鈮酸鈉鉀((NayK1-y)NbO3)是一種具有取代含鉛壓電陶瓷潛力的材料；因為它的高機電耦合係數和高轉相溫度，所以被廣泛地研究。本文中，以常用的氧化物混合法製備掺雜鈮酸銅CuNb2O6 (CN) 0~4 mol% 之非含鉛鈮酸鈉鉀((Na0.5K0.5)NbO3)陶瓷。以X光繞射、掃瞄式電子顯微鏡加以分析，並研究介電、壓電與鐵電特性。根據結果顯示，鈮酸銅能有效防止陶瓷體水解與改善其電特性。此外，掺雜量1莫耳濃度的鈮酸銅之鈮酸鈉鉀在適當的燒結溫度可以有效改善陶瓷的密度和電特性。
鈮酸鈉鉀掺雜量1莫耳濃度的鈮酸銅於燒結溫度1075 °C時有相當好的壓電特性，其壓電特性 kp = 40%，kt = 45%，以及 k33 = 57%，尤其鈮酸銅掺雜後的鈮酸鈉鉀之機械品質因素達1933，相當的高，很適合製作功率元件。因此在本論文的後半部我們以鈮酸銅掺雜之鈮酸鈉鉀成功的製所出非含鉛之壓電變壓器及制動器，並測量其特性。而此以鈮酸鈉鉀為主體之非含鉛壓電變壓器之升降壓效率階可超過90%，為了分析此壓電片的特性，我們以其等效電電路圖，利用MATLAB軟體，模擬壓電變壓器的升降壓特性以及效率圖。而模擬結果與實驗結果相符。在最佳負載為20kΩ時有最佳效率95.7%。最後，我們以此無鉛壓電變壓器成功的驅動8W的T5日光燈管。

Sodium potassium niobate ((NaxK1-x)NbO3, NKN) ceramic is an attractive material replacing Pb-based piezoelectric ceramics. It has been thoroughly investigated due to its high k2 and high phase transition temperature. Lead-free (Na0.5K0.5)NbO3 ceramics doped with CuNb2O6 (CN) (0-4 mol%) have been prepared by the conventional mixed oxide method in this research. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The dielectric, piezoelectric and ferroelectric properties are also investigated. Our results show that the addition of CuNb2O6 (CN) is very effective in preventing the deliquescence and in improving the electric properties. Finally, we have focused on the preparation of 1 mol% CN doped NKN ceramics at different sintering temperatures, and systematically investigated their properties.
Lead-free (Na0.5K0.5)NbO3 ceramics doped with 1 mol% CuNb2¬O6 ceramics were prepared using the conventional mixed oxide method at a sintering temperature of 1075 °C. NKN-1CN ceramics sintered at 1075 °C exhibit excellent ‘hard’ piezoelectric properties of kp = 40%, kt = 45%, and k33 = 57%, with ferroelectric property Ec = 23 kV/cm. The mechanical quality factor (Qm) is extraordinarily high (1933) and the temperature stability is excellent (TCF = -154 ppm/ °C). The piezoelectric transformer was simplified as an equivalent circuit and analyzed using MATLAB; the results matched those of our experiment. An efficiency of 95.7 % was achieved for the NKN-01CN piezoelectric transformer with load resistance of 20 kΩ. An 8W T5 fluorescent lamp was successfully driven by the NKN-01CN piezoelectric transformer.

References

[1] S. L. Swartz, "Topics in electronic ceramics," Electrical Insulation, IEEE Transactions on, vol. 25, pp. 935-987, 1990.
[2] A.-F. Boukari, J.-C. Carmona, G. Moraru, F. Malburet, A. Chaaba, and M. Douimi, "Piezo-actuators modeling for smart applications," Mechatronics, vol. 21, pp. 339-349, 2011.
[3] Z. Yang, X. Chao, R. Zhang, Y. Chang, and Y. Chen, "Fabrication and electrical characteristics of piezoelectric PMN–PZN–PZT ceramic transformers," Materials Science and Engineering: B, vol. 138, pp. 277-283, 2007.
