--- _id: '9878' abstract: - lang: eng text: (K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders. author: - first_name: G. full_name: Isobe, G. last_name: Isobe - first_name: Takafumi full_name: Maeda, Takafumi last_name: Maeda - first_name: Peter full_name: Bornmann, Peter last_name: Bornmann - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel - first_name: Takeshi full_name: Morita, Takeshi last_name: Morita citation: ama: Isobe G, Maeda T, Bornmann P, Hemsel T, Morita T. Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics. Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on. 2014;61(2):225-230. doi:10.1109/TUFFC.2014.6722608 apa: Isobe, G., Maeda, T., Bornmann, P., Hemsel, T., & Morita, T. (2014). Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics. Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions On, 61(2), 225–230. https://doi.org/10.1109/TUFFC.2014.6722608 bibtex: '@article{Isobe_Maeda_Bornmann_Hemsel_Morita_2014, title={Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics}, volume={61}, DOI={10.1109/TUFFC.2014.6722608}, number={2}, journal={Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on}, author={Isobe, G. and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}, year={2014}, pages={225–230} }' chicago: 'Isobe, G., Takafumi Maeda, Peter Bornmann, Tobias Hemsel, and Takeshi Morita. “Synthesis of Lead-Free Piezoelectric Powders by Ultrasonic-Assisted Hydrothermal Method and Properties of Sintered (K0.48Na0.52)NBO3 Ceramics.” Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions On 61, no. 2 (2014): 225–30. https://doi.org/10.1109/TUFFC.2014.6722608.' ieee: G. Isobe, T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics,” Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on, vol. 61, no. 2, pp. 225–230, 2014. mla: Isobe, G., et al. “Synthesis of Lead-Free Piezoelectric Powders by Ultrasonic-Assisted Hydrothermal Method and Properties of Sintered (K0.48Na0.52)NBO3 Ceramics.” Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions On, vol. 61, no. 2, 2014, pp. 225–30, doi:10.1109/TUFFC.2014.6722608. short: G. Isobe, T. Maeda, P. Bornmann, T. Hemsel, T. Morita, Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions On 61 (2014) 225–230. date_created: 2019-05-20T13:10:14Z date_updated: 2019-09-16T10:53:17Z department: - _id: '151' doi: 10.1109/TUFFC.2014.6722608 intvolume: ' 61' issue: '2' keyword: - Q-factor - ceramics - crystal growth from solution - particle size - piezoelectric materials - potassium compounds - powders - sintering - sodium compounds - ultrasonic effects - (K0.48Na0.52)NbO3 - KNbO3 powders - NaNbO3 powders - high-power ultrasonic irradiation - lead-free piezoelectric materials - lead-free piezoelectric powders - particle size reduction - piezoelectric properties - quality factor - sintered (K0.48Na0.52)NbO3 ceramics - sintering - ultrasonic-assisted hydrothermal method - Acoustics - Ceramics - Lead - Piezoelectric materials - Powders - Radiation effects - Transducers language: - iso: eng page: 225-230 publication: Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on publication_identifier: issn: - 0885-3010 quality_controlled: '1' status: public title: Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics type: journal_article user_id: '55222' volume: 61 year: '2014' ... --- _id: '9788' abstract: - lang: eng text: 'A hydrothermal method utilizes a crystallization process in the solution so that the pure and high-quality powders can be realized. Sintering from the hydrothermal KNbO3 and NaNbO3 powders, a high-dense lead-free piezoelectric (K,Na)NbO3 ceramics could be obtained (density: 98.8\%). Concerning about the g33 constant, high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal (K,Na)NbO3 ceramics is usable for the sensors and the energy harvesting devices. To demonstrate the (K,Na)NbO3 ceramics, a hydrophone sensor was fabricated and evaluated.' author: - first_name: Takafumi full_name: Maeda, Takafumi last_name: Maeda - first_name: Peter full_name: Bornmann, Peter last_name: Bornmann - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel - first_name: Takeshi full_name: Morita, Takeshi last_name: Morita citation: ama: 'Maeda T, Bornmann P, Hemsel T, Morita T. Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics. In: Ultrasonics Symposium (IUS), 2012 IEEE International. ; 2012:194-195. doi:10.1109/ULTSYM.2012.0048' apa: Maeda, T., Bornmann, P., Hemsel, T., & Morita, T. (2012). Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics. In Ultrasonics Symposium (IUS), 2012 IEEE International (pp. 194–195). https://doi.org/10.1109/ULTSYM.2012.0048 bibtex: '@inproceedings{Maeda_Bornmann_Hemsel_Morita_2012, title={Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics}, DOI={10.1109/ULTSYM.2012.0048}, booktitle={Ultrasonics Symposium (IUS), 2012 IEEE International}, author={Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}, year={2012}, pages={194–195} }' chicago: Maeda, Takafumi, Peter Bornmann, Tobias Hemsel, and Takeshi Morita. “Piezoelectric Applications of Hydrothermal Lead-Free (K0.48Na0.52)NbO3 Ceramics.” In Ultrasonics Symposium (IUS), 2012 IEEE International, 194–95, 2012. https://doi.org/10.1109/ULTSYM.2012.0048. ieee: T. Maeda, P. Bornmann, T. Hemsel, and T. Morita, “Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics,” in Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 194–195. mla: Maeda, Takafumi, et al. “Piezoelectric Applications of Hydrothermal Lead-Free (K0.48Na0.52)NbO3 Ceramics.” Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 194–95, doi:10.1109/ULTSYM.2012.0048. short: 'T. Maeda, P. Bornmann, T. Hemsel, T. Morita, in: Ultrasonics Symposium (IUS), 2012 IEEE International, 2012, pp. 194–195.' date_created: 2019-05-13T13:28:05Z date_updated: 2022-01-06T07:04:20Z department: - _id: '151' doi: 10.1109/ULTSYM.2012.0048 keyword: - crystallisation - hydrophones - piezoceramics - potassium compounds - powder technology - powders - sensors - sintering - sodium compounds - (K0.48Na0.52)NbO3 - KNbO3 powder - NaNbO3 powder - crystallization - energy harvesting devices - g33 constant - hydrophone sensor - hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics - hydrothermal method - piezoelectric applications - sintering - Materials - Transducers language: - iso: eng page: 194-195 publication: Ultrasonics Symposium (IUS), 2012 IEEE International publication_identifier: issn: - 1948-5719 quality_controlled: '1' status: public title: Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics type: conference user_id: '55222' year: '2012' ... --- _id: '9743' abstract: - lang: eng text: The hydrothermal method enables the production of high-quality piezoelectric materials. In this study, we propose to irradiate the reaction solutions with ultrasonic power during the hydrothermal method to obtain a shorter reaction time and a smooth film surface. A high-pressure reaction container for the ultrasonic transducer was newly developed, and the ultrasonically-assisted hydrothermal method was examined by using this container. The effect of ultrasonic assist on the synthesis of lead-zirconate-titanate (PZT) thin films and (K,Na)NbO$_{3}$ powders was verified. Thicker PZT film, thickness around 10 ${\mu}$m, could be obtained in one process, and (K,Na)NbO$_{3}$ powder was synthesized in half the previous reaction time. author: - first_name: Ryo full_name: Ageba, Ryo last_name: Ageba - first_name: Yoichi full_name: Kadota, Yoichi last_name: Kadota - first_name: Takafumi full_name: Maeda, Takafumi last_name: Maeda - first_name: Norihito full_name: Takiguchi, Norihito last_name: Takiguchi - first_name: Takeshi full_name: Morita, Takeshi last_name: Morita - first_name: Mutsuo full_name: Ishikawa, Mutsuo last_name: Ishikawa - first_name: Peter full_name: Bornmann, Peter last_name: Bornmann - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel citation: ama: Ageba R, Kadota Y, Maeda T, et al. Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis. Journal of Korean Physical Society. 2010;57(4):918-923. doi:10.3938/jkps.57.918 apa: Ageba, R., Kadota, Y., Maeda, T., Takiguchi, N., Morita, T., Ishikawa, M., … Hemsel, T. (2010). Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis. Journal of Korean Physical Society, 57(4), 918–923. https://doi.org/10.3938/jkps.57.918 bibtex: '@article{Ageba_Kadota_Maeda_Takiguchi_Morita_Ishikawa_Bornmann_Hemsel_2010, title={Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis}, volume={57}, DOI={10.3938/jkps.57.918}, number={4}, journal={Journal of Korean Physical Society}, author={Ageba, Ryo and Kadota, Yoichi and Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Bornmann, Peter and Hemsel, Tobias}, year={2010}, pages={918–923} }' chicago: 'Ageba, Ryo, Yoichi Kadota, Takafumi Maeda, Norihito Takiguchi, Takeshi Morita, Mutsuo Ishikawa, Peter Bornmann, and Tobias Hemsel. “Ultrasonically-Assisted Hydrothermal Method for Ferroelectric Material Synthesis.” Journal of Korean Physical Society 57, no. 4 (2010): 918–23. https://doi.org/10.3938/jkps.57.918.' ieee: R. Ageba et al., “Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis,” Journal of Korean Physical Society, vol. 57, no. 4, pp. 918–923, 2010. mla: Ageba, Ryo, et al. “Ultrasonically-Assisted Hydrothermal Method for Ferroelectric Material Synthesis.” Journal of Korean Physical Society, vol. 57, no. 4, 2010, pp. 918–23, doi:10.3938/jkps.57.918. short: R. Ageba, Y. Kadota, T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, P. Bornmann, T. Hemsel, Journal of Korean Physical Society 57 (2010) 918–923. date_created: 2019-05-13T09:35:33Z date_updated: 2022-01-06T07:04:19Z department: - _id: '151' doi: 10.3938/jkps.57.918 intvolume: ' 57' issue: '4' keyword: - Hydrothermal method - High-power ultrasonic - PZT thin film - Lead-free piezoelectric materials language: - iso: eng page: 918-923 publication: Journal of Korean Physical Society publication_identifier: issn: - 1948-5719 quality_controlled: '1' status: public title: Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis type: journal_article user_id: '55222' volume: 57 year: '2010' ... --- _id: '9744' abstract: - lang: eng text: Direct ultrasound irradiation is advantageous to increase the efficiency of the hydrothermal method which can be used for the production of piezoelectric thin films and lead free piezoelectric ceramics. To apply ultrasound directly to the process transducer prototypes were developed regarding the boundary conditions of the hydrothermal method. LiNbO$_{3}$ and PIC 181 were proven as feasible materials for high temperature resistant transducers ($\geq 200^\circ C$). Resistance of the transducers horn against the corrosive mineralizer was achieved by using Hastelloy C-22. The efficiency of the ultrasound assisted hydrothermal method depends on the generated sound field. Impedance and sound field measurements have shown that the sound field depends on the filling level and the position and design of the transducer. author: - first_name: Peter full_name: Bornmann, Peter last_name: Bornmann - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel - first_name: Walter full_name: Littmann, Walter last_name: Littmann - first_name: Ryo full_name: Ageba, Ryo last_name: Ageba - first_name: Yoishi full_name: Kadota, Yoishi last_name: Kadota - first_name: Takeshi full_name: Morita, Takeshi last_name: Morita citation: ama: Bornmann P, Hemsel T, Littmann W, Ageba R, Kadota Y, Morita T. Ultrasonic Transducer for the Hydrothermal Method. Journal of Korean Physical Society. 2010;57(4):1122. doi:10.3938/jkps.57.1122 apa: Bornmann, P., Hemsel, T., Littmann, W., Ageba, R., Kadota, Y., & Morita, T. (2010). Ultrasonic Transducer for the Hydrothermal Method. Journal of Korean Physical Society, 57(4), 1122. https://doi.org/10.3938/jkps.57.1122 bibtex: '@article{Bornmann_Hemsel_Littmann_Ageba_Kadota_Morita_2010, title={Ultrasonic Transducer for the Hydrothermal Method}, volume={57}, DOI={10.3938/jkps.57.1122}, number={4}, journal={Journal of Korean Physical Society}, author={Bornmann, Peter and Hemsel, Tobias and Littmann, Walter and Ageba, Ryo and Kadota, Yoishi and Morita, Takeshi}, year={2010}, pages={1122} }' chicago: 'Bornmann, Peter, Tobias Hemsel, Walter Littmann, Ryo Ageba, Yoishi Kadota, and Takeshi Morita. “Ultrasonic Transducer for the Hydrothermal Method.” Journal of Korean Physical Society 57, no. 4 (2010): 1122. https://doi.org/10.3938/jkps.57.1122.' ieee: P. Bornmann, T. Hemsel, W. Littmann, R. Ageba, Y. Kadota, and T. Morita, “Ultrasonic Transducer for the Hydrothermal Method,” Journal of Korean Physical Society, vol. 57, no. 4, p. 1122, 2010. mla: Bornmann, Peter, et al. “Ultrasonic Transducer for the Hydrothermal Method.” Journal of Korean Physical Society, vol. 57, no. 4, 2010, p. 