{"doi":"10.7567/JJAP.52.07HB03","year":"2013","issue":"7S","date_updated":"2019-05-20T12:08:02Z","abstract":[{"text":"We report the piezoelectric properties of CuO-doped hydrothermal (K,Na)NbO3 ceramics that can be applied as hard-type lead-free piezoelectric ceramics. To date, we have succeeded in synthesizing high-quality KNbO3 and NaNbO3 powders by the hydrothermal method, which is based on an ionic reaction at high temperature (around 210 $\\,^{\\circ}$C) and pressure. Increasing both the piezoelectric constant d and the mechanical quality factor (Qm) is important for resonance-type piezoelectric devices, such as ultrasonic motors and transformers. CuO doping into hydrothermal (K,Na)NbO3 ceramics was examined to realize hard-type lead-free piezoelectric ceramics. By doping with 1.2 mol \\% CuO, Qm was increased and the dielectric loss (tan δ) was decreased to 0.5\\%. The grain size was also influenced by the amount of CuO doping, which indicates that Qm is related to the density. To achieve a higher Qm value, the grain size is required to be less than 5 µm; however, excessive CuO doping leads to anomalous grain growth. Optimal piezoelectric properties were obtained for 1.2 mol \\% CuO-doped (K,Na)NbO3; k31 = 0.32, d31 = -44 pC/N, Qm (radial) = 959, and tan δ= 0.5\\%. These characteristics showed that CuO doping with hydrothermal powders is effective for obtaining hard-type ceramics, and the mechanical quality factor is more than ten times higher than that of nondoped hydrothermal (K,Na)NbO3 ceramics. Therefore, compared with the conventional solid-state method, we could succeed in obtaining hard-type ceramics by a simple and short process.","lang":"eng"}],"status":"public","date_created":"2019-05-20T12:06:04Z","user_id":"55222","volume":52,"language":[{"iso":"eng"}],"author":[{"first_name":"Yuriko","last_name":"Yokouchi","full_name":"Yokouchi, Yuriko"},{"last_name":"Maeda","first_name":"Takafumi","full_name":"Maeda, Takafumi"},{"full_name":"Bornmann, Peter","last_name":"Bornmann","first_name":"Peter"},{"id":"210","full_name":"Hemsel, Tobias","first_name":"Tobias","last_name":"Hemsel"},{"last_name":"Morita","first_name":"Takeshi","full_name":"Morita, Takeshi"}],"title":"Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders","intvolume":"        52","type":"journal_article","citation":{"ama":"Yokouchi Y, Maeda T, Bornmann P, Hemsel T, Morita T. Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders. <i>Japanese Journal of Applied Physics</i>. 2013;52(7S). doi:<a href=\"https://doi.org/10.7567/JJAP.52.07HB03\">10.7567/JJAP.52.07HB03</a>","chicago":"Yokouchi, Yuriko, Takafumi Maeda, Peter Bornmann, Tobias Hemsel, and Takeshi Morita. “Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders.” <i>Japanese Journal of Applied Physics</i> 52, no. 7S (2013). <a href=\"https://doi.org/10.7567/JJAP.52.07HB03\">https://doi.org/10.7567/JJAP.52.07HB03</a>.","apa":"Yokouchi, Y., Maeda, T., Bornmann, P., Hemsel, T., &#38; Morita, T. (2013). Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders. <i>Japanese Journal of Applied Physics</i>, <i>52</i>(7S). <a href=\"https://doi.org/10.7567/JJAP.52.07HB03\">https://doi.org/10.7567/JJAP.52.07HB03</a>","bibtex":"@article{Yokouchi_Maeda_Bornmann_Hemsel_Morita_2013, title={Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders}, volume={52}, DOI={<a href=\"https://doi.org/10.7567/JJAP.52.07HB03\">10.7567/JJAP.52.07HB03</a>}, number={7S}, journal={Japanese Journal of Applied Physics}, author={Yokouchi, Yuriko and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}, year={2013} }","ieee":"Y. Yokouchi, T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders,” <i>Japanese Journal of Applied Physics</i>, vol. 52, no. 7S, 2013.","mla":"Yokouchi, Yuriko, et al. “Piezoelectric Properties of CuO-Doped (K,Na)NbO3 Lead-Free Ceramics Synthesized with Hydrothermal Powders.” <i>Japanese Journal of Applied Physics</i>, vol. 52, no. 7S, 2013, doi:<a href=\"https://doi.org/10.7567/JJAP.52.07HB03\">10.7567/JJAP.52.07HB03</a>.","short":"Y. Yokouchi, T. Maeda, P. Bornmann, T. Hemsel, T. Morita, Japanese Journal of Applied Physics 52 (2013)."},"publication":"Japanese Journal of Applied Physics","department":[{"_id":"151"}],"_id":"9867"}