Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195897
K. Ohnuki, T. Higuchi, M. Takayasu, M. Sogawa, T. Tsukamoto
Ferroelectric Ba/sub 2/NaNb/sub 5/O/sub 15/ (BNN) thin films were prepared on MgO (100) substrates by pulsed laser deposition method. When the laser power density and repetition frequency were fixed at 200 mJ/cm/sup 2/ and 5 Hz, respectively, the c-axis oriented BNN thin film was obtained at substrate temperature of 650/spl deg/C. The interface between the c-axis oriented BNN thin film and MgO substrate was very smooth. The band gap of the c-axis oriented BNN thin film was about 3.1 eV, which accords to that of the BNN single crystal.
{"title":"Low-temperature preparation of ferroelectric Ba/sub 2/NaNb/sub 5/O/sub 15/ thin films by pulsed laser deposition","authors":"K. Ohnuki, T. Higuchi, M. Takayasu, M. Sogawa, T. Tsukamoto","doi":"10.1109/ISAF.2002.1195897","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195897","url":null,"abstract":"Ferroelectric Ba/sub 2/NaNb/sub 5/O/sub 15/ (BNN) thin films were prepared on MgO (100) substrates by pulsed laser deposition method. When the laser power density and repetition frequency were fixed at 200 mJ/cm/sup 2/ and 5 Hz, respectively, the c-axis oriented BNN thin film was obtained at substrate temperature of 650/spl deg/C. The interface between the c-axis oriented BNN thin film and MgO substrate was very smooth. The band gap of the c-axis oriented BNN thin film was about 3.1 eV, which accords to that of the BNN single crystal.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"20 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":"132709950","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.2002.1195931
R. Aoyagi, M. Matsushita, K. Komagata, H. Takeda, S. Okamura, T. Shiosaki
The piezoelectric properties of bismuth layer-structured ferroelectrics Na/sub 0.5-x/Bi/sub 0.5+x/3/Bi/sub 2/Ta/sub 2/O/sub 9/ (NBT(x)) dense ceramics were investigated, and the crystal structure of synthesized NBT(x) powders was analyzed by the Rietveld method. NBT(x) powder and ceramics were prepared by conventional synthesis method. NBT(x) powder for x = 0 and x = 0.1 was confirmed to be single phase of BLSFs (m = 2) by x-ray diffraction method. The electromechanical coupling coefficients k/sub p/ of NBT(x = 0) and NBT(x = 0.1) dense ceramics were 10% and 8.3%, respectively. The k/sub p/ of NBT(x = 0) was one of the largest in reported non-oriented BLSFs ceramics.
{"title":"Piezoelectric properties and structural characterization of (Na,Bi)Bi/sub 2/Ta/sub 2/O/sub 9/ ceramics with bismuth layer-structure","authors":"R. Aoyagi, M. Matsushita, K. Komagata, H. Takeda, S. Okamura, T. Shiosaki","doi":"10.1109/ISAF.2002.1195931","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195931","url":null,"abstract":"The piezoelectric properties of bismuth layer-structured ferroelectrics Na/sub 0.5-x/Bi/sub 0.5+x/3/Bi/sub 2/Ta/sub 2/O/sub 9/ (NBT(x)) dense ceramics were investigated, and the crystal structure of synthesized NBT(x) powders was analyzed by the Rietveld method. NBT(x) powder and ceramics were prepared by conventional synthesis method. NBT(x) powder for x = 0 and x = 0.1 was confirmed to be single phase of BLSFs (m = 2) by x-ray diffraction method. The electromechanical coupling coefficients k/sub p/ of NBT(x = 0) and NBT(x = 0.1) dense ceramics were 10% and 8.3%, respectively. The k/sub p/ of NBT(x = 0) was one of the largest in reported non-oriented BLSFs ceramics.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"23 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":"132050292","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.2002.1195954
Chien-Chuan Cheng, K. Kao, Ying-Chung Chen
The temperature characteristics for surface acoustic wave (SAW) in annealed proton-exchanged (APE) LiNbO/sub 3/ waveguides were investigated. The process performed by immersing z-cut LiNbO/sub 3/ substrates in pure octanoic acid was experimentally studied. The penetration depth of hydrogen assumed to be equal to the waveguide depth (d) was measured by secondary-ion mass spectrometry (SIMS). The annealing process was carried out in a horizontal furnace kept at 400/spl deg/C for 4 h under a dry O/sub 2/ gas flow. The velocity (V/sub p/) and temperature coefficient of frequency (TCF) of SAW measured by a network analyzer were observed. The results showed that the V/sub p/ and TCF in APE LiNbO/sub 3/ samples tended to improve in comparison with the PE LiNbO/sub 3/ samples. It exhibited that the annealing effect could result in a restoration of the decreased V/sub p/ and an improvement of TCF. However, the values of TCF in APE LiNbO/sub 3/ samples were larger than that of the unexchanged one.