[4] C.-W. Ahn, H.-C. Song, S. Nahm, S. Priya, S.-H. Park, K. Uchino, H.-G. Lee, and H.-J. Lee, "Effect of ZnO and CuO on the Sintering Temperature and Piezoelectric Properties of a Hard Piezoelectric Ceramic," Journal of the American Ceramic Society, vol. 89, pp. 921-925, 2006.
[5] B. Jaffe, W. R. Cook, and H. Jaffe, Piezoelectric ceramics vol. 1: Academic press London, 1971.
[6] T. Takenaka, T. Gotoh, S. Mutoh, and T. Sasaki, "A new series of bismuth layer-structured ferroelectrics," Japanese Journal of Applied Physics, vol. 34, pp. 5384-5388, 1995.
[7] M. Hirose, T. Suzuki, H. Oka, K. Itakura, Y. Miyauchi, and T. Tsukada, "Piezoelectric properties of SrBi4Ti4O15-based ceramics," Japanese Journal of Applied Physics, vol. 38, p. 5561, 1999.
[8] Y. R. Zhang, J. F. Li, B. P. Zhang, and C. E. Peng, "Piezoelectric and ferroelectric properties of Bi-compensated (BiNa) TiO–(BiK) TiO lead-free piezoelectric ceramics," Journal of Applied Physics, vol. 103, p. 074109, 2008.
[9] H. E. Mgbemere, R. P. Herber, and G. A. Schneider, "Effect of MnO2 on the dielectric and piezoelectric properties of alkaline niobate based lead free piezoelectric ceramics," Journal of the European Ceramic Society, vol. 29, pp. 1729-1733, 2009.
[10] H. E. Mgbemere, M. Hinterstein, and G. Schneider, "Electrical and structural characterization of (KxNa1-x) NbO3 ceramics modified with Li and Ta," Journal of Applied Crystallography, vol. 44, pp. 0-0, 2011.
[11] V. Lingwal, B. Semwal, and N. Panwar, "Dielectric properties of Na 1-x K x NbO 3 in orthorhombic phase," Bulletin of Materials Science, vol. 26, pp. 619-625, 2003.
[12] H. Birol, D. Damjanovic, and N. Setter, "Preparation and characterization of (K0.5Na0.5) NbO3 ceramics," Journal of the European Ceramic Society, vol. 26, pp. 861-866, 2006.
[13] Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, and M. Nakamura, "Lead-free piezoceramics," Nature, vol. 432, pp. 84-87, 2004.
[14] Y. Watanabe, K. Sumida, S. Yamada, S. Sago, S. Hirano, and K. Kikuta, "Effect of Mn-Doping on the Piezoelectric Properties of (K0.5Na0.5)(Nb0.67Ta0.33) O3 Lead-Free Ceramics," Jpn J Appl Phys, vol. 47, pp. 3556-3558, 2008.
[15] R. Rani, S. Sharma, R. Rai, and A. L. Kholkin, "Investigation of dielectric and electrical properties of Mn doped sodium potassium niobate ceramic system using impedance spectroscopy," Journal of Applied Physics, vol. 110, p. 104102, 2011.
[16] S. L. Yang, C. C. Tsai, Y. C. Liou, C. S. Hong, B. J. Li, and S. Y. Chu, "Investigation of CuO‐Doped NKN Ceramics with High Mechanical Quality Factor Synthesized by a B‐Site Oxide Precursor Method," Journal of the American Ceramic Society, 2011.
[17] H. Y. Park, I. T. Seo, M. K. Choi, S. Nahm, H. G. Lee, H. W. Kang, and B. H. Choi, "Microstructure and piezoelectric properties of the CuO-added (Na0. 5K0. 5)(Nb0. 97Sb0. 03) O3 lead-free piezoelectric ceramics," Journal of Applied Physics, vol. 104, pp. 034103-034103-7, 2008.
