Composition-Dependent Microstructures and Properties of La-, Zn-, and Cr-Modified 0.675BiFeO3-0.325BaTiO3 Ceramics

• Published in: Journal of the American Ceramic Society 2016-09, Vol.99 (9), p.2989-2994
• Main Authors: Zhang, Lin-Yu, Zhang, Ji, Chang, Yun-Fei, Yuan, Guo-Liang, Yang, Bin, Zhang, Shan-Tao
• Format: Article
• Language: English
• Subjects: Ceramics; Dielectric properties; lead-free ceramics; Microstructure; multiferroics
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.14314

Pure and 1.0 mol% La2O3, ZnO, and Cr2O3‐modified 0.675BiFeO3–0.325BaTiO3 (BF–BT) multiferroic ceramics were prepared and comparatively investigated. For pure and La‐, Zn‐, and Cr‐modified BF–BT, the average grain size is 415, 325, 580, and 395 nm, and the maximum dielectric constant temperature is 460°C, 430°C, 465°C, and 445°C, respectively. All additives weaken the ferroelectricity slightly. Zn‐ and Cr‐modifications dramatically enhance the room‐temperature magnetic properties, whereas La‐modification has almost no effect on magnetic property. Especially, the Cr‐modified BF–BT ceramics show switchable polarization and magnetization of 4.9 μC/cm2 and 0.27 emu/g at room temperature, the magnetoelectric coupling is confirmed by the magnetization‐magnetic field curves measured on ceramics before and after electric poling. The mechanism responsible for the different effects of additive on microstructures and properties are discussed based on additive‐induced point defect and second phase as well as diffusion‐induced substitution. These results not only provide a promising room‐temperature multiferroic material candidate, but also are helpful to design new multiferroic materials with enhanced properties.