Pub Date : 2018-09-11DOI: 10.1109/ISAF.2018.8463221
Yukio Watanabe, D. Matsumoto, Y. Urakami, M. Okano, A. Masuda
The conductions at domain boundaries due to ferroelectric polarization and LaAlO3/SrTiO3found by Ohtomo and Hwang [Nature 427, 423 (2004)] are intriguing. If these conductions are different from the conventional conductions at domain boundaries and oxide interfaces due to defects, they prove the earlier predictions [Phys. Rev. Lett. 86, 332(2001); Phys. Rev. B57, 789(1998)]. That is, when these conductions are primarily due to ferroelectric polarization as predicted, the foundations of mesoscale and nanoscale ferroelectrics should change. Considering conventional mechanisms including the high field effect as in the resistance switching (RRAM), we examine their origin and discuss these implications.
Ohtomo和Hwang发现的由铁电极化和LaAlO3/ srtio3引起的畴边界电导非常有趣[Nature 427, 423(2004)]。如果这些电导由于缺陷而与畴边界和氧化物界面的常规电导不同，它们就证明了早期的预测[物理学家]。Rev. Lett. 86, 332(2001);理论物理。Rev. B57, 789(1998)]。也就是说，当这些导电主要是由铁电极化引起时，中尺度和纳米尺度铁电体的基础应该改变。考虑到传统的机制，包括电阻开关(RRAM)中的高场效应，我们研究了它们的起源并讨论了这些影响。
{"title":"Origins of Conduction at Domain Boundaries, LaAlO3/SrTiO3 and Surface for Depolarization & Size Effect","authors":"Yukio Watanabe, D. Matsumoto, Y. Urakami, M. Okano, A. Masuda","doi":"10.1109/ISAF.2018.8463221","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463221","url":null,"abstract":"The conductions at domain boundaries due to ferroelectric polarization and LaAlO3/SrTiO3found by Ohtomo and Hwang [Nature 427, 423 (2004)] are intriguing. If these conductions are different from the conventional conductions at domain boundaries and oxide interfaces due to defects, they prove the earlier predictions [Phys. Rev. Lett. 86, 332(2001); Phys. Rev. B57, 789(1998)]. That is, when these conductions are primarily due to ferroelectric polarization as predicted, the foundations of mesoscale and nanoscale ferroelectrics should change. Considering conventional mechanisms including the high field effect as in the resistance switching (RRAM), we examine their origin and discuss these implications.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132131759","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 : 2018-07-10DOI: 10.1109/ISAF.2018.8463311
M. Kawano, T. Yamada, S. Matsuo, M. Yoshino, T. Nagasaki, O. Sakata, Y. Imai
(K1-xNax)NbO3 (KNN) is especially paid attention to as a lead-free piezoelectric material. It is known that KNN has a morphotropic phase boundary (MPB) at $xsim 0.5$, which shows a high piezoelectric property. However, it has not been fully clarified how the domain structure of KNN changes by applied electric field. In this study, we observed electric field-induced strain and domain fraction change of KNN films by synchrotron X-ray diffraction.
{"title":"Domain Switching by Applied Electric Field in (001) and (111)-epitaxial (K0.5Na0.5)NbO3Films","authors":"M. Kawano, T. Yamada, S. Matsuo, M. Yoshino, T. Nagasaki, O. Sakata, Y. Imai","doi":"10.1109/ISAF.2018.8463311","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463311","url":null,"abstract":"(K1-xNax)NbO3 (KNN) is especially paid attention to as a lead-free piezoelectric material. It is known that KNN has a morphotropic phase boundary (MPB) at $xsim 0.5$, which shows a high piezoelectric property. However, it has not been fully clarified how the domain structure of KNN changes by applied electric field. In this study, we observed electric field-induced strain and domain fraction change of KNN films by synchrotron X-ray diffraction.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123029413","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463245
Jian Yu, Jun Yu Li, Yinglong Jiang, J. Chu
Materials Genome Initiative is envisioning the discovery, development, manufacturing and deployment of advanced materials twice as fast and at a fraction of cost. High throughput computation and experimentation will generate big data, which underscores the emergence of the fourth paradigm data science. In contrast to machine-learning needing big-data, data-mining assisted by domain knowledge and expertise works well with a limited number of data. In this presentation, data-mining based on material genome approach were performed in field of perovskite-type oxides. New ferroelectric ceramics based on BiFeO3 for high temperature piezoelectric applications are realized with piezoresponse of 1.5~4.0 times the present commercial non-perovskite counterpart. Our essay demonstrates data-mining driven searching sure able to reduce time-to-insight and human effort on synthesization, accelerating new materials discovery and deployment.
