Effects of BiMO3 on dielectric, ferroelectric, and piezoelectric properties of perovskite lead‐free piezoelectric BaTiO3–(Bi0.5Na0.5)TiO3 ceramics

• Published in: International journal of applied ceramic technology Vol. 14; no. 4; pp. 583 - 592
• Main Authors: Chaiyo, Nopsiri, Muanghlua, Rangson, Vittayakorn, Wanwilai, Vittayakorn, Naratip
• Format: Journal Article
• Language: English
• Published: Malden Wiley Subscription Services, Inc 01-07-2017
• Subjects: barium titanate; Barium titanates; bismuth sodium titanate; Coercivity; Dielectric properties; Diffraction patterns; Ferroelectric materials; Lead free; Perovskite structure; Phase transitions; piezoelectric ceramic; Piezoelectric ceramics; Piezoelectricity; Polarization; Transition temperature; X-ray diffraction; X-rays
• ISSN: 1546-542X; 1744-7402
• DOI: 10.1111/ijac.12688

New lead‐free piezoelectric ceramics of 0.9BaTiO3–(0.1−x)(Bi0.5Na0.5)TiO3–xBiMO3, M=Al and Ga, where x=0.00‐0.10, were fabricated by the solid‐state reaction technique. The effect of BiMO3 contents on the perovskite structure, phase transition, and dielectric, ferroelectric, and piezoelectric properties was investigated. X‐ray diffraction patterns showed that the ceramics exhibit a monophasic perovskite phase up to x=0.06, suggesting stabilized perovskite structures with B‐site aliovalent substitutions. Compositional‐dependent phase transitions were observed from tetragonal to pseudo‐cubic phase with increasing BiMO3 amounts. Al3+ ions were found to stabilize the transition temperature of the ceramics, while significantly decreasing transition temperature, and a change in the dielectric peak were found with an increasing amount of Ga3+. Regarding Al3+ substitution, the remanent polarization (Pr) values were found to decrease slightly with the Al3+ amount. With regard to Ga3+ substitution, Pr values decreased with the Ga3+ amount up to 0.06 and then increased slightly. The ceramics became softer with a higher degree of substitution according to the lower coercive field (Ec), when compared with 0.9BaTiO3–0.1(Bi0.5Na0.5)TiO3 ceramics. Ceramics with a lower degree of substitution and tetragonal phase showed butterfly strain loops that correlated with normal ferroelectric behavior.