Pub Date : 2012-07-09DOI: 10.1109/ISAF.2012.6297831
P. Bednyakov, N. Setter, D. Rytz
Dielectric properties of K(Ta0,53Nb0,47)O3 [KTN] single crystals with <;100>; and <;011>; crystallographic orientation were studied. Temperature dependencies of dielectric permittivity of monodomain and polydomain crystals of these orientations are compared.
{"title":"Dielectric properties of K(Ta0.53Nb0.47)O3 single crystal","authors":"P. Bednyakov, N. Setter, D. Rytz","doi":"10.1109/ISAF.2012.6297831","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297831","url":null,"abstract":"Dielectric properties of K(Ta<sub>0,53</sub>Nb<sub>0,47</sub>)O<sub>3</sub> [KTN] single crystals with <;100>; and <;011>; crystallographic orientation were studied. Temperature dependencies of dielectric permittivity of monodomain and polydomain crystals of these orientations are compared.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"60 3 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77410324","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297761
H. Jung, K. H. Baek, S. Hidaka, D. Song, Se Bin Kim, T. Sung
Two models for energy harvesting system imparting rotational energy to piezoelectric materials are presented in order to compare the effects of applying identical amounts of energy to a cantilever beam by strain-changing and shock application. For a piezoelectric system given a high impulse with low displacement, higher power outputs were generated at lower resistive loads. Conversely, for a system with high displacement at a low impulse, power output was higher at high resistive loads. At matched impedance, the secondary shock system generated higher power output than the hitting system did at low resistive load. Optimized response of secondary shock system was obtained at a frequency of 60 Hz with a low resistive load of 1 k Ω. The generated output power was measured 124 mW, which corresponds to power density of 140 mW/cm3 for entire cantilever beam and power density of 342 mW/cm3 for only piezoelectric material volume. For a system without a secondary impulse at low resistive loads (1 k Ω), the optimizing frequency was between 20 and 30 Hz, with an output power of 22 mW, which corresponds to a 25 mW/cm3 power density for entire cantilever beam and power density of 60 mW/ cm3 for only piezoelectric material volume.
为了比较在悬臂梁上施加相同能量时的应变变化效应和冲击效应，提出了两种传递旋转能量给压电材料的能量收集系统模型。对于给定高脉冲、低位移的压电系统，在低阻性负载下产生较高的输出功率。相反，对于一个在低脉冲下具有高位移的系统，在高电阻负载下输出功率更高。在阻抗匹配时，二次冲击系统比低阻负载下的冲击系统产生更高的功率输出。二次冲击系统在频率为60 Hz、低电阻负载为1 k Ω时的响应得到了优化。测量产生的输出功率为124 mW，对应于整个悬臂梁的功率密度为140 mW/cm3，仅压电材料体积的功率密度为342 mW/cm3。对于低阻性负载(1 k Ω)下无二次脉冲的系统，优化频率在20至30 Hz之间，输出功率为22 mW，对应于整个悬臂梁的功率密度为25 mW/cm3，仅压电材料体积的功率密度为60 mW/cm3。
{"title":"Design and optimization of secondary shock type piezoelectric system","authors":"H. Jung, K. H. Baek, S. Hidaka, D. Song, Se Bin Kim, T. Sung","doi":"10.1109/ISAF.2012.6297761","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297761","url":null,"abstract":"Two models for energy harvesting system imparting rotational energy to piezoelectric materials are presented in order to compare the effects of applying identical amounts of energy to a cantilever beam by strain-changing and shock application. For a piezoelectric system given a high impulse with low displacement, higher power outputs were generated at lower resistive loads. Conversely, for a system with high displacement at a low impulse, power output was higher at high resistive loads. At matched impedance, the secondary shock system generated higher power output than the hitting system did at low resistive load. Optimized response of secondary shock system was obtained at a frequency of 60 Hz with a low resistive load of 1 k Ω. The generated output power was measured 124 mW, which corresponds to power density of 140 mW/cm3 for entire cantilever beam and power density of 342 mW/cm3 for only piezoelectric material volume. For a system without a secondary impulse at low resistive loads (1 k Ω), the optimizing frequency was between 20 and 30 Hz, with an output power of 22 mW, which corresponds to a 25 mW/cm3 power density for entire cantilever beam and power density of 60 mW/ cm3 for only piezoelectric material volume.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"48 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73370096","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297769
H. Funakubo, S. Yasui, K. Yazawa, J. Nagata, T. Oikawa, T. Yamada, H. Uchida
We developed the piezoelectric materials not including Pb, Li, K and Na as constituent elements. Our concern is the composition survey of the morphotropic phase boundary between tetragonal and non-tetragonal ferroelectric materials. In this approach, we must select the tetragonal ferroelectrics other than PbTiO3 and (Bi1/2K1/2)TiO3 as a end material. BiCoO3 and Bi(Zn1/2Ti1/2)O3 are novel tetragonal candidates for this purpose. We successfully grew epitaxial tetragonal films having ferroelectricity in BiCoO3-BiFeO3 and Bi(Zn1/2Ti1/2)O3-BiFeO3 systems. Based on these system, composition having maximum piezoelectric response of d33(AFM) = 280 pm/V was discovered for epitaxial films in Bi(Zn1/2Ti1/2)O3-Bi(Mg1/2Ti1/2)O3-BiFeO3 system.