[18] D. Lin, K. Kwok, and H. L. W. Chan, "Double hysteresis loop in Cu-doped K0.5Na0.5NbO3 lead-free piezoelectric ceramics," Applied Physics Letters, vol. 90, pp. 232903-232903-3, 2007.
[19] S. J. Park, H. Y. Park, K. H. Cho, S. Nahm, H. G. Lee, D. H. Kim, and B. H. Choi, "Effect of CuO on the sintering temperature and piezoelectric properties of lead-free 0.95 (Na0.5K0.5) NbO3–0.05 CaTiO3 ceramics," Materials Research Bulletin, vol. 43, pp. 3580-3586, 2008.
[20] M. R. Yang, C. S. Hong, C. C. Tsai, and S. Y. Chu, "Effect of sintering temperature on the piezoelectric and ferroelectric characteristics of CuO doped 0.95 (Na0. 5K0. 5) NbO3-0.05 LiTaO3 ceramics," Journal of Alloys and Compounds, vol. 488, pp. 169-173, 2009.
[21] R. Jaeger and L. Egerton, "Hot Pressing of Potassium‐Sodium Niobates," Journal of the American Ceramic Society, vol. 45, pp. 209-213, 1962.
[22] R. Wang, R. Xie, T. Sekiya, and Y. Shimojo, "Fabrication and characterization of potassium-sodium niobate piezoelectric ceramics by spark-plasma-sintering method," Materials Research Bulletin, vol. 39, pp. 1709-1715, 2004.
[23] Y. Guo, K. Kakimoto, and H. Ohsato, "(Na0. 5K0. 5) NbO3-LiTaO3 lead-free piezoelectric ceramics," Materials Letters, vol. 59, pp. 241-244, 2005.
[24] S. Tashiro, H. Nagamatsu, and K. Nagata, "Sinterability and piezoelectric properties of KNbO3 ceramics after substituting Pb and Na for K," Japanese journal of applied physics, vol. 41, p. 7113, 2002.
[25] R. Wang, R. Xie, T. Sekiya, Y. Shimojo, Y. Akimune, N. Hirosaki, and M. Itoh, "Piezoelectric properties of spark-plasma-sintered (Na0.5K0.5) NbO3-PbTiO3 ceramics," Japanese journal of applied physics, vol. 41, pp. 7119-7122, 2002.
[26] S. H. Park, C. W. Ahn, S. Nahm, and J. S. Song, "Microstructure and piezoelectric properties of ZnO-added (Na0.5K0.5) NbO3 ceramics," Japanese Journal of Applied Physics, vol. 43, p. 1072, 2004.
[27] M. Kosec, V. Bobnar, M. Hrovat, J. Bernard, B. Malic, and J. Holc, "New lead-free relaxors based on the K0.5Na0.5NbO3–SrTiO3 solid solution," Journal of Materials Research, vol. 19, pp. 1849-1854, 2004.
[28] Y. Guo, K. Kakimoto, and H. Ohsato, "Structure and electrical properties of lead-free (Na0.5K0.5) NbO3-BaTiO3 ceramics," Japanese Journal of Applied Physics, vol. 43, p. 6662, 2004.
[29] Y. Guo, K. Kakimoto, and H. Ohsato, "Phase transitional behavior and piezoelectric properties of (NaK) NbO–LiNbO ceramics," Applied physics letters, vol. 85, p. 4121, 2004.
[30] B. Malic, J. Bernard, J. Holc, D. Jenko, and M. Kosec, "Alkaline-earth doping in (K, Na) NbO3 based piezoceramics," Journal of the European Ceramic Society, vol. 25, pp. 2707-2711, 2005.
[31] C. Rosen, "Ceramic transformer and filters," Proc. Electronic Components Symp., pp. 205-211, 1956.
[32] P. Laoratana kul, A. V. Carazo, P. Bouchilloux, and K. Uchino, "Unipoled disk-type piezoelectric transformers," Japanese Journal of Applied Physics, vol. 41, p. 1446, 2002.
