiently low leakage current densities of <30mA∕m2 even at a high electric field of 145kV∕cm. The piezoelectric d33 coefficients of the ceramics before and after annealing at 550°C for 4h are measured to be ∼28 and ∼24pC∕N, respectively. These values are higher than those of most major lead-free high-temperature piezoelectric ceramics.