Pub Date : 2002-05-28DOI: 10.1109/ISAF.2002.1195860
A. Bell, E. Furman
A thermodynamic model is proposed to account for the monoclinic phase observed in the solid solution system Pb(Zr/sub 1-x/Ti/sub x/)O/sub 3/. The free energy comprises three sets of terms: two expansions of polarization, one representing each of the end-members, weighted linearly with respect to composition, and terms representing the coupling between the two contributions. Employing previously published coefficients for PbTiO/sub 3/ and values extrapolated from Zr-rich PZT compositions for PbZrO/sub 3/, calculations predict the composition of the morphotropic phase boundary between the rhombohedral and tetragonal phases lies at x=0.45 and is virtually independent of temperature and the strength of coupling between the two order parameters. The range of existence of the monoclinic phase depends upon the strength of the coupling, but in general, is broadest at low temperature.
{"title":"An alternative thermodynamic model for PZT","authors":"A. Bell, E. Furman","doi":"10.1109/ISAF.2002.1195860","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195860","url":null,"abstract":"A thermodynamic model is proposed to account for the monoclinic phase observed in the solid solution system Pb(Zr/sub 1-x/Ti/sub x/)O/sub 3/. The free energy comprises three sets of terms: two expansions of polarization, one representing each of the end-members, weighted linearly with respect to composition, and terms representing the coupling between the two contributions. Employing previously published coefficients for PbTiO/sub 3/ and values extrapolated from Zr-rich PZT compositions for PbZrO/sub 3/, calculations predict the composition of the morphotropic phase boundary between the rhombohedral and tetragonal phases lies at x=0.45 and is virtually independent of temperature and the strength of coupling between the two order parameters. The range of existence of the monoclinic phase depends upon the strength of the coupling, but in general, is broadest at low temperature.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"31 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":"121438945","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.2002.1195933
P. Gonnard, L. Petit
A method for characterizing the nonlinear electromechanical coefficients and losses using measurements at low frequency and at resonance frequency is proposed. Then an electrical equivalent circuit synthesizing the whole nonlinearities is built up : it includes two components (a reactance and a resistance), which are dependent on the amplitude of the electric displacement, connected at the input of the low level Mason equivalent circuit. Applying such a circuit on piezoceramics or transducers driven at high power confirms that better performances are achieved near the antiresonance frequency. Physical interpretation is based on conflicting influences of electric field and vibration velocity on the motion of the non 180 domain walls.
{"title":"Nonlinear characterization of high power transducers","authors":"P. Gonnard, L. Petit","doi":"10.1109/ISAF.2002.1195933","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195933","url":null,"abstract":"A method for characterizing the nonlinear electromechanical coefficients and losses using measurements at low frequency and at resonance frequency is proposed. Then an electrical equivalent circuit synthesizing the whole nonlinearities is built up : it includes two components (a reactance and a resistance), which are dependent on the amplitude of the electric displacement, connected at the input of the low level Mason equivalent circuit. Applying such a circuit on piezoceramics or transducers driven at high power confirms that better performances are achieved near the antiresonance frequency. Physical interpretation is based on conflicting influences of electric field and vibration velocity on the motion of the non 180 domain walls.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"95 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":"117079246","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.2002.1195951
S. Wada, K. Muraoka, H. Kakemoto, H. Kumagai, T. Tsurumi
Piezoelectric properties of potassium niobate (KNbO/sub 3/) crystals with the single-domain state were investigated. KNbO/sub 3/ crystals were cut, polished and sized into various shapes. The mechanical processing induced mechanical damage into the crystals. Remove of the stressed surface layers was very effective to achieve high mechanical quality factor (Q/sub m/). After this treatment, KNbO/sub 3/ crystals were poled by the 2-step poling method. As a result, the domain state was almost single-domain. Using poled KNbO/sub 3/ single-domain crystals, the piezoelectric properties with k/sub 32/ modes were measured using a conventional resonance method. As a result, the [001]/sub o/ poled KNbO/sub 3/ crystals exhibited the electromechanical coupling factor (k/sub 32/) of almost 40%, the piezoelectric constant (d/sub 32/) of almost 18.5 pC/N, the dielectric constant (/spl epsiv//sub 33/) of almost 48 and Q/sub m/ over 7,600. Thus, the KNbO/sub 3/ crystals are piezoelectrics with low dielectric constants and high electromechanical coupling properties, i.e., KNbO/sub 3/ crystal is a promising material for sensor application.