[33] K. T. Chang, H. C. Chiang, and K. S. Lyu, "Effects of electrode layouts on voltage gain characteristics for ring-shaped piezoelectric transformers," Sensors and Actuators A: Physical, vol. 141, pp. 166-172, 2008.
[34] L. Li, N. Zhang, C. Bai, X. Chu, and Z. Gui, "Multilayer piezoelectric ceramic transformer with low temperature sintering," Journal of Materials Science, vol. 41, pp. 155-161, 2006.
[35] W. Känzig, "Ferroelectrics and Antiferroeletrics," Solid State Physics, vol. 4, pp. 1-197, 1957.
[36] D. Dye, "The piezo-electric quartz resonator and its equivalent electrical circuit," Proceedings of the Physical Society of London, vol. 38, p. 399, 1925.
[37] S. Butterworth, "On electrically-maintained vibrations," Proceedings of the Physical Society of London, vol. 27, p. 410, 1914.
[38] K. S. V. Dyke, "The Piezoelectric Quartz Resonator."
[39] A. Meitzler, "IEEE standard on piezoelectricity," Society, 1988.
[40] M. Matsubara, T. Yamaguchi, W. Sakamoto, K. Kikuta, T. Yogo, and S. Hirano, "Processing and Piezoelectric Properties of Lead‐Free (K,Na)(Nb,Ta)O3 Ceramics," Journal of the American Ceramic Society, vol. 88, pp. 1190-1196, 2005.
[41] M. Matsubara, K. Kikuta, and S. Hirano, "Piezoelectric properties of (K0.5Na0.5)(Nb1-xTax) O3-K5.4CuTa10O29 ceramics," Journal of Applied Physics, vol. 97, pp. 114105-114105-7, 2005.
[42] D. Lin, K. Kwok, and H. L. W. Chan, "Piezoelectric properties and hardening behavior of KCuTaO-doped KNaNbO ceramics," Journal of Applied Physics, vol. 103, p. 064105, 2008.
[43] E. Li, H. Kakemoto, S. Wada, and T. Tsurumi, "Influence of CuO on the Structure and Piezoelectric Properties of the Alkaline Niobate‐Based Lead‐Free Ceramics," Journal of the American Ceramic Society, vol. 90, pp. 1787-1791, 2007.
[44] K. Uchino, Ferroelectric devices vol. 16: CRC, 2000.
[45] G. H. Haertling, "Ferroelectric ceramics: history and technology," Journal of the American Ceramic Society, vol. 82, pp. 797-818, 1999.
[46] S. T. Ho, "Modeling of a Disk-Type Piezoelectric Transformer," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 54, pp. 2110-2119, 2007.
[47] C. Lin, "Design and analysis of piezoelectric transformer converters," the Virginia Polytechnic Institute and State University, 1997.
[48] R. L. Lin, "Piezoelectric transformer characterization and application of electronic ballast," Virginia Polytechnic Institute and State University, 2001.
[49] Z. Yang, X. Chao, C. Kang, and R. Zhang, "Low temperature sintering and properties of piezoelectric PZT-PFW-PMN ceramics with YMnO3 addition," Materials Research Bulletin, vol. 43, pp. 38-44, 2008.
[50] C. B. Sawyer and C. Tower, "Rochelle salt as a dielectric," Physical Review, vol. 35, p. 269, 1930.
[51] K. Kakimoto, K. Akao, Y. Guo, and H. Ohsato, "Raman scattering study of piezoelectric (Na0.5K0.5)NbO3-LiNbO3 ceramics," Japanese Journal of Applied Physics, vol. 44, p. 7064, 2005.
[52] M. Kosec and D. Kolar, "On activated sintering and electrical properties of NaKNbO3," Materials Research Bulletin, vol. 10, pp. 335-339, 1975.
[53] J. Du, J. Hu, K. J. Tseng, C. S. Kai, and G. C. Siong, "Modeling and analysis of dual-output piezoelectric transformer operating at thickness-shear vibration mode," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 53, pp. 579-585, 2006.