{"title":"Temperature characteristics for surface acoustic wave in annealed proton-exchanged LiNbO/sub 3/ waveguides","authors":"Chien-Chuan Cheng, K. Kao, Ying-Chung Chen","doi":"10.1109/ISAF.2002.1195954","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195954","url":null,"abstract":"The temperature characteristics for surface acoustic wave (SAW) in annealed proton-exchanged (APE) LiNbO/sub 3/ waveguides were investigated. The process performed by immersing z-cut LiNbO/sub 3/ substrates in pure octanoic acid was experimentally studied. The penetration depth of hydrogen assumed to be equal to the waveguide depth (d) was measured by secondary-ion mass spectrometry (SIMS). The annealing process was carried out in a horizontal furnace kept at 400/spl deg/C for 4 h under a dry O/sub 2/ gas flow. The velocity (V/sub p/) and temperature coefficient of frequency (TCF) of SAW measured by a network analyzer were observed. The results showed that the V/sub p/ and TCF in APE LiNbO/sub 3/ samples tended to improve in comparison with the PE LiNbO/sub 3/ samples. It exhibited that the annealing effect could result in a restoration of the decreased V/sub p/ and an improvement of TCF. However, the values of TCF in APE LiNbO/sub 3/ samples were larger than that of the unexchanged one.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"78 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":"132182176","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.2002.1195969
Y. Ohya, T. Tamakoshi, T. Ban, Y. Takahashi
Lead zirconate titanate (PZT) films were fabricated by a sol-gel method. The sol was prepared using Ti(O/sup i/Pr)/sub 4/, Pb(OAc)/sub 2//spl middot/3H/sub 2/O, Zr(O/sup n/Bu)/sub 4/, and diethanolamine (DEA) with a molar ratio of DEA/(Ti+Zr)=1. They were dissolved in isopropanol solvent. The concentrations of the sol were about 1.5 and 0.4 mol/L with compositions of Pb/sub x/(Ti/sub 0.5/Zr/sub 0.5/)O/sub 3/, (x = 1.1 and 1.3). The substrate used was Si wafer sputtered with Pt as an electrode. The deposition was conducted by a dip-coating procedure. After deposition and drying at 110/spl deg/C, the substrate was heated at 700/spl deg/C for 30min to crystallize perovskite phase. This coating-drying-heating cycle was repeated several times to obtain a thick PZT film. The fabricated films was about 7 /spl mu/m thick by eight depositions and consisted of the first three thin layers (90 nm each) and five to eight thick layers (1.2 /spl mu/m each). The dielectric constant of the films was about 400 and tan/spl delta/ was about 0.01 at 1 kHz. The films exhibited typical ferroelectric P-E hysteresis curve and the remanent polarization and coercive force were 29.7 /spl mu/C/cm/sup 2/ and 69.7 kV/cm, respectively. The admittance measurement of the poled thick film exhibited clear resonance and antiresonance peaks. The piezoelectric displacement was measured by a laser interferometer and the piezoelectric constant, d/sub 33/, was calculated as 430 to 550 pm/V.