{"title":"Potassium niobate single-domain crystals as piezoelectrics with low dielectric constants and high electromechanical coupling properties","authors":"S. Wada, K. Muraoka, H. Kakemoto, H. Kumagai, T. Tsurumi","doi":"10.1109/ISAF.2002.1195951","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195951","url":null,"abstract":"Piezoelectric properties of potassium niobate (KNbO/sub 3/) crystals with the single-domain state were investigated. KNbO/sub 3/ crystals were cut, polished and sized into various shapes. The mechanical processing induced mechanical damage into the crystals. Remove of the stressed surface layers was very effective to achieve high mechanical quality factor (Q/sub m/). After this treatment, KNbO/sub 3/ crystals were poled by the 2-step poling method. As a result, the domain state was almost single-domain. Using poled KNbO/sub 3/ single-domain crystals, the piezoelectric properties with k/sub 32/ modes were measured using a conventional resonance method. As a result, the [001]/sub o/ poled KNbO/sub 3/ crystals exhibited the electromechanical coupling factor (k/sub 32/) of almost 40%, the piezoelectric constant (d/sub 32/) of almost 18.5 pC/N, the dielectric constant (/spl epsiv//sub 33/) of almost 48 and Q/sub m/ over 7,600. Thus, the KNbO/sub 3/ crystals are piezoelectrics with low dielectric constants and high electromechanical coupling properties, i.e., KNbO/sub 3/ crystal is a promising material for sensor application.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131175684","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.2002.1195859
D. Viehland, J. Li
Polarization reversal and domain dynamics have been investigated in 0.7Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-0.3PbTiO/sub 3/ using a method of current transients. Investigations were performed as a function of applied electric field. The kinetics of the transients have been modeled to a stretched exponential type function. We believe that nucleation of polar clusters with a reversed polarization occurs under applied field in the vicinity of randomly quenched defects.
{"title":"A random-field model for ferroelectric domain dynamics: analysis by stretched exponential functions","authors":"D. Viehland, J. Li","doi":"10.1109/ISAF.2002.1195859","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195859","url":null,"abstract":"Polarization reversal and domain dynamics have been investigated in 0.7Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-0.3PbTiO/sub 3/ using a method of current transients. Investigations were performed as a function of applied electric field. The kinetics of the transients have been modeled to a stretched exponential type function. We believe that nucleation of polar clusters with a reversed polarization occurs under applied field in the vicinity of randomly quenched defects.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"126 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":"124270959","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.2002.1195960
C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze
A modified Bridgman approach, developed at the Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), has been used to grow ferroelectric relaxor PMN-PT single crystals. A series of technological barriers on the growth of ferroelectric relaxor PMN-PT single crystals, such as making seeds, seeded-orientation control, size-enlargement, uniformity of the grown single crystals, and crucible leakage, have been progressively overcome. After poling, the electromechanical properties of the grown PMN-PT single crystals are; weak-field permittivity max (/spl epsiv//sub max/) /spl sim/ 29,000 at 162/spl deg/C, 1 kHz and 1 V/sub rms/, dielectric loss (tan /spl delta/) < 0.9%; piezoelectric coefficient d/sub 33/ > 2,000 pC/N; mechanical-electric coupling factors, k/sub 33/ /spl sim/ 0.92-0.94 and k/sub t/ /spl sim/ 0.61-0.62, respectively. The electromechanical properties of the 67PMN-33PT single crystal composition are measured as a function of temperature. This analysis reveals the effects of the diffuse phase transition on the electromechanical properties as piezoelectricity in the material develops.
