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Growth and piezoelectric properties of gallium-free langasite structure crystal Ca3NbAl3Si2O14
|Yanqing Zheng 1, Jun Xin , Kainan Xiong , Xiaoniu Tu , Haikuan Kong , Erwei Shi|
1. Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China
Piezoelectric crystals with langasite structure were broadly used in high temperature sensors in recent years. The high content of gallium made these crystals much more expensive compared than quartz. A bulk single crystal of gallium-free compound Ca3NbAl3Si2O14 (CNAS) with langasite structure was successfully grown by Czochralski technique. The CNAS was in strong growth habits with the dimensions of 10 mm in thickness, 25 mm in width and 45 mm in length. The piezoelectric properties of CNAS were forecasted by first-principle calculation. The density measure by Archimedes method is 3.28 kg/m3. High-resolution X-ray diffraction (HRXRD) results indicate that CTAS crystals are free of low-angle boundaries. The whole set of piezoelectric, elastic and dielectric tensors were tested by the resonance method. The piezoelectric constant d11 is -4.69 pC/N and d14 is 3.57 pC/N. The dielectric constant ε11 is 13.28 and ε33 is 17.7. The electromechanical coefficient k12 is 14.7% and k26 is 17.2%. The comparison of experimental and theoretical results shown that the first-principles is a good tool for searching novel piezoelectric crystals. Combined with the properties of the high resistivity under high temperature, CNAS is a good candidate for high temperature application.
Presentation: Oral at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, Topical Session 6, by Yanqing Zheng
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17
Submitted: 2013-03-26 07:51 Revised: 2013-03-26 09:46