Crystal structure and electrical properties of bismuth sodium titanate zirconate ceramics

• Main Authors: Rachakom A., Jaiban P., Jiansirisomboon S., Watcharapasorn A.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.ncbi.nlm.nih.gov/pubmed/3502482; http://www.scopus.com/inward/record.url?eid=2-s2.0-84856051351&partnerID=40&md5=f7f036007adcb01369d9a323d82323d7; http://cmuir.cmu.ac.th/handle/6653943832/6051
• Institution: Chiang Mai University

Lead-free bismuth sodium titanate zirconate (Bi 0.5Na 0.5Ti 1-xZr xO 3 where x = 0.20, 0.35, 0.40, 0.45, 0.60, and 0.80 mole fraction) [BNTZ] ceramics were successfully prepared using the conventional mixed-oxide method. The samples were sintered for 2 h at temperatures lower than 1,000°C. The density of the BNTZ samples was at least 95% of the theoretical values. The scanning electron microscopy micrographs showed that small grains were embedded between large grains, causing a relatively wide grain size distribution. The density and grain size increased with increasing Zr concentration. A peak shift in X-ray diffraction patterns as well as the disappearance of several hkl reflections indicated some significant crystal-structure changes in these materials. Preliminary crystal-structure analysis indicated the existence of phase transition from a rhombohedral to an orthorhombic structure. The dielectric and ferroelectric properties were also found to correlate well with the observed phase transition. © 2012 Rachakom et al.