Pub Date : 2002-06-01DOI: 10.1109/ISAF.2002.1195881
M. Viviani, M. T. Buscaglia, V. Buscaglia, L. Mitoseriu, A. Testino, P. Nanni
The electrical properties of Er-doped BaTiO/sub 3/ ceramics with different amounts of dopant in the range (0.25-8) at.% and with electron compensation were studied using D.C.-resistance and impedance spectroscopy (IS) measurements. The experimental results were compared with the Double Barrier Schottky theory for the description of the PTCR effect. D.C. resistance results and microstructure analyses were used to discuss the role of dopant concentration, mechanism of incorporation and cooling rate on the PTCR behaviour. Optimum processing parameters that ensure the best PTCR ratio were found. IS measurements were performed at various temperature over the whole transition range and grain boundary and bulk contributions were extracted by a non linear least squares fitting procedure. Dielectric constant and resistivity values were obtained and used to derive model parameters for different samples. Temperature dependence of total resistivity was calculated and compared to D.C. curves. The agreement is good in a large range of temperature, including the ferro-para phase transition.
{"title":"Electrical properties of Er-doped BaTiO/sub 3/ ceramics for PTCR applications","authors":"M. Viviani, M. T. Buscaglia, V. Buscaglia, L. Mitoseriu, A. Testino, P. Nanni","doi":"10.1109/ISAF.2002.1195881","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195881","url":null,"abstract":"The electrical properties of Er-doped BaTiO/sub 3/ ceramics with different amounts of dopant in the range (0.25-8) at.% and with electron compensation were studied using D.C.-resistance and impedance spectroscopy (IS) measurements. The experimental results were compared with the Double Barrier Schottky theory for the description of the PTCR effect. D.C. resistance results and microstructure analyses were used to discuss the role of dopant concentration, mechanism of incorporation and cooling rate on the PTCR behaviour. Optimum processing parameters that ensure the best PTCR ratio were found. IS measurements were performed at various temperature over the whole transition range and grain boundary and bulk contributions were extracted by a non linear least squares fitting procedure. Dielectric constant and resistivity values were obtained and used to derive model parameters for different samples. Temperature dependence of total resistivity was calculated and compared to D.C. curves. The agreement is good in a large range of temperature, including the ferro-para phase transition.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127260923","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 : 2002-06-01DOI: 10.1109/ISAF.2002.1195885
M. Kao, C. Wang, Y. Chen
The novel pyroelectric infrared (IR) detectors have been fabricated using the Polyvinylidene Fluoride (PVDF)/Lead Titanate (PT) pyroelectric bilayer thin films which were deposited onto Pt(111)/SiO/sub 2//Si(100) substrates by a sol-gel process. The ceramic/polymer structure was constructed of the randomly oriented polycrystalline PT film(/spl sim/1 /spl mu/m) heated at 700/spl deg/C for 1 h and the /spl beta/-phase PVDF film crystallized at 65/spl deg/C for 2 h. The effects of PVDF thin film thickness (100/spl sim/580 nm) on the pyroelectric response of IR detectors were studied. The results show that the depositions of PVDF thin films onto the PT films will cause the leakage current (J) of the detectors decrease from 6.37 /spl times/ 10/sup -7/ A/cm/sup 2/ to 3.86 /spl times/ 10/sup -7/ A/cm/sup 2/. The specific detectivity (D*) measured at 100 Hz decreased from 2.72 /spl times/ 10/sup -7/ cm/spl middot/Hz/sup 1/2//W for detector without PVDF to 1.71 /spl times/ 10/sup -7/ cm/spl middot/Hz/sup 1/2//W for detector with PVDF thickness of 580 nm. By optimizing the ratio of the specific detectivity (D*) to leakage current, D*/J, the detector with PVDF thickness of 295 nm exhibits the best performance.
