High power density NaNbO3-LiTaO3 lead-free piezoelectric transformer in radial vibration modes

Sun, H.L., Lin, D.M., Lam, K.H. , Guo, M.S., Choy, S.H., Kwok, K.W. and Chan, H.L.W. (2015) High power density NaNbO3-LiTaO3 lead-free piezoelectric transformer in radial vibration modes. Smart Materials and Structures, 24(6), 065017. (doi: 10.1088/0964-1726/24/6/065017)

Abstract

In the present work, the sintering temperature was able to substantially influence the microstructure and electrical properties of the lead-free ceramic 0.88NaNbO3–0.12LiTaO3. This composition without any acceptor doping presents a high mechanical quality factor, Qm, value of 1469 and a high Curie temperature of 305 °C by optimizing the sintering temperature at 1330 °C. We applied this material to make a device of disk-shaped piezoelectric transformers with a ring–dot structure and further focused on investigating the characteristics of the piezoelectric transformers. With matching load, a maximum efficiency of 92% occurs in the fundamental mode, and the maximum voltage gains are 5.5 and 3.7 for the fundamental and third radial vibration modes, respectively. The experimental results show a maximum output power of 10.5 W with a temperature rise of 27 °C. It is noteworthy that a high output power density (as high as 32.8 W cm−3) was obtained under a maximum input voltage of 180 V, which is comparable to the performance of PZT in a piezoelectric ceramic transformer device.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lam, Dr Koko
• Authors: Sun, H.L., Lin, D.M., Lam, K.H., Guo, M.S., Choy, S.H., Kwok, K.W., and Chan, H.L.W.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Smart Materials and Structures
• Publisher: IOP Publishing
• ISSN: 0964-1726
• ISSN (Online): 1361-665X