{"title":"Data-Mining Driven Design for Novel Perovskite-type Piezoceramics","authors":"Jian Yu, Jun Yu Li, Yinglong Jiang, J. Chu","doi":"10.1109/ISAF.2018.8463245","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463245","url":null,"abstract":"Materials Genome Initiative is envisioning the discovery, development, manufacturing and deployment of advanced materials twice as fast and at a fraction of cost. High throughput computation and experimentation will generate big data, which underscores the emergence of the fourth paradigm data science. In contrast to machine-learning needing big-data, data-mining assisted by domain knowledge and expertise works well with a limited number of data. In this presentation, data-mining based on material genome approach were performed in field of perovskite-type oxides. New ferroelectric ceramics based on BiFeO3 for high temperature piezoelectric applications are realized with piezoresponse of 1.5~4.0 times the present commercial non-perovskite counterpart. Our essay demonstrates data-mining driven searching sure able to reduce time-to-insight and human effort on synthesization, accelerating new materials discovery and deployment.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115570244","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463232
S. Maejima, M. Uchida, M. Noda
We found a new phenomenon that shows a large change in leakage current through BaTiO3(BTO) film with the maximum ratio of 107 to 109 observed in this work by changing cumulative cycle of voltage scan applied on the film capacitor. These leakage phenomena are thought to depend on several factors such as BTO film thickness, concentration of $V_{0}^{+}$, bias voltage, its sweep rate and so on, because trapping/detrapping of carrier electron into/from oxygen vacancy would be a competition dependent on their rates and concentrations. These results imply that the leakage current can be controlled by some sequences or protocols of applied voltage scan, leading to use for ReRAM or neuromorphic applications.
{"title":"Control of Leakage Current through BaTiO3 Film by Cumulative Cycle of Applied Voltage Scanning for ReRAM or Neuromorphic Application","authors":"S. Maejima, M. Uchida, M. Noda","doi":"10.1109/ISAF.2018.8463232","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463232","url":null,"abstract":"We found a new phenomenon that shows a large change in leakage current through BaTiO3(BTO) film with the maximum ratio of 107 to 109 observed in this work by changing cumulative cycle of voltage scan applied on the film capacitor. These leakage phenomena are thought to depend on several factors such as BTO film thickness, concentration of $V_{0}^{+}$, bias voltage, its sweep rate and so on, because trapping/detrapping of carrier electron into/from oxygen vacancy would be a competition dependent on their rates and concentrations. These results imply that the leakage current can be controlled by some sequences or protocols of applied voltage scan, leading to use for ReRAM or neuromorphic applications.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131918508","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463278
K. Yamashita, Shōta Nakajima, Jo Shiomi, M. Noda, P. Muralt
Piezoelectric ultrasonic microsensors with a PZT (lead-zirconate-titanate) capacitor on a buckled diaphragm were fabricated and deposition condition of the sol-gel derived PZT films was investigated from the viewpoint of high mechano-electrical conversion efficiency. The buckling of the diaphragm affects the conversion efficiency in the geometrical aspect and is influenced by the residual stress of the diaphragm. The films were deposited through various thermal treatment in the sol-gel process; four pyrolysis temperatures and two first-crystallized gel film thickness, and were evaluated in their stress and ferroelectric property. The thickness of the gel film affected the crystallographic orientation, (100) or (111), of the film, and dominated the film stress and remanent polarization, e.g., the stress and polarization of the (100)-oriented films were smaller than those of the (lll)-oriented films, meaning the (100) orientation is better in the stress but worse in the remanent polarization than (111) orientation. The pyrolysis temperature was then precisely controlled and finally orientation-distributed samples were fabricated and evaluated. The samples with mixed orientation of (100) and (111) in around 50% showed intermediate stress and remanent polarization, and their sensitivity was enhanced by 1.4-4 times to those with (100) or (111) single oriented films.
