Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195903
M. Blomqvist, J. Koh, S. Khartsev, A. Grishin
Sodium potassium niobate (Na,K)NbO/sub 3/ (NKN) thin films were grown by rf-magnetron sputtering from stoichiometric Na/sub 0.5/K/sub 0.5/NbO/sub 3/ target on LaAlO/sub 3/ (LAO) single crystals and polycrystalline Pt/sub 80/Ir/sub 20/ (PtIr) substrates. NKN films on polycrystalline PtIr substrates were found to be preferentially (00l) oriented while XRD measurements reveal epitaxial quality of NKN/LaAlO/sub 3/ film structures. The ferroelectric state in NKN/PtIr films at room temperature is indicated by polarization loops with polarization as high as 33.4 /spl mu/C/cm/sup 2/ at 700 kV/cm remnant polarization of 9.9 /spl mu/C/cm/sup 2/, and coercive field of 91 kV/cm. I-V characteristics of vertical Au/NKN/PtIr capacitive cells and planar Au/NKN/LAO interdigital capacitors (IDCs) showed very good insulating properties. For NKN IDC the leakage current density was in the order of 30 nA/cm/sup 2/ at 400 kV/cm. Rf dielectric spectroscopy demonstrates low loss, low frequency dispersion, and high voltage tunability both for vertical Au/NKN/PtIr and planar interdigital Au/NKN/LAO capacitors.
{"title":"Rf-magnetron sputtered ferroelectric (Na,K)NbO/sub 3/ films","authors":"M. Blomqvist, J. Koh, S. Khartsev, A. Grishin","doi":"10.1109/ISAF.2002.1195903","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195903","url":null,"abstract":"Sodium potassium niobate (Na,K)NbO/sub 3/ (NKN) thin films were grown by rf-magnetron sputtering from stoichiometric Na/sub 0.5/K/sub 0.5/NbO/sub 3/ target on LaAlO/sub 3/ (LAO) single crystals and polycrystalline Pt/sub 80/Ir/sub 20/ (PtIr) substrates. NKN films on polycrystalline PtIr substrates were found to be preferentially (00l) oriented while XRD measurements reveal epitaxial quality of NKN/LaAlO/sub 3/ film structures. The ferroelectric state in NKN/PtIr films at room temperature is indicated by polarization loops with polarization as high as 33.4 /spl mu/C/cm/sup 2/ at 700 kV/cm remnant polarization of 9.9 /spl mu/C/cm/sup 2/, and coercive field of 91 kV/cm. I-V characteristics of vertical Au/NKN/PtIr capacitive cells and planar Au/NKN/LAO interdigital capacitors (IDCs) showed very good insulating properties. For NKN IDC the leakage current density was in the order of 30 nA/cm/sup 2/ at 400 kV/cm. Rf dielectric spectroscopy demonstrates low loss, low frequency dispersion, and high voltage tunability both for vertical Au/NKN/PtIr and planar interdigital Au/NKN/LAO capacitors.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133655230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195868
C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze
Implementation of a discrete Fourier transform in conjunction with Devonshire phenomenology allows the electromechanical response of an electroactive material to be fully characterized. The main thrust of this examination is the incorporation of signal decomposition through Fourier analysis to quantify the electro-mechanical and aging properties. Fourier analysis is a well-used technique in the electrical engineering community; however, it has not been applied to materials. The application presented here allows a fresh look at some old phenomena. The spectral representation provides to the underlying physics of the response, i.e., odd harmonics only exist for acentric materials. The ability to create the harmonic spectrum also provides a new way to characterize the effects of aging by revealing subtle changes in the fundamental components that comprise the response. This study shows how Fourier analysis can be applied to a PMN-PT-BT composition to characterize and quantify its electromechanical properties.
