Enhanced ferroelectricity, piezoelectricity, and ferromagnetism in Nd-modified BiFeO3-BaTiO3 lead-free ceramics

Lead-free multiferroic ceramics of 0.75Bi(1-x)Nd(x)FeO(3) -0.25BaTiO(3) + 1 mol. % MnO2 were prepared by a conventional ceramic technique and their structure, piezoelectricity, and multiferroicity were studied. The ceramics sintered at 890-990 degrees C possess a pure perovskite structure. A morphotropic phase boundary of rhombohedral and monoclinic phases is formed at x = 0.05. A small amount of Nd improves the ferroelectric and piezoelectric properties of the ceramics. The ferroelectric-paraelectric phase transition becomes gradually diffusive with x increasing. After the addition of Nd, the ferromagnetism of the ceramics is greatly enhanced by similar to 320%. The increase in sintering temperature improves significantly the ferroelectric, piezoelectric, and ferromagnetic properties of the ceramics. The ceramics with x = 0.05 sintered at 950-990 degrees C possess improved ferroelectricity, piezoelectricity, magnetism and insulation with P-r of 16.5-17.5 mu C/cm(2), d(33) of 113-121 pC/ N, M-r of 0.127-0.138 emu/g, R of similar to 5 x 10(9) Omega.cm and high T-C of 473-482 degrees C, indicating that the ceramic is a promising candidate for room-temperature multiferroic and high-temperature piezoelectric materials. (C) 2014 AIP Publishing LLC.