{"title":"Lead zirconate titanate thick films by sol-gel method for piezoelectric applications","authors":"Y. Ohya, T. Tamakoshi, T. Ban, Y. Takahashi","doi":"10.1109/ISAF.2002.1195969","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195969","url":null,"abstract":"Lead zirconate titanate (PZT) films were fabricated by a sol-gel method. The sol was prepared using Ti(O/sup i/Pr)/sub 4/, Pb(OAc)/sub 2//spl middot/3H/sub 2/O, Zr(O/sup n/Bu)/sub 4/, and diethanolamine (DEA) with a molar ratio of DEA/(Ti+Zr)=1. They were dissolved in isopropanol solvent. The concentrations of the sol were about 1.5 and 0.4 mol/L with compositions of Pb/sub x/(Ti/sub 0.5/Zr/sub 0.5/)O/sub 3/, (x = 1.1 and 1.3). The substrate used was Si wafer sputtered with Pt as an electrode. The deposition was conducted by a dip-coating procedure. After deposition and drying at 110/spl deg/C, the substrate was heated at 700/spl deg/C for 30min to crystallize perovskite phase. This coating-drying-heating cycle was repeated several times to obtain a thick PZT film. The fabricated films was about 7 /spl mu/m thick by eight depositions and consisted of the first three thin layers (90 nm each) and five to eight thick layers (1.2 /spl mu/m each). The dielectric constant of the films was about 400 and tan/spl delta/ was about 0.01 at 1 kHz. The films exhibited typical ferroelectric P-E hysteresis curve and the remanent polarization and coercive force were 29.7 /spl mu/C/cm/sup 2/ and 69.7 kV/cm, respectively. The admittance measurement of the poled thick film exhibited clear resonance and antiresonance peaks. The piezoelectric displacement was measured by a laser interferometer and the piezoelectric constant, d/sub 33/, was calculated as 430 to 550 pm/V.","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":"133410141","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.2002.1195962
A. Renault, H. Dammak, P. Gaucher, M. Pham Thi, G. Calvarin
The domain configuration and the electromechanical related properties have been studied in Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ (PZN-9%PT) single crystals cut along [001] and [101~]. It was established that soft (with high d) and hard (with lower d) piezoelectric properties are respectively obtained in a multidomain and a single domain configuration. The softer piezoelectric material (d/sub 33/ = 2700 pC/N, s/sub 33//sup E/ = 180 pN/m/sup 2/, k/sub 33/ = 93%) was found in the monoclinic multidomain state after poling with a small field along [001]. Optimal poling process and electromechanical related properties of the single crystals were discussed in term of the field-temperature diagram.
{"title":"Domain engineering of Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ single crystals and piezoelectric related properties","authors":"A. Renault, H. Dammak, P. Gaucher, M. Pham Thi, G. Calvarin","doi":"10.1109/ISAF.2002.1195962","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195962","url":null,"abstract":"The domain configuration and the electromechanical related properties have been studied in Pb[(Zn/sub 1/3/Nb/sub 2/3/)/sub 0.91/Ti/sub 0.09/]O/sub 3/ (PZN-9%PT) single crystals cut along [001] and [101~]. It was established that soft (with high d) and hard (with lower d) piezoelectric properties are respectively obtained in a multidomain and a single domain configuration. The softer piezoelectric material (d/sub 33/ = 2700 pC/N, s/sub 33//sup E/ = 180 pN/m/sup 2/, k/sub 33/ = 93%) was found in the monoclinic multidomain state after poling with a small field along [001]. Optimal poling process and electromechanical related properties of the single crystals were discussed in term of the field-temperature diagram.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"33 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":"131492120","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.2002.1195942
R. Gabl, M. Schreiter, R. Primig, D. Pitzer, W. Wersing
Applying ferroelectric materials for bulk acoustic resonators, the field dependency of piezoelectric properties has to be considered. In this work, to our knowledge for the first time, the electro-acoustic hysteresis properties of integrated PZT thin-film bulk acoustic resonators are comprehensively investigated. PZT thin film resonators with resonance frequencies around 1.8 GHz and Zr content ranging from 25% to 60% have been fabricated employing multi-target sputtering. The couple coefficient and the impedance characteristics are found to show a hysteresis behaviour particularly dependent on the Zr content. For PZT resonators with low Zr content we observe a distinctive dependence of anti-resonance on the applied field while the series resonance is mostly unaffected. This behaviour changes completely for samples with high Zr content where primarily the series resonance is found to vary dependent on the applied field, a dependence which is supposed to be the consequence of 109/spl deg//71/spl deg/ domain switching in the rhombohedral phase. As potential application making use of this field dependence of acoustic properties a band-width tuneable PZT FBAR based filter will be proposed.