{"title":"Characterization study of the growth and electromechanical properties of 67PMN-33PT single crystals","authors":"C. B. DiAntonio, F. Williams, S. Pilgrim, W. Schulze","doi":"10.1109/ISAF.2002.1195960","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195960","url":null,"abstract":"A modified Bridgman approach, developed at the Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), has been used to grow ferroelectric relaxor PMN-PT single crystals. A series of technological barriers on the growth of ferroelectric relaxor PMN-PT single crystals, such as making seeds, seeded-orientation control, size-enlargement, uniformity of the grown single crystals, and crucible leakage, have been progressively overcome. After poling, the electromechanical properties of the grown PMN-PT single crystals are; weak-field permittivity max (/spl epsiv//sub max/) /spl sim/ 29,000 at 162/spl deg/C, 1 kHz and 1 V/sub rms/, dielectric loss (tan /spl delta/) < 0.9%; piezoelectric coefficient d/sub 33/ > 2,000 pC/N; mechanical-electric coupling factors, k/sub 33/ /spl sim/ 0.92-0.94 and k/sub t/ /spl sim/ 0.61-0.62, respectively. The electromechanical properties of the 67PMN-33PT single crystal composition are measured as a function of temperature. This analysis reveals the effects of the diffuse phase transition on the electromechanical properties as piezoelectricity in the material develops.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"57 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":"114854516","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.2002.1195915
D. Mccauley, M. Chu, M. Megherhi, M. Creedon, K. Albertsen, E. Davis
Within the worldwide capacitor industry there is a wide range of synthesis techniques for producing the starting BaTiO/sub 3/ precursor, which is the primary component for X7R capacitor formulations. The intention of this study was to draw some inherent conclusions about advantages or disadvantages of certain synthesis techniques. Several dielectric compositions for high capacitance BME multilayer ceramic capacitor (MLCC) applications have been examined. These formulations are based on BaTiO/sub 3/ precursors that were synthesized from solid state as well as two oxalate methods. The focus of this work was to identify the influence that the host BaTiO/sub 3/ had on the reliability of the MLCC. The model proposed by Prokopowitz and Vaskas was used to characterize the reliability behavior. Analysis of the data shows that it is very difficult to predict how a particular BaTiO/sub 3/ precursor will work in a given BME formulation without actually producing the formulation and performing the appropriate testing. For the solid state based formulation the value obtained for /spl eta/ was much higher than expected where the E/sub a/ was comparable to the values found in the literature. However, while the two oxalate based formulations behaved very differently from the solid state system, they behaved very similar to one another. For these systems, the /spl eta/ was in agreement with the values found in the literature but the E/sub a/ was much higher than expected.
{"title":"BaTiO/sub 3/ synthesis technique and its effect on BME dielectric formulations","authors":"D. Mccauley, M. Chu, M. Megherhi, M. Creedon, K. Albertsen, E. Davis","doi":"10.1109/ISAF.2002.1195915","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195915","url":null,"abstract":"Within the worldwide capacitor industry there is a wide range of synthesis techniques for producing the starting BaTiO/sub 3/ precursor, which is the primary component for X7R capacitor formulations. The intention of this study was to draw some inherent conclusions about advantages or disadvantages of certain synthesis techniques. Several dielectric compositions for high capacitance BME multilayer ceramic capacitor (MLCC) applications have been examined. These formulations are based on BaTiO/sub 3/ precursors that were synthesized from solid state as well as two oxalate methods. The focus of this work was to identify the influence that the host BaTiO/sub 3/ had on the reliability of the MLCC. The model proposed by Prokopowitz and Vaskas was used to characterize the reliability behavior. Analysis of the data shows that it is very difficult to predict how a particular BaTiO/sub 3/ precursor will work in a given BME formulation without actually producing the formulation and performing the appropriate testing. For the solid state based formulation the value obtained for /spl eta/ was much higher than expected where the E/sub a/ was comparable to the values found in the literature. However, while the two oxalate based formulations behaved very differently from the solid state system, they behaved very similar to one another. For these systems, the /spl eta/ was in agreement with the values found in the literature but the E/sub a/ was much higher than expected.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"56 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":"124351566","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.2002.1195935
D. Jin, Z. Meng
We fabricated a PZT/ZnO piezoelectric ceramic actuator with graded distribution of piezoelectric coefficient and resistivity through the thickness. There were tremendous differences of electric properties between its two sides, but these properties changed gradually in the transition region. The PZT composition was determined from authors' previous work. ZnO ceramics was tailored by adding dopants, such as Al and Mn ions, respectively. The microstructure of the sample profile and composition distribution through the thickness was examined by electron probe microanalysis, verifying the existence of gradient microstructure developed from the diffusion of Zn/sup 2+/. The resistivity of ZnO layer is more than ten magnitudes lower than that of PZT layer. This made the PZT layer be more effectively poled and suffered nearly all the driving voltage. Displacement curves of the PZT/ZnO Functionaly Gradient Piezoceramic Actuator (FGMPA) were investigated. The results show that tip displacement of the actuator is higher than that of La-PZT/Fe-PZT FGMPA for the same geometrical dimensions and applied voltage.