{"title":"Spectral analysis of the electromechanical response of an electroactive material by implementation of Fourier decomposition","authors":"C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze","doi":"10.1109/ISAF.2002.1195868","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195868","url":null,"abstract":"Implementation of a discrete Fourier transform in conjunction with Devonshire phenomenology allows the electromechanical response of an electroactive material to be fully characterized. The main thrust of this examination is the incorporation of signal decomposition through Fourier analysis to quantify the electro-mechanical and aging properties. Fourier analysis is a well-used technique in the electrical engineering community; however, it has not been applied to materials. The application presented here allows a fresh look at some old phenomena. The spectral representation provides to the underlying physics of the response, i.e., odd harmonics only exist for acentric materials. The ability to create the harmonic spectrum also provides a new way to characterize the effects of aging by revealing subtle changes in the fundamental components that comprise the response. This study shows how Fourier analysis can be applied to a PMN-PT-BT composition to characterize and quantify its electromechanical properties.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133541493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195953
K. Kao, Chien-Chuan Cheng, Ying-Chung Chen, Chien-Hsing Chen
Surface acoustic wave (SAW) filter properties such as center frequency (F/sub c/) and 3dB bandwidth of aluminum nitride (AlN) thin films sputtered on z-cut LiNbO/sub 3/ substrates were investigated. Highly c-axis prefer-oriented AlN thin films deposited on z-cut LiNbO/sub 3/ substrates were obtained by reactive rf magnetron sputtering. The results of our experiments showed that F/sub c/ of SAW filter was increased significantly for the increase of h//spl lambda/, where h was the AlN film thickness and /spl lambda/ was the wavelength of SAW. Comparing the SAW propagate along with the z-cut LiNbO/sub 3/ single crystal, the AlN/LiNbO/sub 3/ based surface acoustic wave (SAW) devices could improve the velocity of SAW. The 3dB bandwidth of SAW filter was decreased by the increase of h//spl lambda/ meaning that frequency selection getting stricter.
{"title":"Surface acoustic wave bandpass filters properties of AlN thin films sputtered on LiNbO/sub 3/ substrates","authors":"K. Kao, Chien-Chuan Cheng, Ying-Chung Chen, Chien-Hsing Chen","doi":"10.1109/ISAF.2002.1195953","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195953","url":null,"abstract":"Surface acoustic wave (SAW) filter properties such as center frequency (F/sub c/) and 3dB bandwidth of aluminum nitride (AlN) thin films sputtered on z-cut LiNbO/sub 3/ substrates were investigated. Highly c-axis prefer-oriented AlN thin films deposited on z-cut LiNbO/sub 3/ substrates were obtained by reactive rf magnetron sputtering. The results of our experiments showed that F/sub c/ of SAW filter was increased significantly for the increase of h//spl lambda/, where h was the AlN film thickness and /spl lambda/ was the wavelength of SAW. Comparing the SAW propagate along with the z-cut LiNbO/sub 3/ single crystal, the AlN/LiNbO/sub 3/ based surface acoustic wave (SAW) devices could improve the velocity of SAW. The 3dB bandwidth of SAW filter was decreased by the increase of h//spl lambda/ meaning that frequency selection getting stricter.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134172148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195876
K. Wakino
Several equations of mixing rule on permittivity have been proposed, but none of these equations is not perfect, because of too many different configurations exist in actual cases. Serial model and parallel model are two extremes of mixing manner. For the random mixture of fine particles, which does not have a remarkable aspect ratio, customarily the logarithmic mixing rule has been applied. But, the logarithmic mixing rule does not estimate the correct apparent permittivity in low or high mixing rate. The author proposed new equation for the mixing rule that gives better agreement with measured value for whole range of mixing rate compared to the logarithmic rule. In this paper, a desirable refinement on the equation in previous paper is made to adapt to the structural image of actual compound and then the equation has been expanded to the complex permittivity to apply the equation on the dissipative materials cases.
{"title":"Improved mixing rule on permittivity","authors":"K. Wakino","doi":"10.1109/ISAF.2002.1195876","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195876","url":null,"abstract":"Several equations of mixing rule on permittivity have been proposed, but none of these equations is not perfect, because of too many different configurations exist in actual cases. Serial model and parallel model are two extremes of mixing manner. For the random mixture of fine particles, which does not have a remarkable aspect ratio, customarily the logarithmic mixing rule has been applied. But, the logarithmic mixing rule does not estimate the correct apparent permittivity in low or high mixing rate. The author proposed new equation for the mixing rule that gives better agreement with measured value for whole range of mixing rate compared to the logarithmic rule. In this paper, a desirable refinement on the equation in previous paper is made to adapt to the structural image of actual compound and then the equation has been expanded to the complex permittivity to apply the equation on the dissipative materials cases.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133304430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195864
D. Xue, S. Wu, R. Jayavel, K. Terabe, S. Kurimura, K. Kitamura
The domain structure of lithium niobate single crystals is studied from the corresponding crystallographic characteristics at different temperatures (ranging from room temperature to the Curie temperature). The temperature dependent nature of the domain reversal and domain structures of such ferroelectric crystals have been quantitatively analyzed. Various constituent chemical bonds and oxygen octahedra (formed by these bonds) of ferroelectric lithium niobate crystals are utilized as the starting point of this work. At low temperatures, the domain structure is simplex and regular owing to the regular occupancy of constituent ions at the corresponding lattice sites (of the space group R3c). With temperature increasing, the domain structure of the ferroelectric lithium niobate crystal becomes complex, due to the complicated site occupancies of constituent ions. At high temperatures, the multi-domain is formed owing to the fact that vacant sites are energetically available for Li/sup +/ cations (i.e., the random location of Li/sup +/ cations in the crystallographic frame).