{"title":"Hysteresis properties of Pb(Zr/sub x/Ti/sub 1-x/)O/sub 3/ thin-film bulk acoustic resonators","authors":"R. Gabl, M. Schreiter, R. Primig, D. Pitzer, W. Wersing","doi":"10.1109/ISAF.2002.1195942","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195942","url":null,"abstract":"Applying ferroelectric materials for bulk acoustic resonators, the field dependency of piezoelectric properties has to be considered. In this work, to our knowledge for the first time, the electro-acoustic hysteresis properties of integrated PZT thin-film bulk acoustic resonators are comprehensively investigated. PZT thin film resonators with resonance frequencies around 1.8 GHz and Zr content ranging from 25% to 60% have been fabricated employing multi-target sputtering. The couple coefficient and the impedance characteristics are found to show a hysteresis behaviour particularly dependent on the Zr content. For PZT resonators with low Zr content we observe a distinctive dependence of anti-resonance on the applied field while the series resonance is mostly unaffected. This behaviour changes completely for samples with high Zr content where primarily the series resonance is found to vary dependent on the applied field, a dependence which is supposed to be the consequence of 109/spl deg//71/spl deg/ domain switching in the rhombohedral phase. As potential application making use of this field dependence of acoustic properties a band-width tuneable PZT FBAR based filter will be proposed.","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":"116269246","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.2002.1195948
Haiyan Chen, X. Guo, Wenbiao Wu, Z. Meng
Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-Pb(Mn/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbZrO/sub 3/-PbTiO/sub 3/ (PMMN-PZT) quaternary piezoelectric ceramics with the various contents of Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/ (PMN), which locate in the vicinity of the morphotropic phase boundary (MPB), were fabricated. The phase structure of the system was delineated by X-ray diffraction analysis. The piezoelectric and dielectric properties were also measured. Experimental results reveal that the MPB coexisting tetragonal and rhombohedral phases in the present system has a broad composition region from 0.10 to 0.14mol% PM. The piezoelectric coefficient and electromechanical coupling factor increase with increasing PMN and reach the maximum values at 12mol% PMN, then decrease remarkably with further PMN addition, whereas the variation of Qm with PMN addition shows the opposite trend. The dielectric constant also reaches the maximum value at 12mol% PMN. It is found that compared with the as-sintered samples, the dielectric constant of the poled samples in tetragonal phase increases, while there are contrary results in rhombohedral phase. The variation of dielectric properties reflects the transition from tetragonal phase to rhombohedral phase.