{"title":"Fabrication and characterization of piezoelectric ceramic actuators with functional gradients","authors":"D. Jin, Z. Meng","doi":"10.1109/ISAF.2002.1195935","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195935","url":null,"abstract":"We fabricated a PZT/ZnO piezoelectric ceramic actuator with graded distribution of piezoelectric coefficient and resistivity through the thickness. There were tremendous differences of electric properties between its two sides, but these properties changed gradually in the transition region. The PZT composition was determined from authors' previous work. ZnO ceramics was tailored by adding dopants, such as Al and Mn ions, respectively. The microstructure of the sample profile and composition distribution through the thickness was examined by electron probe microanalysis, verifying the existence of gradient microstructure developed from the diffusion of Zn/sup 2+/. The resistivity of ZnO layer is more than ten magnitudes lower than that of PZT layer. This made the PZT layer be more effectively poled and suffered nearly all the driving voltage. Displacement curves of the PZT/ZnO Functionaly Gradient Piezoceramic Actuator (FGMPA) were investigated. The results show that tip displacement of the actuator is higher than that of La-PZT/Fe-PZT FGMPA for the same geometrical dimensions and applied voltage.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"9 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":"122083067","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.2002.1195874
H. Ohsato, A. Kan, K. Kakimoto, H. Ogawa, S. Nishigaki
Microwave dielectric properties, quality factor, dielectric constant and temperature coefficient of resonant frequency, are discussed based on the crystal structure analysis of two systems. The tungstenbronze-type like Ba/sub 6-3x/R/sub 8+2x/Ti/sub 18/O/sub 54/ (R = rare earth) solid solutions and Y/sub 2/BaCuO/sub 5/ green phase are addressed as examples. The quality factor (Q/spl middot/f) is improved by ordering due to phase transformation, compositional ordering of cations and purifying the composition. Dielectric constant (/spl epsiv//sub r/) is affected by volume of cation polyhedron, tilting of TiO/sub 6/ octahedron and polarizability of cations. Temperature coefficients of resonant frequency is studied by crystal structural analysis with different temperature.
