Enhanced ferromagnetism and magnetoelectric response in quenched BiFeO 3 -based ceramics

The piezoelectric, ferromagnetism, and magnetoelectric response of BiFeO3-BaTiO3 ceramics with the compositions around the morphotropic phase boundary (MPB) of the solid solution were systematically investigated after the ceramics were quenched from a high temperature. We found the ferromagnetism of the quenched ceramics was greatly enhanced. An enhanced piezoelectric response d33 larger than 200 pC/N, which could be sustained up to 350℃, was measured. As the result of enhanced ferromagnetism and piezoelectric response, a large magnetoelectric response ~1.3 V/cm Oe was obtained near the mechanical resonance frequency of the quenched ceramics samples. Our research also showed that in addition to the ferromagnetism and piezoelectric response, the mechanical quality factor is another important parameter to achieve high magnetoelectric response because the physical effects are coupled through mechanical interaction in BiFeO3-based materials. Our work suggests that quenching is an effective approach to enhance the magnetoelectric response of BiFeO3-based materials and the materials are a class of single-phase multiferroic materials with high magnetoelectric response.