{"title":"Piezoelectric Ultrasonic Microsensors on Buckled Diaphragms Using Sol-Gel Derived PZT Films","authors":"K. Yamashita, Shōta Nakajima, Jo Shiomi, M. Noda, P. Muralt","doi":"10.1109/ISAF.2018.8463278","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463278","url":null,"abstract":"Piezoelectric ultrasonic microsensors with a PZT (lead-zirconate-titanate) capacitor on a buckled diaphragm were fabricated and deposition condition of the sol-gel derived PZT films was investigated from the viewpoint of high mechano-electrical conversion efficiency. The buckling of the diaphragm affects the conversion efficiency in the geometrical aspect and is influenced by the residual stress of the diaphragm. The films were deposited through various thermal treatment in the sol-gel process; four pyrolysis temperatures and two first-crystallized gel film thickness, and were evaluated in their stress and ferroelectric property. The thickness of the gel film affected the crystallographic orientation, (100) or (111), of the film, and dominated the film stress and remanent polarization, e.g., the stress and polarization of the (100)-oriented films were smaller than those of the (lll)-oriented films, meaning the (100) orientation is better in the stress but worse in the remanent polarization than (111) orientation. The pyrolysis temperature was then precisely controlled and finally orientation-distributed samples were fabricated and evaluated. The samples with mixed orientation of (100) and (111) in around 50% showed intermediate stress and remanent polarization, and their sensitivity was enhanced by 1.4-4 times to those with (100) or (111) single oriented films.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134193787","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463226
Tai-Ho Yu
A bi-dimensional finite element model based on Hamilton's principle and the finite element method is developed in this study to analyze the dispersive characteristics and mode shapes of normal modes for circular wedge acoustic waveguides. The dispersion curves of phase velocities for guided waves and their corresponding resonant frequencies for a circular wedge waveguide were also evaluated by 3D finite element analysis (FEA) using the commercial ANSYS code. The convergence of guided waves was discussed. The 3D FEA was limited in terms of calculating for higher normal modes due to constraints in the available number of elements. The bi-dimensional finite element method is based on the separation of variables, with the wave propagation factor being separated from cross-sectional vibrations of the acoustic waveguides. The present method has advantages in terms of being able to determine phase velocities and mode shapes up to higher normal modes and in a wide range of frequencies without loss of accuracy. The phase velocities of the anti-symmetric flexural (ASF) guided waves in circular wedge waveguides were found to be slower than the Rayleigh wave speed. Furthermore, the calculated results in the range of higher wave numbers were in good agreement with the empirical formula provided by Lagasse [1]. The ASF waves in circular cylindrical wedge-typed waveguides were found to have faster and frequency-dependent phase velocities in the range of lower wave numbers. This phenomenon results from the boundary conditions on the bottom of waveguides, which are different from the ideal wedge problem considered in Lagasse's work. In addition, the curvatures of the acoustic waveguides were found to increase the phase velocities of higher normal modes only.
{"title":"Vibration Mode Analyses for Circular Wedge Acoustic Waveguides","authors":"Tai-Ho Yu","doi":"10.1109/ISAF.2018.8463226","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463226","url":null,"abstract":"A bi-dimensional finite element model based on Hamilton's principle and the finite element method is developed in this study to analyze the dispersive characteristics and mode shapes of normal modes for circular wedge acoustic waveguides. The dispersion curves of phase velocities for guided waves and their corresponding resonant frequencies for a circular wedge waveguide were also evaluated by 3D finite element analysis (FEA) using the commercial ANSYS code. The convergence of guided waves was discussed. The 3D FEA was limited in terms of calculating for higher normal modes due to constraints in the available number of elements. The bi-dimensional finite element method is based on the separation of variables, with the wave propagation factor being separated from cross-sectional vibrations of the acoustic waveguides. The present method has advantages in terms of being able to determine phase velocities and mode shapes up to higher normal modes and in a wide range of frequencies without loss of accuracy. The phase velocities of the anti-symmetric flexural (ASF) guided waves in circular wedge waveguides were found to be slower than the Rayleigh wave speed. Furthermore, the calculated results in the range of higher wave numbers were in good agreement with the empirical formula provided by Lagasse [1]. The ASF waves in circular cylindrical wedge-typed waveguides were found to have faster and frequency-dependent phase velocities in the range of lower wave numbers. This phenomenon results from the boundary conditions on the bottom of waveguides, which are different from the ideal wedge problem considered in Lagasse's work. In addition, the curvatures of the acoustic waveguides were found to increase the phase velocities of higher normal modes only.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114937581","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463273
K. Yamashita, P. Muralt
A resonating force sensor is studied, which is composed of a metal bridge coated with a piezoelectric film for force detection. It is thought to operate the sensor at the second flexural vibration mode having one node at the center of the bridge. Resonance frequency and piezoelectric coupling are investigated in the frame of an analytical model, and compared with finite element analysis (FEA) in a desired force range. The resonance frequency-force relation derived from the analytical model is close the the FEA result in the force range. The coupling factor-force relation from the analytical model agrees with the one from FEA in the small force region, but it shows lower coupling than the FEA result in the large force region.