{"title":"Temperature dependant domain structures of lithium niobate single crystals","authors":"D. Xue, S. Wu, R. Jayavel, K. Terabe, S. Kurimura, K. Kitamura","doi":"10.1109/ISAF.2002.1195864","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195864","url":null,"abstract":"The domain structure of lithium niobate single crystals is studied from the corresponding crystallographic characteristics at different temperatures (ranging from room temperature to the Curie temperature). The temperature dependent nature of the domain reversal and domain structures of such ferroelectric crystals have been quantitatively analyzed. Various constituent chemical bonds and oxygen octahedra (formed by these bonds) of ferroelectric lithium niobate crystals are utilized as the starting point of this work. At low temperatures, the domain structure is simplex and regular owing to the regular occupancy of constituent ions at the corresponding lattice sites (of the space group R3c). With temperature increasing, the domain structure of the ferroelectric lithium niobate crystal becomes complex, due to the complicated site occupancies of constituent ions. At high temperatures, the multi-domain is formed owing to the fact that vacant sites are energetically available for Li/sup +/ cations (i.e., the random location of Li/sup +/ cations in the crystallographic frame).","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133527858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195907
Wenbiao Wu, Dong-wen Peng, Xiaofeng Liang, Z. Meng
Ba/sub 0.6/Sr/sub 0.4/TiO/sub 3/ thin films were prepared on LaAlO/sub 3/ substrates by sol-gel method. The effects of annealing temperature on the structure and dielectric properties were studied. The microstructure was examined by XRD, SEM and AFM. It was observed that as the annealing temperature increased, films were crystallized in preferential (001) orientation. When annealed at 1100/spl deg/C, the films reveal agglomeration structure, and surface roughness increase. By the measurement, we found that the dielectric properties strongly depend upon annealing temperature. The higher the annealing temperature, the lower dissipation factor and the larger tunability will be. At the same thickness, the tunability of the films annealed at 1100/spl deg/C enhanced to 46.9% (DC bias electric field of 80KV/cm) and the dissipation factor is 0.008 at 1 MHz.
{"title":"The effect of annealing temperature on the structure and dielectric properties of (Ba/sub 0.6/Sr/sub 0.4/)TiO/sub 3/ thin films","authors":"Wenbiao Wu, Dong-wen Peng, Xiaofeng Liang, Z. Meng","doi":"10.1109/ISAF.2002.1195907","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195907","url":null,"abstract":"Ba/sub 0.6/Sr/sub 0.4/TiO/sub 3/ thin films were prepared on LaAlO/sub 3/ substrates by sol-gel method. The effects of annealing temperature on the structure and dielectric properties were studied. The microstructure was examined by XRD, SEM and AFM. It was observed that as the annealing temperature increased, films were crystallized in preferential (001) orientation. When annealed at 1100/spl deg/C, the films reveal agglomeration structure, and surface roughness increase. By the measurement, we found that the dielectric properties strongly depend upon annealing temperature. The higher the annealing temperature, the lower dissipation factor and the larger tunability will be. At the same thickness, the tunability of the films annealed at 1100/spl deg/C enhanced to 46.9% (DC bias electric field of 80KV/cm) and the dissipation factor is 0.008 at 1 MHz.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114787369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195887
A. Zomorrodian, N. Wu, S. Wilczak, C. Colbert, A. Ignatiev, C. Garcia
A new ceramic optical microdetector has been developed for retinal implant as a direct replacement for damaged retinal photo-detectors in patients with dystrophies such as Retinitis Pigmentosa (RP) and Age-related Macular degeneration (AMD). The thin film optical detector (TOD) is a heterostructure device composed of an atomically ordered La-doped PbZrTiO/sub 3/(PLZT) layer epitaxially grown on an atomically ordered Pt thin film layer. The TOD has an optical response, which in the visible region has a peak at around 550 nm with a sensitivity that overlaps the eye response from 400 nm to 650 nm. The device responsivity in the visible range is at a value of /spl sim/ 1000 V/W. Individual detectors are fabricated by photolithography and etch processing as is common in the microelectronics industry. Detectors 40 /spl mu/m in diameter have been processed and have been integrated with a newly developed polymer carrier layer technique for ease of handling and implantation of microdetector arrays into the eye.