{"title":"Development of novel Pb, Li, Na and K-free piezoelectric materials for Si-based MEMS application","authors":"H. Funakubo, S. Yasui, K. Yazawa, J. Nagata, T. Oikawa, T. Yamada, H. Uchida","doi":"10.1109/ISAF.2012.6297769","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297769","url":null,"abstract":"We developed the piezoelectric materials not including Pb, Li, K and Na as constituent elements. Our concern is the composition survey of the morphotropic phase boundary between tetragonal and non-tetragonal ferroelectric materials. In this approach, we must select the tetragonal ferroelectrics other than PbTiO<sub>3</sub> and (Bi<sub>1/2</sub>K<sub>1/2</sub>)TiO<sub>3</sub> as a end material. BiCoO<sub>3</sub> and Bi(Zn<sub>1/2</sub>Ti<sub>1/2</sub>)O<sub>3</sub> are novel tetragonal candidates for this purpose. We successfully grew epitaxial tetragonal films having ferroelectricity in BiCoO<sub>3</sub>-BiFeO<sub>3</sub> and Bi(Zn<sub>1/2</sub>Ti<sub>1/2</sub>)O<sub>3</sub>-BiFeO<sub>3</sub> systems. Based on these system, composition having maximum piezoelectric response of d<sub>33(AFM)</sub> = 280 pm/V was discovered for epitaxial films in Bi(Zn<sub>1/2</sub>Ti<sub>1/2</sub>)O<sub>3</sub>-Bi(Mg<sub>1/2</sub>Ti<sub>1/2</sub>)O<sub>3</sub>-BiFeO<sub>3</sub> system.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"23 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83635841","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297782
R. Rivera, M. Hejazi, A. Safari
BiFeO3 (BFO) has stimulated a great interest in recent years for its room temperature multiferroic behavior with very high remnant polarization. However, the leakage current of BFO films is very high. To lower the leakage current, we have developed thin films with following target compositions on SrRuO3 buffered on SrTiO3 substrate by Pulsed Laser Deposition (PLD): (A) BiFeO3, (B) 0.88Bi0.5Na0.5TiO3-0.08Bi0.5K0.5TiO3-0.04BaTiO3, (C) 0.6BiFeO3-0.4(Bi0.5K0.5TiO3) The phase, growth orientation, microstructural characterization and electrical properties were investigated as a function of deposition parameters. The epitaxial bi-layered 300nm BNT-BKT-BT/BFO thin films (150nm each) exhibited ferroelectric behavior as: 2Pr = 44.0 μC.cm-2, 2Ec = 200 kV.cm-1 and K = 140. Thin films with a composition of 0.6BFO-0.4BKT have also been deposited with different oxygen pressures of 300-500 mTorr. Preliminary results of 0.6BFO-0.4BKT films show that the leakage current can be suppressed by about 4 orders of magnitude which in turn improves the ferroelectric and dielectric properties of the films. It is observed that the remnant polarization increases from 8 to 19 μC.cm-2 as the oxygen pressure is changed from 500 to 300mtorr.
