Pub Date : 2013-01-01DOI: 10.1080/00150193.2013.821893
S. Sanna, A. Riefer, S. Neufeld, W. Schmidt, G. Berth, A. Widhalm, A. Zrenner
The structural and vibrational properties of lithium niobate (LN) - lithium tantalate (LT) mixed crystals (LNT, LiNb1-xTaxO3) are investigated over the whole composition range by first-principles simulations. The crystal volume grows roughly linearly from LT to LN, whereby the lattice parameters a and c show minor deviations from the Vegard behavior between the end-compounds, LiNbO3 and LiTaO3. Our calculations in the framework of the density functional theory show the TO1, TO2 and TO4-modes to become harder with increasing Nb concentration. TO3 becomes softer with increasing Nb content, instead. The frequency shifts of the zone center A1-TO phonon modes for crystals with different compositions are found to be as large as 30 cm-1. Raman spectroscopy, which is sensitive to the A1 modes, can be therefore employed to determine the crystal composition.
{"title":"Vibrational fingerprints of LiNbO3-LiTaO3 mixed crystals","authors":"S. Sanna, A. Riefer, S. Neufeld, W. Schmidt, G. Berth, A. Widhalm, A. Zrenner","doi":"10.1080/00150193.2013.821893","DOIUrl":"https://doi.org/10.1080/00150193.2013.821893","url":null,"abstract":"The structural and vibrational properties of lithium niobate (LN) - lithium tantalate (LT) mixed crystals (LNT, LiNb<sub>1-x</sub>Ta<sub>x</sub>O<sub>3</sub>) are investigated over the whole composition range by first-principles simulations. The crystal volume grows roughly linearly from LT to LN, whereby the lattice parameters a and c show minor deviations from the Vegard behavior between the end-compounds, LiNbO<sub>3</sub> and LiTaO<sub>3</sub>. Our calculations in the framework of the density functional theory show the TO<sub>1</sub>, TO<sub>2</sub> and TO<sub>4</sub>-modes to become harder with increasing Nb concentration. TO<sub>3</sub> becomes softer with increasing Nb content, instead. The frequency shifts of the zone center A<sub>1</sub>-TO phonon modes for crystals with different compositions are found to be as large as 30 cm<sup>-1</sup>. Raman spectroscopy, which is sensitive to the A<sub>1</sub> modes, can be therefore employed to determine the crystal composition.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"58 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85372140","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 : 2013-01-01DOI: 10.1080/00150193.2013.822776
Sunmin Byenon, Juhyun Yoo
In this study, (1-x)[(Li0.04(Na0.56K0.44)0.96(Nb0.90Ta0.10) 0.998Zn0.005O3)]-xKNbO3 (x = 0 ~ 7.5 mol%) composition ceramics were fabricated by a conventional sintering technique. The influences of KNbO3 on the dielectric and piezoelectric properties of the ceramics were investigated. Optimum physical properties of piezoelectric constant d33 = 255 [pC/N], electromechanical coupling factor kp = 0.4358, dielectric constant εr= 699, measured density (ρ)= 4.49 [g/cm3] were obtained from the composition ceramic with x = 3[mol%]. These results indicate that the (1-x) LNKLNTZ-xKN ceramic is a promising lead-free piezoelectric candidate material for practical applications.
{"title":"Dielectric and piezoelectric properties of modified (Na, K)NbO3 ceramics substituted with KNbO3","authors":"Sunmin Byenon, Juhyun Yoo","doi":"10.1080/00150193.2013.822776","DOIUrl":"https://doi.org/10.1080/00150193.2013.822776","url":null,"abstract":"In this study, (1-x)[(Li<sub>0.04</sub>(Na<sub>0.56</sub>K<sub>0.44</sub>)<sub>0.96</sub>(Nb<sub>0.90</sub>Ta<sub>0.10</sub>) <sub>0.998</sub>Zn<sub>0.005</sub>O<sub>3</sub>)]-xKNbO<sub>3</sub> (x = 0 ~ 7.5 mol%) composition ceramics were fabricated by a conventional sintering technique. The influences of KNbO<sub>3</sub> on the dielectric and piezoelectric properties of the ceramics were investigated. Optimum physical properties of piezoelectric constant d<sub>33</sub> = 255 [pC/N], electromechanical coupling factor k<sub>p</sub> = 0.4358, dielectric constant ε<sub>r</sub>= 699, measured density (ρ)= 4.49 [g/cm<sup>3</sup>] were obtained from the composition ceramic with x = 3[mol%]. These results indicate that the (1-x) LNKLNTZ-xKN ceramic is a promising lead-free piezoelectric candidate material for practical applications.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"5 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83756967","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 : 2012-09-10DOI: 10.1109/ISAF.2012.6297843
D. Kajewski, J. Szade, J. Kubacki, K. Szot, A. Kohl, C. Lenser, R. Dittmann
Atomic Force Microscopy (AFM) measurements have been performed for Fe doped SrTiO3 thin films with an Fe concentration of 2 and 5 at%. Thin films with a thickness of about 20 nm were grown by pulsed laser deposition on single crystalline SrTi0.99Nb0.01O3 substrates. Low-energy electron diffraction examination showed that the films are single crystalline. The regions treated with the AFM tip (applied dc voltage up to 6V) showed inhomogeneity of the electrical conductivity.