{"title":"Thickness-dependent leakage current of (PVDF/PbTiO/sub 3/) pyroelectric bilayer thin film detectors","authors":"M. Kao, C. Wang, Y. Chen","doi":"10.1109/ISAF.2002.1195885","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195885","url":null,"abstract":"The novel pyroelectric infrared (IR) detectors have been fabricated using the Polyvinylidene Fluoride (PVDF)/Lead Titanate (PT) pyroelectric bilayer thin films which were deposited onto Pt(111)/SiO/sub 2//Si(100) substrates by a sol-gel process. The ceramic/polymer structure was constructed of the randomly oriented polycrystalline PT film(/spl sim/1 /spl mu/m) heated at 700/spl deg/C for 1 h and the /spl beta/-phase PVDF film crystallized at 65/spl deg/C for 2 h. The effects of PVDF thin film thickness (100/spl sim/580 nm) on the pyroelectric response of IR detectors were studied. The results show that the depositions of PVDF thin films onto the PT films will cause the leakage current (J) of the detectors decrease from 6.37 /spl times/ 10/sup -7/ A/cm/sup 2/ to 3.86 /spl times/ 10/sup -7/ A/cm/sup 2/. The specific detectivity (D*) measured at 100 Hz decreased from 2.72 /spl times/ 10/sup -7/ cm/spl middot/Hz/sup 1/2//W for detector without PVDF to 1.71 /spl times/ 10/sup -7/ cm/spl middot/Hz/sup 1/2//W for detector with PVDF thickness of 580 nm. By optimizing the ratio of the specific detectivity (D*) to leakage current, D*/J, the detector with PVDF thickness of 295 nm exhibits the best performance.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123712918","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 : 2002-06-01DOI: 10.1109/ISAF.2002.1195947
T. Tsurumi, H. Kakemoto, S. Wada
The material coefficients of "soft"- and "hard"-PZTs were determined as complex values by the non-linear least-squares-fitting of immittance data measured for length-extensional bar resonators. The piezoelectric d-constant should be a complex value to obtain a best fitting between observed and calculated results. As the elastic, dielectric and piezoelectric losses determined in this process were not "intrinsic" losses, calculation process to evaluate the "intrinsic" losses was proposed. It was confirmed that the intrinsic losses were smaller than the corresponding extrinsic losses. The intrinsic piezoelectric loss existed in both soft- and hard-PZTs. About 50% of the loss of piezoelectric d-constant was derived from the elastic and dielectric losses. Most notable difference between the soft- and hard-PZTs were observed in their elastic losses.
{"title":"Dielectric, elastic and piezoelectric losses of PZT ceramics in the resonance state","authors":"T. Tsurumi, H. Kakemoto, S. Wada","doi":"10.1109/ISAF.2002.1195947","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195947","url":null,"abstract":"The material coefficients of \"soft\"- and \"hard\"-PZTs were determined as complex values by the non-linear least-squares-fitting of immittance data measured for length-extensional bar resonators. The piezoelectric d-constant should be a complex value to obtain a best fitting between observed and calculated results. As the elastic, dielectric and piezoelectric losses determined in this process were not \"intrinsic\" losses, calculation process to evaluate the \"intrinsic\" losses was proposed. It was confirmed that the intrinsic losses were smaller than the corresponding extrinsic losses. The intrinsic piezoelectric loss existed in both soft- and hard-PZTs. About 50% of the loss of piezoelectric d-constant was derived from the elastic and dielectric losses. Most notable difference between the soft- and hard-PZTs were observed in their elastic losses.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127913625","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.2002.1195894
T. Yamada, N. Wakiya, K. Shinozaki, N. Mizutani
The depth profiles of fixed charges in heteroepitaxial SrTiO/sub 3//CeO/sub 2//yttria-stabilized zirconia(YSZ)/Si and SrTiO/sub 3//MgO/Si structures were investigated using the capacitance-voltage (C-V) measurement of the films with slanted thickness. The heterostructures with slanted thickness were fabricated by pulsed laser deposition (PLD) using in-situ masking technique. It was found that there are negative fixed charges in both films. From the equivalent oxide thickness dependence of the mid-gap voltage, it was clarified that these negative charges are located at the interface between layers and near the ultra thin layer on Si.