1122, doi:10.3938/jkps.57.1122. short: P. Bornmann, T. Hemsel, W. Littmann, R. Ageba, Y. Kadota, T. Morita, Journal of Korean Physical Society 57 (2010) 1122. date_created: 2019-05-13T09:37:56Z date_updated: 2022-01-06T07:04:19Z department: - _id: '151' doi: 10.3938/jkps.57.1122 intvolume: ' 57' issue: '4' keyword: - High-temperature transducer - Hydrothermal method - Lithium-niobate transducer language: - iso: eng page: '1122' publication: Journal of Korean Physical Society publication_identifier: issn: - 1948-5719 quality_controlled: '1' status: public title: Ultrasonic Transducer for the Hydrothermal Method type: journal_article user_id: '55222' volume: 57 year: '2010' ... --- _id: '9758' abstract: - lang: eng text: As a lead-free piezoelectric ceramics, (K,Na)NbO$_{3}$ is a promising material because of its good piezoelectric properties. In this study, (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics were synthesized from a KNbO$_{3}$ and NaNbO$_{3}$ mixture powder prepared by the hydrothermal reaction. The hydrothermal reaction enables the production of high quality powder for the ceramics fabrication process. To obtain (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics, these two powders KNbO$_{3}$ and NaNbO$_{3}$ were mixed and then sintered together. X-Ray diffraction analysis revealed that the solid solution ceramics (K$_{1-x}$Na$_{x}$)NbO$_{3}$ was produced by the sintering process. The K/Na ratio in (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics was optimized for the best piezoelectric properties. The optimized forms was (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$, which showed the following piezoelectric properties; k$_{33}$=0.56, d$_{33}$=114pC/N. In addition, the ferroelectric properties, P$_{r}$=7.72mC/cm$^{2}$, E$_{c}$=857V/mm, and the Curie temperature T$_{c}$=420$_{o}$C were also measured. author: - first_name: Takafumi full_name: Maeda, Takafumi last_name: Maeda - first_name: Norihito full_name: Takiguchi, Norihito last_name: Takiguchi - first_name: Takeshi full_name: Morita, Takeshi last_name: Morita - first_name: Mutsuo full_name: Ishikawa, Mutsuo last_name: Ishikawa - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel citation: ama: Maeda T, Takiguchi N, Morita T, Ishikawa M, Hemsel T. Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics. Journal of Korean Physical Society. 2010;57(4):924-928. doi:10.3938/jkps.57.924 apa: Maeda, T., Takiguchi, N., Morita, T., Ishikawa, M., & Hemsel, T. (2010). Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics. Journal of Korean Physical Society, 57(4), 924–928. https://doi.org/10.3938/jkps.57.924 bibtex: '@article{Maeda_Takiguchi_Morita_Ishikawa_Hemsel_2010, title={Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics}, volume={57}, DOI={10.3938/jkps.57.924}, number={4}, journal={Journal of Korean Physical Society}, author={Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}, year={2010}, pages={924–928} }' chicago: 'Maeda, Takafumi, Norihito Takiguchi, Takeshi Morita, Mutsuo Ishikawa, and Tobias Hemsel. “Hydrothermal (K1-XNax)NbO3 Lead-Free Piezoelectric Ceramics.” Journal of Korean Physical Society 57, no. 4 (2010): 924–28. https://doi.org/10.3938/jkps.57.924.' ieee: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, and T. Hemsel, “Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics,” Journal of Korean Physical Society, vol. 57, no. 4, pp. 924–928, 2010. mla: Maeda, Takafumi, et al. “Hydrothermal (K1-XNax)NbO3 Lead-Free Piezoelectric Ceramics.” Journal of Korean Physical Society, vol. 57, no. 4, 2010, pp. 924–28, doi:10.3938/jkps.57.924. short: T. Maeda, N. Takiguchi, T. Morita, M. Ishikawa, T. Hemsel, Journal of Korean Physical Society 57 (2010) 924–928. date_created: 2019-05-13T10:19:43Z date_updated: 2022-01-06T07:04:19Z department: - _id: '151' doi: 10.3938/jkps.57.924 intvolume: ' 57' issue: '4' keyword: - Lead-free piezoelectric material - KNN - Hydrothermal method language: - iso: eng page: 924-928 publication: Journal of Korean Physical Society publication_identifier: issn: - 1948-5719 quality_controlled: '1' status: public title: Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics type: journal_article user_id: '55222' volume: 57 year: '2010' ...