{"title":"La-doped PbZrTiO/sub 3/(PLZT) thin film optical detectors (TOD) for retinal implantation-a \"bionic\" eye","authors":"A. Zomorrodian, N. Wu, S. Wilczak, C. Colbert, A. Ignatiev, C. Garcia","doi":"10.1109/ISAF.2002.1195887","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195887","url":null,"abstract":"A new ceramic optical microdetector has been developed for retinal implant as a direct replacement for damaged retinal photo-detectors in patients with dystrophies such as Retinitis Pigmentosa (RP) and Age-related Macular degeneration (AMD). The thin film optical detector (TOD) is a heterostructure device composed of an atomically ordered La-doped PbZrTiO/sub 3/(PLZT) layer epitaxially grown on an atomically ordered Pt thin film layer. The TOD has an optical response, which in the visible region has a peak at around 550 nm with a sensitivity that overlaps the eye response from 400 nm to 650 nm. The device responsivity in the visible range is at a value of /spl sim/ 1000 V/W. Individual detectors are fabricated by photolithography and etch processing as is common in the microelectronics industry. Detectors 40 /spl mu/m in diameter have been processed and have been integrated with a newly developed polymer carrier layer technique for ease of handling and implantation of microdetector arrays into the eye.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123287424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195956
K. Harada, Y. Hosono, Y. Yamashita
Piezoelectric single crystals of Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) 40 mm in diameter were grown with PbO flux by the solution Bridgman method. The prerequisites for the growth of PZNT 93/7 single crystals are higher melting temperature, a longer melting time than Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ (PZNT 91/9), and the addition of ZnO. The pyrochlore pellets of PZNT 93/7 are more stable than those of PZNT 91/9. The Curie temperature is 155-175/spl deg/C and the temperature corresponds to the rhombohedral-tetragonal phase change, T/sub rt/, is higher than 100/spl deg/C for PZNT 93/7 single crystals. T/sub rt/ corresponds to the degradation boundary temperature of the electromechanical coupling coefficient, k/sub 33/, and also of the dielectric constant. The sensitivity degradation of ultrasonic transducers using PZNT 93/7 single crystals can be avoided up to a high temperature of about 100/spl deg/C. Although the piezoelectric properties of single crystals of PZNT 91/9 are excellent, it has become clear that the electromechanical coupling coefficient, k/sub 33/, and other properties degrade drastically above about 80/spl deg/C. Therefore, our results indicate that PZNT 93/7 has good potential for application in the mass production of ultrasonic transducers.
{"title":"Single-crystal Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) for highly reliable ultrasonic transducers","authors":"K. Harada, Y. Hosono, Y. Yamashita","doi":"10.1109/ISAF.2002.1195956","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195956","url":null,"abstract":"Piezoelectric single crystals of Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.93/Ti/sub 0.07/]O/sub 3/ (PZNT 93/7) 40 mm in diameter were grown with PbO flux by the solution Bridgman method. The prerequisites for the growth of PZNT 93/7 single crystals are higher melting temperature, a longer melting time than Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ (PZNT 91/9), and the addition of ZnO. The pyrochlore pellets of PZNT 93/7 are more stable than those of PZNT 91/9. The Curie temperature is 155-175/spl deg/C and the temperature corresponds to the rhombohedral-tetragonal phase change, T/sub rt/, is higher than 100/spl deg/C for PZNT 93/7 single crystals. T/sub rt/ corresponds to the degradation boundary temperature of the electromechanical coupling coefficient, k/sub 33/, and also of the dielectric constant. The sensitivity degradation of ultrasonic transducers using PZNT 93/7 single crystals can be avoided up to a high temperature of about 100/spl deg/C. Although the piezoelectric properties of single crystals of PZNT 91/9 are excellent, it has become clear that the electromechanical coupling coefficient, k/sub 33/, and other properties degrade drastically above about 80/spl deg/C. Therefore, our results indicate that PZNT 93/7 has good potential for application in the mass production of ultrasonic transducers.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123634773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195927
C. Chong, H. Chan, M. Chan, P. Liu
PZT/epoxy 1-3 composite rings with PZT volume fractions /spl Phi/ ranging from 0.58 to 0.93 are fabricated. They have sufficiently small epoxy width (/spl sim/77 81 /spl mu/m) and can be treated as effective homogeneous media. The mode coupling theory and a finite element model (FEM) are applied to predict the thickness (f/sub T/), lateral (f/sub L/), radial (f/sub R/) and wall-thickness (f/sub W/) resonances of the composite rings. As the frequencies and electromechanical coupling coefficients play a significant role in the performance of composite transducer, it is important to know how these parameters change with /spl Phi/. Good agreements are found between the experimental results and the FEM simulations. It is obvious that f/sub R/ and f/sub W/ vibrations greatly deteriorate at low value of /spl Phi/. To avoid unwanted modes from coupling to f/sub T/, the thickness and configuration of the PZT elements in the rings should be optimized.