{"title":"The influence of Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/ content on the piezoelectric and dielectric properties of PMNN-PZT system near the MPB","authors":"Haiyan Chen, X. Guo, Wenbiao Wu, Z. Meng","doi":"10.1109/ISAF.2002.1195948","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195948","url":null,"abstract":"Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-Pb(Mn/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbZrO/sub 3/-PbTiO/sub 3/ (PMMN-PZT) quaternary piezoelectric ceramics with the various contents of Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/ (PMN), which locate in the vicinity of the morphotropic phase boundary (MPB), were fabricated. The phase structure of the system was delineated by X-ray diffraction analysis. The piezoelectric and dielectric properties were also measured. Experimental results reveal that the MPB coexisting tetragonal and rhombohedral phases in the present system has a broad composition region from 0.10 to 0.14mol% PM. The piezoelectric coefficient and electromechanical coupling factor increase with increasing PMN and reach the maximum values at 12mol% PMN, then decrease remarkably with further PMN addition, whereas the variation of Qm with PMN addition shows the opposite trend. The dielectric constant also reaches the maximum value at 12mol% PMN. It is found that compared with the as-sintered samples, the dielectric constant of the poled samples in tetragonal phase increases, while there are contrary results in rhombohedral phase. The variation of dielectric properties reflects the transition from tetragonal phase to rhombohedral phase.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"13 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":"124472234","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.2002.1195939
J. Cannata, T. Shrout, K. Shung
Ultrasound backscatter microscope (UBM) imaging systems operating above 20 MHz are capable of achieving the axial and lateral resolutions needed for applications in ophthalmology and dermatology. Unfortunately these systems rely upon mechanically scanned single element transducers and suffer from a fixed focus, low frame rate and cumbersome scanning hardware. High frequency arrays are therefore desirable for several reasons, including the ability to dynamically focus the sound beam, increase frame rates and clinical convenience. This study investigates the design tradeoffs involved in the development of a high frequency (35 MHz) 64-element linear array. This array was designed primarily for human eye and skin imaging, and features monolithic elements mechanically diced out of a fine grain high density PZT-5H ceramic. Array elements were spaced with a 50 /spl mu/m pitch, interconnected via a flexible circuit and matched to the 50 /spl Omega/ system electronics via a 85 /spl Omega/ transmission line coaxial cable. Several prototype arrays were constructed with promising results. An average center frequency of 34 MHz with a -6 dB bandwidth of at least 45% per element was achieved. The maximum combined electrical and acoustical crosstalk for nearest and next nearest elements was less than -29 dB, and the average 40 dB pulse length was 105 ns.
{"title":"A 35 MHz linear ultrasonic array for medical imaging","authors":"J. Cannata, T. Shrout, K. Shung","doi":"10.1109/ISAF.2002.1195939","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195939","url":null,"abstract":"Ultrasound backscatter microscope (UBM) imaging systems operating above 20 MHz are capable of achieving the axial and lateral resolutions needed for applications in ophthalmology and dermatology. Unfortunately these systems rely upon mechanically scanned single element transducers and suffer from a fixed focus, low frame rate and cumbersome scanning hardware. High frequency arrays are therefore desirable for several reasons, including the ability to dynamically focus the sound beam, increase frame rates and clinical convenience. This study investigates the design tradeoffs involved in the development of a high frequency (35 MHz) 64-element linear array. This array was designed primarily for human eye and skin imaging, and features monolithic elements mechanically diced out of a fine grain high density PZT-5H ceramic. Array elements were spaced with a 50 /spl mu/m pitch, interconnected via a flexible circuit and matched to the 50 /spl Omega/ system electronics via a 85 /spl Omega/ transmission line coaxial cable. Several prototype arrays were constructed with promising results. An average center frequency of 34 MHz with a -6 dB bandwidth of at least 45% per element was achieved. The maximum combined electrical and acoustical crosstalk for nearest and next nearest elements was less than -29 dB, and the average 40 dB pulse length was 105 ns.","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":"129753343","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.2002.1195878
A. Grishin, V. Denysenkov
We report on nondestructive characterization of Thermal Barrier Coatings (TBC: YSZ/MCrAlY/Ni-superalloy). To test TBC we have employed the method of electromagnetic defectoscopy. We have modernized this method by applying microwave probe instead of RF coil: an open-ended coaxial probe was used to measure complex permittivity of dielectric material /spl epsiv/ = /spl epsiv/' + /spl epsiv/". The probe is basically a coaxial transmission line with an open end put into tight mechanical contact with the sample under test. Complex permittivity of the sample material was calculated from the coefficient of microwave reflection from the probe-sample interface. Using the probe the complex permittivity can be measured in a wide frequency range. Such broadband spectroscopy enables detection of foreign phase inclusions, delamination of dielectric layer and cracks on the ceramics/metal substrate interface, etc. Microwave probe enables noninvasive and nondestructive test of both small-area and large-area surfaces. Defects in the ceramic layer under test are revealed as anomalies of the dielectric permittivity on the background of almost constant /spl epsiv/, which is characteristic for the rest of the material.