{"title":"Microwave dielectric properties correlated to crystal structure: an analysis","authors":"H. Ohsato, A. Kan, K. Kakimoto, H. Ogawa, S. Nishigaki","doi":"10.1109/ISAF.2002.1195874","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195874","url":null,"abstract":"Microwave dielectric properties, quality factor, dielectric constant and temperature coefficient of resonant frequency, are discussed based on the crystal structure analysis of two systems. The tungstenbronze-type like Ba/sub 6-3x/R/sub 8+2x/Ti/sub 18/O/sub 54/ (R = rare earth) solid solutions and Y/sub 2/BaCuO/sub 5/ green phase are addressed as examples. The quality factor (Q/spl middot/f) is improved by ordering due to phase transformation, compositional ordering of cations and purifying the composition. Dielectric constant (/spl epsiv//sub r/) is affected by volume of cation polyhedron, tilting of TiO/sub 6/ octahedron and polarizability of cations. Temperature coefficients of resonant frequency is studied by crystal structural analysis with different temperature.","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":"129904234","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.2002.1195955
M. Adachi, T. Funakawa, T. Karaki
It has been attempted to grow new langasite crystals. Ba/sub 3/Nb/sub 2/Ga/sub 4/O/sub 14/, Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ and Ba/sub 3/Nb/sub 0.5/Ga/sub 2.5/Si/sub 3/O/sub 14/ have been synthesized by solid state reaction and then grown by the Czochralski method. Among them, only Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ is a langasite structure and its melting temperature is 1260/spl deg/C. Growth of this crystal has been attempted, but a single phase Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ could not be grown because Ba ion is too large for A site in this system. Further, by substitution of Ba with Ca in Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/, transparent and colorless Ca/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ crystals have been successfully grown at the melting point of 1325/spl deg/C.
{"title":"Growth of substituted langasite-type Ca/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ single crystals, and their dielectric, elastic and piezoelectric properties","authors":"M. Adachi, T. Funakawa, T. Karaki","doi":"10.1109/ISAF.2002.1195955","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195955","url":null,"abstract":"It has been attempted to grow new langasite crystals. Ba/sub 3/Nb/sub 2/Ga/sub 4/O/sub 14/, Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ and Ba/sub 3/Nb/sub 0.5/Ga/sub 2.5/Si/sub 3/O/sub 14/ have been synthesized by solid state reaction and then grown by the Czochralski method. Among them, only Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ is a langasite structure and its melting temperature is 1260/spl deg/C. Growth of this crystal has been attempted, but a single phase Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ could not be grown because Ba ion is too large for A site in this system. Further, by substitution of Ba with Ca in Ba/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/, transparent and colorless Ca/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ crystals have been successfully grown at the melting point of 1325/spl deg/C.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"11 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120894265","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.2002.1195891
H. Fukuda, K. Kimura, K. Salam, S. Nomura
Polycrystalline PbTiO/sub 3/ thin films were successfully formed on SrTiO/sub 3/ buffer layer by metalorganic decomposition (MOD) technique. The PbTiO/sub 3/ films showed the perovskite structure after annealing at 700/spl deg/C for 30 min in N/sub 2/ ambient. A higher dielectric constant of 157 is obtained in the PbTiO/sub 3//SrTiO/sub 3//Si structure. The hysteresis loop in the capacitance-voltage curves of the MFIS configuration indicated a memory window of 1.2 V with a programming voltage swing of /spl plusmn/5 V due to polarization effect. The memory window will satisfy the practical application of the MFIS-FET memories operating at low voltage in future ULSIs.
{"title":"Structure control of ferroelectric PbTiO/sub 3/ thin films using SrTiO/sub 3/ buffer layer prepared by metalorganic decomposition","authors":"H. Fukuda, K. Kimura, K. Salam, S. Nomura","doi":"10.1109/ISAF.2002.1195891","DOIUrl":"https://doi.org/10.1109/ISAF.2002.1195891","url":null,"abstract":"Polycrystalline PbTiO/sub 3/ thin films were successfully formed on SrTiO/sub 3/ buffer layer by metalorganic decomposition (MOD) technique. The PbTiO/sub 3/ films showed the perovskite structure after annealing at 700/spl deg/C for 30 min in N/sub 2/ ambient. A higher dielectric constant of 157 is obtained in the PbTiO/sub 3//SrTiO/sub 3//Si structure. The hysteresis loop in the capacitance-voltage curves of the MFIS configuration indicated a memory window of 1.2 V with a programming voltage swing of /spl plusmn/5 V due to polarization effect. The memory window will satisfy the practical application of the MFIS-FET memories operating at low voltage in future ULSIs.","PeriodicalId":415725,"journal":{"name":"Proceedings of the 13th IEEE International Symposium on Applications of Ferroelectrics, 2002. ISAF 2002.","volume":"546 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":"116712165","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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