{"title":"Fe valence determination in doped SrTiO3 epitaxial films","authors":"D. Kajewski, J. Szade, J. Kubacki, K. Szot, A. Kohl, C. Lenser, R. Dittmann","doi":"10.1109/ISAF.2012.6297843","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297843","url":null,"abstract":"Atomic Force Microscopy (AFM) measurements have been performed for Fe doped SrTiO3 thin films with an Fe concentration of 2 and 5 at%. Thin films with a thickness of about 20 nm were grown by pulsed laser deposition on single crystalline SrTi0.99Nb0.01O3 substrates. Low-energy electron diffraction examination showed that the films are single crystalline. The regions treated with the AFM tip (applied dc voltage up to 6V) showed inhomogeneity of the electrical conductivity.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"37 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2012-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73107519","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.2012.6297815
E. M. Alkoy, A. B. Yavuz, D. Avdan, S. Alkoy
Lead-free potassium sodium niobate (KNN) ceramics were prepared with lithium modification. Copper oxide was also added as sintering aid. Impedance spectroscopy was used as a tool to analyze electrical behavior of ceramics as a function of frequency from 100 Hz to 10 MHz at various temperatures.
{"title":"Electrical properties and impedance spectroscopy of modified potassium sodium niobate ceramics","authors":"E. M. Alkoy, A. B. Yavuz, D. Avdan, S. Alkoy","doi":"10.1109/ISAF.2012.6297815","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297815","url":null,"abstract":"Lead-free potassium sodium niobate (KNN) ceramics were prepared with lithium modification. Copper oxide was also added as sintering aid. Impedance spectroscopy was used as a tool to analyze electrical behavior of ceramics as a function of frequency from 100 Hz to 10 MHz at various temperatures.","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":"78392167","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.2012.6297740
M. Kadota, T. Ogami, T. Kimura
Currently, an ultra wide band resonator to realize a tunable filter with a wide tunable range is strongly required, because a mobile phone with multi-bands and a cognitive radio system require such tunable filters to simplify their circuits. This time, authors realized resonators with ultra wide bandwidths of 26 to 29 % and a large impedance ratio of 92 to 98 dB between resonant and anti-resonant frequencies using an SH0 plate wave in a LiNbO3 plate. In addition, a band pass type tunable filter with a tunable range of 16 to 18 % was realized using the resonators.
{"title":"Ultra wide band elastic resonators and their application: SH0 mode plate wave resonators with ultra wide bandwidth of 29 %","authors":"M. Kadota, T. Ogami, T. Kimura","doi":"10.1109/ISAF.2012.6297740","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297740","url":null,"abstract":"Currently, an ultra wide band resonator to realize a tunable filter with a wide tunable range is strongly required, because a mobile phone with multi-bands and a cognitive radio system require such tunable filters to simplify their circuits. This time, authors realized resonators with ultra wide bandwidths of 26 to 29 % and a large impedance ratio of 92 to 98 dB between resonant and anti-resonant frequencies using an SH0 plate wave in a LiNbO3 plate. In addition, a band pass type tunable filter with a tunable range of 16 to 18 % was realized using the resonators.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"1 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":"77888026","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.2012.6297864
S. Gebhardt, M. Flossel, A. Schonecker, U. Lieske, T. Klesse
Structural Health Monitoring (SHM) systems allow for permanent and online characterization of condition and health of structural components. We introduce novel SHM modules fully based on inorganic materials which show a distinguished improve of temperature and chemical stability compared to known piezoceramic-polymer-patches. Using ceramic multilayer technology lead zirconate titanate (PZT) discs are integrated into a package of low temperature cofired ceramic (LTCC) sheets enabling for the production of compact ultrasonic transducers with integrated electronic circuits and signal processing units.