{"title":"Piezoelectric Resonating Force Sensor in the Second Vibration Mode","authors":"K. Yamashita, P. Muralt","doi":"10.1109/ISAF.2018.8463273","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463273","url":null,"abstract":"A resonating force sensor is studied, which is composed of a metal bridge coated with a piezoelectric film for force detection. It is thought to operate the sensor at the second flexural vibration mode having one node at the center of the bridge. Resonance frequency and piezoelectric coupling are investigated in the frame of an analytical model, and compared with finite element analysis (FEA) in a desired force range. The resonance frequency-force relation derived from the analytical model is close the the FEA result in the force range. The coupling factor-force relation from the analytical model agrees with the one from FEA in the small force region, but it shows lower coupling than the FEA result in the large force region.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131265110","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463253
W. Xia, Yalin Yin, Junhong Xing, Ning Zhang, Zhuo Xu
A core-shell inorganic/polymer materials with abundant compositions and multiple shapes have attracted many attentions recently for their harmonious interfacial compatibility, high dielectric performance, and thereby the prospect of applications in energy storage devices. In this work, for improving the interfacial compatibility of in organiclpolymer nanocomposites, the BaTiO3 (BT) nano-powders are coated successively by using double shell polyamide (HBP) and dopamine (PDA) that is decorated with nanoscale Ag particles. In addition, a P(VDF-CTFE) with high breakdown electric field and proper dielectric permittivity are selected as the polymer matrix, and the flexible 0–3 nanocomposite of Ag decorated P(VDF-CTFE)/BT@HBP@PDA films with ~20μm in thickness are obtained through spin-casting method. The morphologies from FESEM show that the interface between BaTiO3 and P(VDF-CTFE) has been improved significantly and BaTiO3 is homogeneous dispersion in the polymer matrix. Consequently, the multicomponent nanocomposites possess the large dielectric permittivity (εr~40) and a low dielectric loss tangent (0.1 Hz) since the ionic polarization of BaTiO3 and the penetration effect of electrons. The result provides an effective way of interfacial improving that through various mutual promoting mediums to achieve high dielectric performance composite materials for their potential applications in energy storage areas.
{"title":"An Ag Decorated P(VDF-CTFE)/BT@HBP@PDA Nanocomposites with Double-Shell Core Structure for High Dielectric Performance","authors":"W. Xia, Yalin Yin, Junhong Xing, Ning Zhang, Zhuo Xu","doi":"10.1109/ISAF.2018.8463253","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463253","url":null,"abstract":"A core-shell inorganic/polymer materials with abundant compositions and multiple shapes have attracted many attentions recently for their harmonious interfacial compatibility, high dielectric performance, and thereby the prospect of applications in energy storage devices. In this work, for improving the interfacial compatibility of in organiclpolymer nanocomposites, the BaTiO3 (BT) nano-powders are coated successively by using double shell polyamide (HBP) and dopamine (PDA) that is decorated with nanoscale Ag particles. In addition, a P(VDF-CTFE) with high breakdown electric field and proper dielectric permittivity are selected as the polymer matrix, and the flexible 0–3 nanocomposite of Ag decorated P(VDF-CTFE)/BT@HBP@PDA films with ~20μm in thickness are obtained through spin-casting method. The morphologies from FESEM show that the interface between BaTiO3 and P(VDF-CTFE) has been improved significantly and BaTiO3 is homogeneous dispersion in the polymer matrix. Consequently, the multicomponent nanocomposites possess the large dielectric permittivity (εr~40) and a low dielectric loss tangent (0.1 Hz) since the ionic polarization of BaTiO3 and the penetration effect of electrons. The result provides an effective way of interfacial improving that through various mutual promoting mediums to achieve high dielectric performance composite materials for their potential applications in energy storage areas.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126519290","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463349
N. A. Emelianov, L. Korotkov, W. M. Al Mandalawi, M. Kashirin, J. Roldan López, T. N. Korotkova
Dependences of magnetization on magnetic field strength were studied for both the nanostructured and the bulk ferroelectric barium titanate. It has been found that nanostructured barium titanate demonstrates ferroelectric, ferromagnetic and diamagnetic properties simultaneously. The annealing of nanostructured barium titanate in hydrogen atmosphere under experimental conditions leads to a significant increase of the spontaneous magnetization and decrease of the diamagnetic response. Analysis of experimental results shows that defects in grains surfaces of the barium titanate nanoparticles (probably oxygen vacancies) are mainly responsible for electron states, which produce ferromagnetic and diamagnetic responses.
