Phase transition, piezoelectric, and multiferroic properties of La(Co0.5Mn0.5)O3-modified BiFeO3-BaTiO3 lead-free ceramics

摘要

(0.75-x)BiFeO3-0.25BaTiO3-xLa(Co0.5Mn0.5)O3+1mol% MnO2 lead-free ceramics (x=0-0.10) were synthesized by a conventional solid-state reaction route and the effects of La(Co0.5Mn0.5)O3 on phase transition, piezoelectric, ferroelectric, and multiferroic properties of the ceramics were investigated. The ceramics can be well sintered at 960°C for 2h. After the addition of La(Co0.5Mn0.5)O3, the crystal structure of the ceramics is transformed from rhombohedral (space group R3c) to orthorhombic symmetry (space group Amm2), and the morphotropic phase boundary (MPB) of rhombohedral and orthorhombic phases is formed at x=0.01-0.03. The dielectric peak of the ceramics was found to become diffusive with increasing x. The ceramics with x=0-0.03 possess strong piezoelectricity with d33 of 95-108pCN-1, strong ferroelectricity with Pr of 2.2-18.1μCcm-2, considerable magnetoelectric coefficient of 372-672mV/cmOe, and high Curie temperature of 523-659°C, showing potential applications in multiferroic devices.