{"title":"Robust structural health monitoring transducers based on LTCC/PZT multilayer","authors":"S. Gebhardt, M. Flossel, A. Schonecker, U. Lieske, T. Klesse","doi":"10.1109/ISAF.2012.6297864","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297864","url":null,"abstract":"Structural Health Monitoring (SHM) systems allow for permanent and online characterization of condition and health of structural components. We introduce novel SHM modules fully based on inorganic materials which show a distinguished improve of temperature and chemical stability compared to known piezoceramic-polymer-patches. Using ceramic multilayer technology lead zirconate titanate (PZT) discs are integrated into a package of low temperature cofired ceramic (LTCC) sheets enabling for the production of compact ultrasonic transducers with integrated electronic circuits and signal processing units.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"10 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":"81852284","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.2012.6297799
H. Takeda, H. Akutsu, M. Zubair, T. Hoshina, T. Tsurumi
We report synthesis of BaTiO3-(Bi1/2Na1/2)TiO3 (BT-BNT) semiconducting ceramics by conventional solid-state reaction method in air atmosphere. By adding CaO into the calcined BT-BNT powder, the resulting ceramics acquires the semiconductivity with the resistivity at room temperature ρRT value of 102-103 Ωcm and PTC behavior. The structure analysis using X-ray diffraction method, it was found that the CaO added BT-BNT ceramics consisted of perovskite-type ABO3 single phase. Chemical composition analysis by inductively coupled plasma spectrometry disclosed a distinct evaporation of Na and Bi during sintering process. The quantity of evaporation of Na was higher than that of Bi. Based on these results, it was suggested that dominant substitution of Ca2+ for Na+ in the A site occurred, and then that part of Bi3+ separated from divalent (Bi1/2Na1/2)2+ pairs worked as a donor.
{"title":"Semiconducting behavior of CaO-added BaTiO3-(Bi1/2Na1/2)TiO3 solid solution ceramics","authors":"H. Takeda, H. Akutsu, M. Zubair, T. Hoshina, T. Tsurumi","doi":"10.1109/ISAF.2012.6297799","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297799","url":null,"abstract":"We report synthesis of BaTiO<sub>3</sub>-(Bi<sub>1/2</sub>Na<sub>1/2</sub>)TiO<sub>3</sub> (BT-BNT) semiconducting ceramics by conventional solid-state reaction method in air atmosphere. By adding CaO into the calcined BT-BNT powder, the resulting ceramics acquires the semiconductivity with the resistivity at room temperature ρ<sub>RT</sub> value of 10<sup>2</sup>-10<sup>3</sup> Ωcm and PTC behavior. The structure analysis using X-ray diffraction method, it was found that the CaO added BT-BNT ceramics consisted of perovskite-type ABO<sub>3</sub> single phase. Chemical composition analysis by inductively coupled plasma spectrometry disclosed a distinct evaporation of Na and Bi during sintering process. The quantity of evaporation of Na was higher than that of Bi. Based on these results, it was suggested that dominant substitution of Ca<sup>2+</sup> for Na<sup>+</sup> in the A site occurred, and then that part of Bi<sup>3+</sup> separated from divalent (Bi<sub>1/2</sub>Na<sub>1/2</sub>)<sup>2+</sup> pairs worked as a donor.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"9 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":"84306988","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.2012.6297773
A. Kikuchihara, T. Kimura
The development of grain orientation was examined for (K, Na)NbO3-based ceramics using two kinds of platelike NaNbO3 template powders made by single- and two-step molten salt synthesis (MSS) and four kinds of matrix powders to examine the factors controlling the degree of orientation. The template grains made by single-step MSS were dissolved in the matrix of a mixture of NaNbO3 and KNbO3 powders, leaving large voids. The template grains made by two-step MSS were not dissolved and gave high reproducibility in the degree of orientation. The effect of matrix species on the grain orientation was examined using the template powder made by two-step MSS and the matrixes of KNbO3, NaNbO3, and (K0.5Na0.5)NbO3 powders and a mixture of KNbO3 and NaNbO3 powders. The extensive grain orientation developed only in (K0.5Na0.5)NbO3 and a mixture of KNbO3 and NaNbO3 powders. The origin of the difference in the grain orientation behavior was examined by microstructure observation.