{"title":"Depth profile of fixed charge in epitaxial oxide films on silicon substrate for MFIS structure","authors":"T. Yamada, N. Wakiya, K. Shinozaki, N. Mizutani","doi":"10.1109/ISAF.2002.1195894","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195894","url":null,"abstract":"The depth profiles of fixed charges in heteroepitaxial SrTiO/sub 3//CeO/sub 2//yttria-stabilized zirconia(YSZ)/Si and SrTiO/sub 3//MgO/Si structures were investigated using the capacitance-voltage (C-V) measurement of the films with slanted thickness. The heterostructures with slanted thickness were fabricated by pulsed laser deposition (PLD) using in-situ masking technique. It was found that there are negative fixed charges in both films. From the equivalent oxide thickness dependence of the mid-gap voltage, it was clarified that these negative charges are located at the interface between layers and near the ultra thin layer on Si.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"14 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":"123075883","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.2002.1195858
R. Bouregba, G. Poullain
A novel approach is proposed to compute the ferroelectric polarization by correcting numerically for both parasitic disturbing S-T hysteresis measurements and possible interfacial layers. This is achieved by taking into account all the charges flowing in a S-T circuit.
{"title":"Novel numerical method to correct for both circuit distortions and passive layers effect affecting Sawyer-Tower ferroelectric thin films hysteresis measurements","authors":"R. Bouregba, G. Poullain","doi":"10.1109/ISAF.2002.1195858","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195858","url":null,"abstract":"A novel approach is proposed to compute the ferroelectric polarization by correcting numerically for both parasitic disturbing S-T hysteresis measurements and possible interfacial layers. This is achieved by taking into account all the charges flowing in a S-T circuit.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"215 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":"122406118","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.2002.1195937
Z. Gui, Xiaobing Hu, Longtu Li
This paper describes a kind of bimorph flexural piezoelectric ultrasonic transducer (abbreviated as PUT) for distance measurement. A bimorph flexural PUT based on low-sintering piezoelectric ceramics PMN-PNN-PZT, which have high piezoelectric constant (d/sub 33/>680pC/N), high electromechanical coupling factor (K/sub p/=0.70/spl sim/0.73), was introduced. The numerical and finite element analysis (abbreviated as FEA) of its resonant modes were investigated. An advanced laser scanning vibrometer has been used to measure the displacement amplitude profiles of their resonant mode. It has greatly helped us to design and analyze transducers.
{"title":"Design and analysis of a piezoelectric ultrasonic transducer for distance measurement","authors":"Z. Gui, Xiaobing Hu, Longtu Li","doi":"10.1109/ISAF.2002.1195937","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195937","url":null,"abstract":"This paper describes a kind of bimorph flexural piezoelectric ultrasonic transducer (abbreviated as PUT) for distance measurement. A bimorph flexural PUT based on low-sintering piezoelectric ceramics PMN-PNN-PZT, which have high piezoelectric constant (d/sub 33/>680pC/N), high electromechanical coupling factor (K/sub p/=0.70/spl sim/0.73), was introduced. The numerical and finite element analysis (abbreviated as FEA) of its resonant modes were investigated. An advanced laser scanning vibrometer has been used to measure the displacement amplitude profiles of their resonant mode. It has greatly helped us to design and analyze transducers.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"39 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":"122994853","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.2002.1195916
I. Koutsaroff, P. Woo, L. Mcneil, M. Zelner, A. Kassam, M. Capanu, L. Chmiel, B. McClelland, A. Cervin-Lawry
(Ba/sub 0.7/SrO/sub 0.3/)TiO/sub 3/ (BST) double layer capacitors with Pt electrodes were fabricated under identical conditions on different substrates: SiO/sub 2//Si(111), r-plane sapphire, polycrystalline alumina Al/sub 2/O/sub 3/ (99.6%), Zirconia/Yttria Stabilized Alumina (ZYSA) and glazed polycrystalline alumina. The formation of the crystalline structure of BST films, grown by metal-organic decomposition (MOD) at various thermal processing conditions, leads to significant change in the dielectric properties of the BST films. By preparing BST films of the same thickness and under the same processing conditions, we observed that they possess higher capacitance when grown on all types of alumina-based substrates compared to those on SiO/sub 2//Si substrates. The higher capacitance on alumina were always associated with larger dissipation factors, and lower or similar leakage current densities. The final tuning of dielectric properties of BST double layer capacitors on non-silicon substrates was correlated to the processing conditions. Furthermore, the processing parameters and the type of lower electrode should be optimized individually for each specific substrate. The lowest achieved leakage current density of Pt/BST/Pt capacitor (500/spl times/500 /spl mu/m/sup 2/) on glazed alumina was 2.8/spl times/10/sup -9/ A/cm/sup 2/ at 200 kV/cm with capacitance per unit area of 27 fF//spl mu/m/sup 2/.
