Enhanced ferroelectric, magnetic and magnetoelectric properties of multiferroic BiFeO3-BaTiO3-LaFeO3 ceramics

摘要

A lead free multiferroic ceramic 0.7BiFeO(3)-0.3BaTiO(3) showed strong ferroelectric and piezoelectric properties, but weak magnetic and magnetoelectric properties. We herein expected that the electrical and magnetic properties of 0.7BiFeO(3)-0.3BaTiO(3) ceramics could be enhanced by introducing LaFeO3. (0.7-x) BiFeO3-0.3BaTiO(3)-xLaFeO(3) (x = 0-0.2) were synthesized by solid-state reaction. All the ceramics formed a perovskite structure, and a morphotropic phase boundary (MPB) between rhombohedral and orthorhombic phases formed at x = 0.025. The ceramics with MPB composition had high unipolar strain (S-max = 0.14%), piezoelectricity (d(33) = 223 pC/N, d(33) * = 350 pm/V), ferroelectricity (P-r = 25.67 mC/cm(2)) and magnetoelectricity (a(ME) = 466.6 mV/cm.Oe), which can be attributed to addition of La ions. The improved phase angle also demonstrated augmentation of ferroelectricity on the microscopic view. The ferromagnetism was evidently improved after LaFeO3 doping, and the remanent magnetization M-r increased from 0.0207 to 0.0622 emu/g with rising x from 0 to 0.075. In conclusion, with strong magnetoelectric properties, the prepared ceramics may be applicable as promising lead-free multiferroic ceramic materials for novel electronic devices.