{"title":"Ferroelectric and dielectric properties of bismuth ferrite based thin films by Pulsed Laser Deposition","authors":"R. Rivera, M. Hejazi, A. Safari","doi":"10.1109/ISAF.2012.6297782","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297782","url":null,"abstract":"BiFeO<sub>3</sub> (BFO) has stimulated a great interest in recent years for its room temperature multiferroic behavior with very high remnant polarization. However, the leakage current of BFO films is very high. To lower the leakage current, we have developed thin films with following target compositions on SrRuO<sub>3</sub> buffered on SrTiO<sub>3</sub> substrate by Pulsed Laser Deposition (PLD): (A) BiFeO<sub>3</sub>, (B) 0.88Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub>-0.08Bi<sub>0.5</sub>K<sub>0.5</sub>TiO<sub>3</sub>-0.04BaTiO<sub>3</sub>, (C) 0.6BiFeO<sub>3</sub>-0.4(Bi<sub>0.5</sub>K<sub>0.5</sub>TiO<sub>3</sub>) The phase, growth orientation, microstructural characterization and electrical properties were investigated as a function of deposition parameters. The epitaxial bi-layered 300nm BNT-BKT-BT/BFO thin films (150nm each) exhibited ferroelectric behavior as: 2P<sub>r</sub> = 44.0 μC.cm<sup>-2</sup>, 2E<sub>c</sub> = 200 kV.cm<sup>-1</sup> and K = 140. Thin films with a composition of 0.6BFO-0.4BKT have also been deposited with different oxygen pressures of 300-500 mTorr. Preliminary results of 0.6BFO-0.4BKT films show that the leakage current can be suppressed by about 4 orders of magnitude which in turn improves the ferroelectric and dielectric properties of the films. It is observed that the remnant polarization increases from 8 to 19 μC.cm<sup>-2</sup> as the oxygen pressure is changed from 500 to 300mtorr.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"74 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86299301","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297741
Yi-Ying Lai, Chih-Kung Lee, Wen-Jong Wu
The main purpose of this paper is to compare three different topologies of LED drivers by using a piezoelectric transformer. The advantages of LEDs lighting applications include small size, low power consumption and high efficacy. On the other hand, the merits of the piezoelectric transformer are thin profile, high power density and no electromagnetic interference radiation unlike conventional electromagnetic transformers. Therefore, piezoelectric transformers are suitable to drive LEDs. Since the output voltage of a piezoelectric transformer is highly related to the load impedance, the type of the connection between the piezoelectric transformer and LEDs is a key design parameters as it influences temperature rise and efficiency. In this paper, three different types of connections in driving LEDs are discussed in detail. They are LED self-rectifier, full-wave rectifier and current doubler. Theoretical analysis of these three various topologies are discussed. The theoretical predictions were verified by the circuit simulator PSIM. The characteristics of the three driving methods are compared and summarized.
{"title":"Comparison of three different topologies of driving LEDs with a piezoelectric transformer","authors":"Yi-Ying Lai, Chih-Kung Lee, Wen-Jong Wu","doi":"10.1109/ISAF.2012.6297741","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297741","url":null,"abstract":"The main purpose of this paper is to compare three different topologies of LED drivers by using a piezoelectric transformer. The advantages of LEDs lighting applications include small size, low power consumption and high efficacy. On the other hand, the merits of the piezoelectric transformer are thin profile, high power density and no electromagnetic interference radiation unlike conventional electromagnetic transformers. Therefore, piezoelectric transformers are suitable to drive LEDs. Since the output voltage of a piezoelectric transformer is highly related to the load impedance, the type of the connection between the piezoelectric transformer and LEDs is a key design parameters as it influences temperature rise and efficiency. In this paper, three different types of connections in driving LEDs are discussed in detail. They are LED self-rectifier, full-wave rectifier and current doubler. Theoretical analysis of these three various topologies are discussed. The theoretical predictions were verified by the circuit simulator PSIM. The characteristics of the three driving methods are compared and summarized.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"45 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85681267","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297728
Yih-Chien Chen, Ming-De Chen
The microwave dielectric properties of La(Mg0.5-xSrxSn0.5)O3 ceramics were examined with a view to their exploitation for wireless communications. The La(Mg0.5-xSrxSn0.5)O3 ceramics were prepared by the conventional solid-state method with various sintering temperatures. The La(Mg0.5-xSrxSn0.5)O3 ceramics contained La2O3. An apparent density of 6.56 g/cm3, a dielectric constant (ϵr) of 20.5, a quality factor (Q × f) of 107,900 GHz, and a temperature coefficient of resonant frequency (τf) of -84 ppm/°C were obtained for La(Mg0.4Sr0.1Sn0.5)O3 ceramics that were sintered at 1500 °C for 4 h.