{"title":"Ferromagnetism in barium titanate nanoparticles. Effect of annealing in hydrogen atmosphere on magnetic properties","authors":"N. A. Emelianov, L. Korotkov, W. M. Al Mandalawi, M. Kashirin, J. Roldan López, T. N. Korotkova","doi":"10.1109/ISAF.2018.8463349","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463349","url":null,"abstract":"Dependences of magnetization on magnetic field strength were studied for both the nanostructured and the bulk ferroelectric barium titanate. It has been found that nanostructured barium titanate demonstrates ferroelectric, ferromagnetic and diamagnetic properties simultaneously. The annealing of nanostructured barium titanate in hydrogen atmosphere under experimental conditions leads to a significant increase of the spontaneous magnetization and decrease of the diamagnetic response. Analysis of experimental results shows that defects in grains surfaces of the barium titanate nanoparticles (probably oxygen vacancies) are mainly responsible for electron states, which produce ferromagnetic and diamagnetic responses.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130785020","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 : 2018-05-01DOI: 10.1109/ISAF.2018.8463243
R. Dahl-Hansen, T. Tybell, F. Tyholdt
The number of application areas for piezoelectric micro electromechanical systems based on PZT have increased rapidly over the years. Thus, to continue the development towards commercial deployment, characterizing lifetime and reliability during operation in realistic and harsh environments is important. Such environments are demanding for piezoMEMS devices since they often involve high humidity levels and elevated temperatures which gives rise to complex degradation. To address how such conditions affects device performance we combined optical and electrical measurements to elucidate the degradation of a PZT-based thin-film piezoelectric MEMS micromirror during temperature-humidity-cycling tests. As a test structure, $1 mu m PbZr_{0.40}Ti_{0.60}O_{3}$ on a 10 nm LaNiO3 buffer-layer, were deposited by pulsed laser deposition on platinized Silicon-on-Insulator wafers. A 250 nm Au/TiW top electrode was deposited by DC-sputtering before structuring the final device. The micro mirrors were unipolarly actuated with a signal of $20 V$ peak-to-peak at a frequency of 1.5 kHz in an ambient with constant vapor concentration of 22 $g/m^{3}$ for device temperatures between 25${}^{o}C$ and 175${}^{o}C$. Humidity-related degradation was manifested as local breakdown events and pinholes on top of and along the edges of the used electrodes. This had a strong effect on device performance and preceded degradation due to polarization-fatigue at all temperatures. Also, both the initial piezoelectric response and number of cycles to device failure increased with increasing substrate temperature in humid ambient.
{"title":"Performance and reliability of PZT-based piezoelectric micromirrors operated in realistic environments","authors":"R. Dahl-Hansen, T. Tybell, F. Tyholdt","doi":"10.1109/ISAF.2018.8463243","DOIUrl":"https://doi.org/10.1109/ISAF.2018.8463243","url":null,"abstract":"The number of application areas for piezoelectric micro electromechanical systems based on PZT have increased rapidly over the years. Thus, to continue the development towards commercial deployment, characterizing lifetime and reliability during operation in realistic and harsh environments is important. Such environments are demanding for piezoMEMS devices since they often involve high humidity levels and elevated temperatures which gives rise to complex degradation. To address how such conditions affects device performance we combined optical and electrical measurements to elucidate the degradation of a PZT-based thin-film piezoelectric MEMS micromirror during temperature-humidity-cycling tests. As a test structure, $1 mu m PbZr_{0.40}Ti_{0.60}O_{3}$ on a 10 nm LaNiO3 buffer-layer, were deposited by pulsed laser deposition on platinized Silicon-on-Insulator wafers. A 250 nm Au/TiW top electrode was deposited by DC-sputtering before structuring the final device. The micro mirrors were unipolarly actuated with a signal of $20 V$ peak-to-peak at a frequency of 1.5 kHz in an ambient with constant vapor concentration of 22 $g/m^{3}$ for device temperatures between 25${}^{o}C$ and 175${}^{o}C$. Humidity-related degradation was manifested as local breakdown events and pinholes on top of and along the edges of the used electrodes. This had a strong effect on device performance and preceded degradation due to polarization-fatigue at all temperatures. Also, both the initial piezoelectric response and number of cycles to device failure increased with increasing substrate temperature in humid ambient.","PeriodicalId":231071,"journal":{"name":"2018 IEEE ISAF-FMA-AMF-AMEC-PFM Joint Conference (IFAAP)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127174814","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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