{"title":"Dielectric properties of (Ba,Sr)TiO/sub 3/ MOD films grown on various substrates","authors":"I. Koutsaroff, P. Woo, L. Mcneil, M. Zelner, A. Kassam, M. Capanu, L. Chmiel, B. McClelland, A. Cervin-Lawry","doi":"10.1109/ISAF.2002.1195916","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195916","url":null,"abstract":"(Ba/sub 0.7/SrO/sub 0.3/)TiO/sub 3/ (BST) double layer capacitors with Pt electrodes were fabricated under identical conditions on different substrates: SiO/sub 2//Si(111), r-plane sapphire, polycrystalline alumina Al/sub 2/O/sub 3/ (99.6%), Zirconia/Yttria Stabilized Alumina (ZYSA) and glazed polycrystalline alumina. The formation of the crystalline structure of BST films, grown by metal-organic decomposition (MOD) at various thermal processing conditions, leads to significant change in the dielectric properties of the BST films. By preparing BST films of the same thickness and under the same processing conditions, we observed that they possess higher capacitance when grown on all types of alumina-based substrates compared to those on SiO/sub 2//Si substrates. The higher capacitance on alumina were always associated with larger dissipation factors, and lower or similar leakage current densities. The final tuning of dielectric properties of BST double layer capacitors on non-silicon substrates was correlated to the processing conditions. Furthermore, the processing parameters and the type of lower electrode should be optimized individually for each specific substrate. The lowest achieved leakage current density of Pt/BST/Pt capacitor (500/spl times/500 /spl mu/m/sup 2/) on glazed alumina was 2.8/spl times/10/sup -9/ A/cm/sup 2/ at 200 kV/cm with capacitance per unit area of 27 fF//spl mu/m/sup 2/.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"98 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":"122097552","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.2002.1195923
T. Shrout, R. Eitel, C. Randall, E. Alberta, P. Rehrig
New morphotropic phase boundary (MPB) piezoelectrics with ferroelectric phase transitions (T/sub c/) exceeding that of PbZrO/sub 3/-PbTiO/sub 3/ (PZT) were investigated. Based on a perovskite tolerance factor - T/sub c/ relationship, new high T/sub c/ MPB systems were projected in Bi(Me)O/sub 3/-PbTiO/sub 3/ systems, where Me is a relatively large B/sup +3/-site cation. For the (1-x)BiScO/sub 3/-(x)PbTiO/sub 3/ solid solution, a MPB was found at x-0.64 separating the rhombohedral and tetragonal phases, with correspondingly enhanced dielectric and piezoelectric properties. A transition temperature T/sub c/ of /spl sim/450/spl deg/C was determined with higher T/sub c/s projected with lower tolerance factor systems.