{"title":"Microwave dielectric properties of novel ceramic for application in wireless communications","authors":"Yih-Chien Chen, Ming-De Chen","doi":"10.1109/ISAF.2012.6297728","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297728","url":null,"abstract":"The microwave dielectric properties of La(Mg<sub>0.5-x</sub>Sr<sub>x</sub>Sn<sub>0.5</sub>)O<sub>3</sub> ceramics were examined with a view to their exploitation for wireless communications. The La(Mg<sub>0.5-x</sub>Sr<sub>x</sub>Sn<sub>0.5</sub>)O<sub>3</sub> ceramics were prepared by the conventional solid-state method with various sintering temperatures. The La(Mg<sub>0.5-x</sub>Sr<sub>x</sub>Sn<sub>0.5</sub>)O<sub>3</sub> ceramics contained La<sub>2</sub>O<sub>3</sub>. An apparent density of 6.56 g/cm<sup>3</sup>, a dielectric constant (ϵ<sub>r</sub>) of 20.5, a quality factor (Q × f) of 107,900 GHz, and a temperature coefficient of resonant frequency (τ<sub>f</sub>) of -84 ppm/°C were obtained for La(Mg<sub>0.4</sub>Sr<sub>0.1</sub>Sn<sub>0.5</sub>)O<sub>3</sub> ceramics that were sintered at 1500 °C for 4 h.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"93 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86673019","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297757
J. Kulawk, D. Szwagierczak, B. Synkiewicz
The nonferroelectric high-permittivity material CaCu3Ti4O12, being a naturally formed internal barrier layer capacitor, was utilized for preparation of slurries for tape casting and fabrication of multilayer ceramic capacitors. Screen printed silver or silver-palladium electrodes were co-fired with ceramic green sheets at 940°C. The dielectric properties of the CaCu3Ti4O12-based multilayer capacitors were studied in a wide frequency range of 0.1 Hz-2 MHz and in the temperature range from -55 to 400°C. The dominant response which is recorded at low frequency range and at temperatures above 150°C is related to grain boundaries. The dielectric response at low temperatures and/or high frequencies is attributed to grains. SEM and EDS studies showed heterogeneous microstructure and composition of ceramic layers. Large grains have composition close to stoichiometric CCTO, while smaller grains and grain boundaries regions are enriched in oxygen and depleted in copper. The fabricated multilayer capacitors exhibit low sintering temperature suitable for use of cheap electrodes, good compatibility of ceramic layers with the applied commercial conductive pastes, high specific capacitance and a relatively low temperature coefficient of capacitance.
{"title":"Multilayer ceramic capacitors with CaCu3Ti4O12 dielectric","authors":"J. Kulawk, D. Szwagierczak, B. Synkiewicz","doi":"10.1109/ISAF.2012.6297757","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297757","url":null,"abstract":"The nonferroelectric high-permittivity material CaCu3Ti4O12, being a naturally formed internal barrier layer capacitor, was utilized for preparation of slurries for tape casting and fabrication of multilayer ceramic capacitors. Screen printed silver or silver-palladium electrodes were co-fired with ceramic green sheets at 940°C. The dielectric properties of the CaCu3Ti4O12-based multilayer capacitors were studied in a wide frequency range of 0.1 Hz-2 MHz and in the temperature range from -55 to 400°C. The dominant response which is recorded at low frequency range and at temperatures above 150°C is related to grain boundaries. The dielectric response at low temperatures and/or high frequencies is attributed to grains. SEM and EDS studies showed heterogeneous microstructure and composition of ceramic layers. Large grains have composition close to stoichiometric CCTO, while smaller grains and grain boundaries regions are enriched in oxygen and depleted in copper. The fabricated multilayer capacitors exhibit low sintering temperature suitable for use of cheap electrodes, good compatibility of ceramic layers with the applied commercial conductive pastes, high specific capacitance and a relatively low temperature coefficient of capacitance.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"5 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83502994","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297821
B. Fraygola, J. Eiras
Multiferroic solid solutions between Pb(Fe2/3W1/3)O3 (PFW) and PbTiO3 (PT) [PFW-PT] have been characterized by anelastic measurements. Anomalies in the temperature dependence of the elastic constants have been observed at TN and TC for all samples, indicating that the magnetoelectric coupling (ME) between the ferroelectric and antiferromagnetic orders occurs “via strain”. A numerical approximation for the ME coefficients was obtained from the eletroelastic and magnetoelastic coefficients and the values of electric and magnetic susceptibility. These coefficients are greater the closer the temperatures of AFM and FE orders are with each other.
