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 < 30 mA/m(2) even at a high electric field of 145 kV/cm. The piezoelectric d(33) coefficients of the ceramics before and after annealing at 550 degrees C for 4 h are measured to be similar to 28 and similar to 24 pC/N, respectively. These values are higher than those of most major lead-free high-temperature piezoelectric ceramics.