{"title":"New high temperature morphotropic phase boundary piezoelectric ceramics","authors":"T. Shrout, R. Eitel, C. Randall, E. Alberta, P. Rehrig","doi":"10.1109/ISAF.2002.1195923","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195923","url":null,"abstract":"New morphotropic phase boundary (MPB) piezoelectrics with ferroelectric phase transitions (T/sub c/) exceeding that of PbZrO/sub 3/-PbTiO/sub 3/ (PZT) were investigated. Based on a perovskite tolerance factor - T/sub c/ relationship, new high T/sub c/ MPB systems were projected in Bi(Me)O/sub 3/-PbTiO/sub 3/ systems, where Me is a relatively large B/sup +3/-site cation. For the (1-x)BiScO/sub 3/-(x)PbTiO/sub 3/ solid solution, a MPB was found at x-0.64 separating the rhombohedral and tetragonal phases, with correspondingly enhanced dielectric and piezoelectric properties. A transition temperature T/sub c/ of /spl sim/450/spl deg/C was determined with higher T/sub c/s projected with lower tolerance factor systems.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"19 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":"122155252","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.2002.1195930
S. Turcu, B. Jadidian, S. Danforth, A. Safari
The design, processing conditions and electromechanical characterization of novel piezoelectric ceramic/polymer composites with 2-2 and 3-3 connectivity is presented. The ceramic structures made of PZT were prepared by Layered Manufacturing, namely by Fused Deposition of Ceramics (FDC) process. The ceramic phase in the form of fibers or sheets was oriented at different orientation angles /spl theta/ with respect to the x/sub 3/ axis of the sample, which varied between 0/spl deg/ and 75/spl deg/, in 15/spl deg/ increments. The sintered structures were placed in Spurr Epoxy polymer and diced in 2mm thickness. The electromechanical and elastic properties were investigated as a function of orientation angle /spl theta/. The longitudinal piezoelectric charge coefficient showed a decrease in the property as the /spl theta/ increases. It was found that as the orientation angle /spl theta/ was increased, the transverse piezoelectric charge coefficient d/sub 3l/ changed its sign from a negative to a positive value at /spl theta/ = 37.5/spl deg/ reaching a maximum value at 45/spl deg/ for both types of composites. Due to the contribution of a positive d/sub 3l/ coefficient, a significant increase in the hydrostatic charge coefficient was observed.
{"title":"Novel piezoelectric ceramic/polymer composite transducers","authors":"S. Turcu, B. Jadidian, S. Danforth, A. Safari","doi":"10.1109/ISAF.2002.1195930","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195930","url":null,"abstract":"The design, processing conditions and electromechanical characterization of novel piezoelectric ceramic/polymer composites with 2-2 and 3-3 connectivity is presented. The ceramic structures made of PZT were prepared by Layered Manufacturing, namely by Fused Deposition of Ceramics (FDC) process. The ceramic phase in the form of fibers or sheets was oriented at different orientation angles /spl theta/ with respect to the x/sub 3/ axis of the sample, which varied between 0/spl deg/ and 75/spl deg/, in 15/spl deg/ increments. The sintered structures were placed in Spurr Epoxy polymer and diced in 2mm thickness. The electromechanical and elastic properties were investigated as a function of orientation angle /spl theta/. The longitudinal piezoelectric charge coefficient showed a decrease in the property as the /spl theta/ increases. It was found that as the orientation angle /spl theta/ was increased, the transverse piezoelectric charge coefficient d/sub 3l/ changed its sign from a negative to a positive value at /spl theta/ = 37.5/spl deg/ reaching a maximum value at 45/spl deg/ for both types of composites. Due to the contribution of a positive d/sub 3l/ coefficient, a significant increase in the hydrostatic charge coefficient was observed.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"6 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":"128488910","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.2002.1195857
M. Biegalski, R. Thayer, J. Nino, S. Trolier-McKinstry
The optical properties and band gaps of capacitor materials are important for a number of reasons, including assessing the viability of candidate materials for gate dielectrics in semiconductors, identifying the electronic components of the polarizability, and monitoring degradation processes. This paper reports the high frequency dielectric function of several capacitor materials in the near UV to near IR range as determined by spectroscopic ellipsometry. Spectroscopic ellipsometry was also be used to determine changes in the depth profile due to changes in the dielectric function. In this work dielectric materials, primarily strontium titanate, were examined to determine their changes during DC electric field induced degradation.
{"title":"Dielectric properties of capacitor materials in the optical frequency range","authors":"M. Biegalski, R. Thayer, J. Nino, S. Trolier-McKinstry","doi":"10.1109/ISAF.2002.1195857","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195857","url":null,"abstract":"The optical properties and band gaps of capacitor materials are important for a number of reasons, including assessing the viability of candidate materials for gate dielectrics in semiconductors, identifying the electronic components of the polarizability, and monitoring degradation processes. This paper reports the high frequency dielectric function of several capacitor materials in the near UV to near IR range as determined by spectroscopic ellipsometry. Spectroscopic ellipsometry was also be used to determine changes in the depth profile due to changes in the dielectric function. In this work dielectric materials, primarily strontium titanate, were examined to determine their changes during DC electric field induced degradation.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"6 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":"126865780","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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