{"title":"Intrinsic magnetoelectric coupling in PFW-PT solid solutions","authors":"B. Fraygola, J. Eiras","doi":"10.1109/ISAF.2012.6297821","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297821","url":null,"abstract":"Multiferroic solid solutions between Pb(Fe<sub>2/3</sub>W<sub>1/3</sub>)O<sub>3</sub> (PFW) and PbTiO<sub>3</sub> (PT) [PFW-PT] have been characterized by anelastic measurements. Anomalies in the temperature dependence of the elastic constants have been observed at T<sub>N</sub> and T<sub>C</sub> for all samples, indicating that the magnetoelectric coupling (ME) between the ferroelectric and antiferromagnetic orders occurs “via strain”. A numerical approximation for the ME coefficients was obtained from the eletroelastic and magnetoelastic coefficients and the values of electric and magnetic susceptibility. These coefficients are greater the closer the temperatures of AFM and FE orders are with each other.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"63 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83957279","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297727
Y. Genenko, O. Hirsch, P. Erhart
Electric depolarization fields generated by a stripe domain structure in ferroelectrics are considered within a semiconductor model. Field screening due to electronic band bending and due to presence of intrinsic defects leads to the building of asymmetric space charge regions near the grain boundary. This in turn results in the formation of a potential barrier between the grain surface and its interior.
{"title":"Potential barrier at the ferroelectric grain boundary due to asymmetric screening of depolarization fields","authors":"Y. Genenko, O. Hirsch, P. Erhart","doi":"10.1109/ISAF.2012.6297727","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297727","url":null,"abstract":"Electric depolarization fields generated by a stripe domain structure in ferroelectrics are considered within a semiconductor model. Field screening due to electronic band bending and due to presence of intrinsic defects leads to the building of asymmetric space charge regions near the grain boundary. This in turn results in the formation of a potential barrier between the grain surface and its interior.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"9 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84248420","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 : 2012-07-09DOI: 10.1109/ISAF.2012.6297846
K. Ujimoto, T. Yoshimura, N. Fujimura
Crystal structure and microstructure such as surface morphology and ferroelectric domain structure of 0.2- to 2.0-μm-thick BiFeO3 epitaxial films deposited between 400 and 700°C were evaluated. For the films deposited at 500°C, tetragonal BiFeO3 was grown The relaxation of the lattice strain drastically occurred by increasing the film thickness. On the other hand, rhombohedral BiFeO3 with tetragonal distortion was grown and the relaxation of the lattice strain occurred by the grain growth for the films deposited at 650°C. The grains consist of single domain for the films deposited at 500°C, while those of films deposited at 650°C consist of multi domains. It is suggested that the domain walls existing inside the grains contributes the piezoelectric response.
{"title":"Growth temperature and thickness dependences of crystal and micro domain structures of BiFeO3 epitaxial films","authors":"K. Ujimoto, T. Yoshimura, N. Fujimura","doi":"10.1109/ISAF.2012.6297846","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297846","url":null,"abstract":"Crystal structure and microstructure such as surface morphology and ferroelectric domain structure of 0.2- to 2.0-μm-thick BiFeO3 epitaxial films deposited between 400 and 700°C were evaluated. For the films deposited at 500°C, tetragonal BiFeO3 was grown The relaxation of the lattice strain drastically occurred by increasing the film thickness. On the other hand, rhombohedral BiFeO3 with tetragonal distortion was grown and the relaxation of the lattice strain occurred by the grain growth for the films deposited at 650°C. The grains consist of single domain for the films deposited at 500°C, while those of films deposited at 650°C consist of multi domains. It is suggested that the domain walls existing inside the grains contributes the piezoelectric response.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"1999 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2012-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89929509","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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