Dielectric, ferroelectric and magnetic properties of Bi0.78La0.08Sm0.14Fe0.85Ti0.15O3 ceramics prepared at different sintering conditions

Although BiFeO3 (BFO) has attracted great attention due to its special physical properties as a typical single phase multiferroic material, the application is limited due to the formation of impurities, defects and so forth. Herein, we report improved multiferroic properties of Bi0.78La0.08Sm0.14Fe0.85Ti0.15O3 (BLSFTO) ceramics by combination of co-doping and sintering schedule. BLSFTO multiferroic ceramics were prepared by using the conventional solid state reaction method and the effect of sintering time (2, 5, 10, 20 and 30 h) on the structural, dielectric and multiferroic properties was investigated systematically. The result indicates that stable BLSFTO phase with perovskite structure was formed for all the samples. Only some impurities such as Bi2O4 can be observed when the sintering time is longer than 20 h, indicating that the sintering time can induce structural changes in BLSFTO and too long sintering time can remarkably increase the secondary phases. In addition, the frequency dependent dielectric properties show that sintering time has distinct effect on the frequency stability and the relaxation process. The result demonstrates that the enhanced magnetization, improved dielectric and ferroelectric properties may be correlated with the structural transformation, impurities, oxygen vacancies and grain morphology