[54] M. Guo, D. Lin, K. Lam, S. Wang, H. L. W. Chan, and X. Zhao, "A lead-free piezoelectric transformer in radial vibration modes," Review of scientific instruments, vol. 78, pp. 035102-035102-5, 2007.
[55] S. Nakashima, T. Ninomiya, H. Ogasawara, and H. Kakehashi, "Piezoelectric-transformer inverter with maximum-efficiency tracking and dimming control," vol. 2, pp. 918-923, 2002.
[56] G. Ivensky, I. Zafrany, and S. Ben-Yaakov, "Generic operational characteristics of piezoelectric transformers," Power Electronics, IEEE Transactions on, vol. 17, pp. 1049-1057, 2002.
[57] J. Salazar, A. Turo, J. A. Chavez, J. A. Ortega, and M. J. Garcia, "High-power high-resolution pulser for air-coupled ultrasonic NDE applications," Instrumentation and Measurement, IEEE Transactions on, vol. 52, pp. 1792-1798, 2003.
[58] E. Moreno, G. Gonzalez, L. Leija, O. Rodriguez, M. Castillo, and M. Fuentes, "Performance analysis of ultrasono-therapy transducer with contact detection," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 50, pp. 743-747, 2003.
[59] N. B. Smith, S. Lee, E. Maione, R. B. Roy, S. McElligott, and K. K. Shung, "Ultrasound-mediated transdermal transport of insulin in vitro through human skin using novel transducer designs," Ultrasound in medicine & biology, vol. 29, pp. 311-317, 2003.
[60] E. Maione, K. K. Shung, R. J. Meyer Jr, J. W. Hughes, R. E. Newnham, and N. B. Smith, "Transducer design for a portable ultrasound enhanced transdermal drug-delivery system," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 49, pp. 1430-1436, 2002.
[61] S. Y. Chu and C. K. Cheng, "Doping Effects of SiO2 on the Dielectric and Piezoelectric Properties of PbTiO3-Based Ceramics and Its SAW Applications," Integrated Ferroelectrics, vol. 69, pp. 65-72, 2005.
[62] S. Y. Chu, T. Y. Chen, and W. Water, "The effects of ZnO films on surface acoustic wave properties of modified lead titanate ceramic substrates," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 52, pp. 2308-2313, 2005.
[63] S. Zhang, E. F. Alberta, R. E. Eitel, C. A. Randall, and T. R. Shrout, "Elastic, piezoelectric, and dielectric characterization of modified BiScO3-PbTiO3 ceramics," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 52, pp. 2131-2139, 2005.
[64] M. Yamamoto, Y. Sasaki, A. Ochi, T. Inoue, and S. Hamamura, "Step-down piezoelectric transformer for AC-DC converters," Japanese journal of applied physics, vol. 40, p. 3637, 2001.
[65] K. J. Lim, S. H. Kang, H. H. Kim, J. S. Lee, and S. H. Jeong, "Design and performance of miniaturized piezoelectric step-down transformer," Journal of electroceramics, vol. 13, pp. 433-442, 2004.
[66] M. Sanz, P. Alou, A. Soto, R. Prieto, J. Cobos, and J. Uceda, "Magnetic-less converter based on piezoelectric transformers for step-down DC/DC and low power application," vol. 2, pp. 615-621, 2003
[67] X. Chao, Z. Yang, G. Li, and Y. Cheng, "Fabrication and characterization of low temperature sintering PMN–PZN–PZT step-down multilayer piezoelectric transformer," Sensors and Actuators A: Physical, vol. 144, pp. 117-123, 2008.
[68] H. W. Chung, S. H. Lim, G. H. Kim, D. H. Li, E. S. Lee, B. D. Ahn, and S. Y. Lee, "Fabrication and characterization of piezoelectric Pb (Zr, Ti) O3-Pb (Mn, W, Sb, Nb) O3 step-down piezoelectric transformer," Sensors and Actuators A: Physical, vol. 128, pp. 350-354, 2006.