{"title":"Broad band microwave probe for nondestructive test of dielectric coatings","authors":"A. Grishin, V. Denysenkov","doi":"10.1109/ISAF.2002.1195878","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195878","url":null,"abstract":"We report on nondestructive characterization of Thermal Barrier Coatings (TBC: YSZ/MCrAlY/Ni-superalloy). To test TBC we have employed the method of electromagnetic defectoscopy. We have modernized this method by applying microwave probe instead of RF coil: an open-ended coaxial probe was used to measure complex permittivity of dielectric material /spl epsiv/ = /spl epsiv/' + /spl epsiv/\". The probe is basically a coaxial transmission line with an open end put into tight mechanical contact with the sample under test. Complex permittivity of the sample material was calculated from the coefficient of microwave reflection from the probe-sample interface. Using the probe the complex permittivity can be measured in a wide frequency range. Such broadband spectroscopy enables detection of foreign phase inclusions, delamination of dielectric layer and cracks on the ceramics/metal substrate interface, etc. Microwave probe enables noninvasive and nondestructive test of both small-area and large-area surfaces. Defects in the ceramic layer under test are revealed as anomalies of the dielectric permittivity on the background of almost constant /spl epsiv/, which is characteristic for the rest of the material.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"30 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":"125960095","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.2002.1195929
H. Nagata, Y. Fujita, H. Enosawa, T. Takenaka
Piezoelectric properties of Bi/sub 4/Ti/sub 3-x/Nb/sub x/O/sub 12/ [BITN-x] and B/sub 4/Ti/sub 3-x/V/sub x/O/sub 12/ [BITV-x] ceramics are investigated. Furthermore, grain orientation effects of BITN and BITV ceramics on their piezoelectric properties are studied using the hot-forging (HF) method. The optimal sintering temperature of the BITV ceramic becomes lower with increasing the amount of doped-V ions. On the ordinarily fired (OF) sample with a random orientation, an electromechanical coupling factor, k/sub 33/ of BITN-0.08 and BITV-0.02 ceramics enhanced 0.20 and 0.25. On the HF sample, k/sub 33/ values of BITN-0.08 and BITV-0.04 ceramics enhanced the 0.39 and 0.38, respectively.
{"title":"Bi/sub 4/Ti/sub 3/O/sub 12/-based lead-free piezoelectric ceramics with grain orientation","authors":"H. Nagata, Y. Fujita, H. Enosawa, T. Takenaka","doi":"10.1109/ISAF.2002.1195929","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195929","url":null,"abstract":"Piezoelectric properties of Bi/sub 4/Ti/sub 3-x/Nb/sub x/O/sub 12/ [BITN-x] and B/sub 4/Ti/sub 3-x/V/sub x/O/sub 12/ [BITV-x] ceramics are investigated. Furthermore, grain orientation effects of BITN and BITV ceramics on their piezoelectric properties are studied using the hot-forging (HF) method. The optimal sintering temperature of the BITV ceramic becomes lower with increasing the amount of doped-V ions. On the ordinarily fired (OF) sample with a random orientation, an electromechanical coupling factor, k/sub 33/ of BITN-0.08 and BITV-0.02 ceramics enhanced 0.20 and 0.25. On the HF sample, k/sub 33/ values of BITN-0.08 and BITV-0.04 ceramics enhanced the 0.39 and 0.38, respectively.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"27 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":"126070834","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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