{"title":"Analysis of the resonance modes of PZT/epoxy 1-3 composite rings","authors":"C. Chong, H. Chan, M. Chan, P. Liu","doi":"10.1109/ISAF.2002.1195927","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195927","url":null,"abstract":"PZT/epoxy 1-3 composite rings with PZT volume fractions /spl Phi/ ranging from 0.58 to 0.93 are fabricated. They have sufficiently small epoxy width (/spl sim/77 81 /spl mu/m) and can be treated as effective homogeneous media. The mode coupling theory and a finite element model (FEM) are applied to predict the thickness (f/sub T/), lateral (f/sub L/), radial (f/sub R/) and wall-thickness (f/sub W/) resonances of the composite rings. As the frequencies and electromechanical coupling coefficients play a significant role in the performance of composite transducer, it is important to know how these parameters change with /spl Phi/. Good agreements are found between the experimental results and the FEM simulations. It is obvious that f/sub R/ and f/sub W/ vibrations greatly deteriorate at low value of /spl Phi/. To avoid unwanted modes from coupling to f/sub T/, the thickness and configuration of the PZT elements in the rings should be optimized.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128788949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195898
C. Wang, M. Kao, Y. Chen
Ferroelectric polymer/ceramic structure thin films were fabricated on Pt/SiO/sub 2//Si substrates using a sol-gel method. The bilayer thin film was composed of polar /spl beta/-phase poly(vinylidene fluoride) (PVDF) and 1 /spl mu/m thickness of polycrystalline lead titanate (PbTiO/sub 3/) thin film. By changing the concentrations of PVDF solutions (0.6/spl sim/1.0 M), various thickness of PVDF thin films (50-580 nm) were obtained, and the effects of various processing parameters on the characteristics of PVDF/PbTiO/sub 3/ thin films were studied. The characteristic of the /spl beta/ phase at infrared spectrum of 511 and 840 cm/sup -1/ can be observed in PVDF film crystallized at 65/spl deg/C for 2 h. With the increase of the PVDF thickness of the PVDF/PbTiO/sub 3/ films, the relative dielectric constant (/spl epsi//sub r/) decreased from 63 to 20 and the leakage current density (J) also decreased from 1.54 /spl times/ 10/sup -6/ to 3.86 /spl times/ 10/sup -7/ A/cm/sup 2/.
{"title":"Preparation and electrical property of /spl beta/-PVDF/PbTiO/sub 3/ thin films","authors":"C. Wang, M. Kao, Y. Chen","doi":"10.1109/ISAF.2002.1195898","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195898","url":null,"abstract":"Ferroelectric polymer/ceramic structure thin films were fabricated on Pt/SiO/sub 2//Si substrates using a sol-gel method. The bilayer thin film was composed of polar /spl beta/-phase poly(vinylidene fluoride) (PVDF) and 1 /spl mu/m thickness of polycrystalline lead titanate (PbTiO/sub 3/) thin film. By changing the concentrations of PVDF solutions (0.6/spl sim/1.0 M), various thickness of PVDF thin films (50-580 nm) were obtained, and the effects of various processing parameters on the characteristics of PVDF/PbTiO/sub 3/ thin films were studied. The characteristic of the /spl beta/ phase at infrared spectrum of 511 and 840 cm/sup -1/ can be observed in PVDF film crystallized at 65/spl deg/C for 2 h. With the increase of the PVDF thickness of the PVDF/PbTiO/sub 3/ films, the relative dielectric constant (/spl epsi//sub r/) decreased from 63 to 20 and the leakage current density (J) also decreased from 1.54 /spl times/ 10/sup -6/ to 3.86 /spl times/ 10/sup -7/ A/cm/sup 2/.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126373403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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