{"title":"Mechanism of texture development in <001> oriented (K, Na)NbO3-based ceramics","authors":"A. Kikuchihara, T. Kimura","doi":"10.1109/ISAF.2012.6297773","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297773","url":null,"abstract":"The development of grain orientation was examined for (K, Na)NbO<sub>3</sub>-based ceramics using two kinds of platelike NaNbO<sub>3</sub> template powders made by single- and two-step molten salt synthesis (MSS) and four kinds of matrix powders to examine the factors controlling the degree of orientation. The template grains made by single-step MSS were dissolved in the matrix of a mixture of NaNbO<sub>3</sub> and KNbO<sub>3</sub> powders, leaving large voids. The template grains made by two-step MSS were not dissolved and gave high reproducibility in the degree of orientation. The effect of matrix species on the grain orientation was examined using the template powder made by two-step MSS and the matrixes of KNbO<sub>3</sub>, NaNbO<sub>3</sub>, and (K<sub>0.5</sub>Na<sub>0.5</sub>)NbO<sub>3</sub> powders and a mixture of KNbO<sub>3</sub> and NaNbO<sub>3</sub> powders. The extensive grain orientation developed only in (K<sub>0.5</sub>Na<sub>0.5</sub>)NbO<sub>3</sub> and a mixture of KNbO<sub>3</sub> and NaNbO<sub>3</sub> powders. The origin of the difference in the grain orientation behavior was examined by microstructure observation.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"3 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":"76849169","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.2012.6297734
M. Bazzan, M. Ciampolillo, A. Zaltron, N. Argiolas, C. Sada, N. Kokanian, Marc D. Fontana
Local doping by Fe in-diffusion in lithium niobate is a powerful technique to create regions of high photorefractive sensitivity useful to fabricate holographic optical elements such as filters, demultiplexers, Bragg mirrors and so on. In this paper the fabrication and characterization of such regions are reviewed, giving practical advices about how to proceed to realize such areas with the required characteristics.
{"title":"Fabrication and characterization of photorefractive platforms in lithium niobate for recording of integrated holographic devices","authors":"M. Bazzan, M. Ciampolillo, A. Zaltron, N. Argiolas, C. Sada, N. Kokanian, Marc D. Fontana","doi":"10.1109/ISAF.2012.6297734","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297734","url":null,"abstract":"Local doping by Fe in-diffusion in lithium niobate is a powerful technique to create regions of high photorefractive sensitivity useful to fabricate holographic optical elements such as filters, demultiplexers, Bragg mirrors and so on. In this paper the fabrication and characterization of such regions are reviewed, giving practical advices about how to proceed to realize such areas with the required characteristics.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"11 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":"84033869","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.2012.6297777
A. Kleiner, G. Suchaneck, B. Adolphi, G. Gerlach, V. Lavrentiev, Z. Hubička, M. Čada, L. Jastrabík, A. Dejneka
In this work, we investigate the composition profile of nanocrystalline Pb(Zr, Ti)O3 (PZT) thin films deposited by means of reactive magnetron sputtering from 200 mm diameter metallic targets (Pb, Ti, Zr). High-power pulse sputtering has been employed for alternatively the Zr- or Ti-target. Composition analysis and profiling was performed by means of X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering (RBS). RBS data was recalibrated to exclude hydrogen content not determined by XPS. Advantages and drawbacks of both methods for PZT composition profiling are discussed.
{"title":"Composition profiling of piezoelectric PZT thin films deposited onto Cu coated polymer substrates","authors":"A. Kleiner, G. Suchaneck, B. Adolphi, G. Gerlach, V. Lavrentiev, Z. Hubička, M. Čada, L. Jastrabík, A. Dejneka","doi":"10.1109/ISAF.2012.6297777","DOIUrl":"https://doi.org/10.1109/ISAF.2012.6297777","url":null,"abstract":"In this work, we investigate the composition profile of nanocrystalline Pb(Zr, Ti)O3 (PZT) thin films deposited by means of reactive magnetron sputtering from 200 mm diameter metallic targets (Pb, Ti, Zr). High-power pulse sputtering has been employed for alternatively the Zr- or Ti-target. Composition analysis and profiling was performed by means of X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering (RBS). RBS data was recalibrated to exclude hydrogen content not determined by XPS. Advantages and drawbacks of both methods for PZT composition profiling are discussed.","PeriodicalId":20497,"journal":{"name":"Proceedings of ISAF-ECAPD-PFM 2012","volume":"56 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":"82177871","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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