Pub Date : 2008-12-02DOI: 10.1109/ISAF.2008.4693849
S. Hoffmann‐Eifert, Takayuki Watanabe, C. Hwang, R. Waser
Quaternary Pb(Zr,Ti)Ox [PZT] films were deposited at 240°C by a combination of liquid injection atomic layer depositions (ALD) of binary PbO, TiOx, and ZrOx thin films. To find the optimum set of precursors different combinations of five precursors were tested: Pb(C11H19O2)2 [Pb(DPM)2], Ti(OC3H7)2(C11H19O2)2 [Ti(Oi-Pr)2(DPM)2] or Ti(OC3H7)4 [Ti(Oi-Pr)4], and Zr(C11H19O2)4 [Zr(DPM)4] or Zr(C9H15O2)4 [Zr(DIBM)4]. Each precursor was dissolved in ethylcyclohexane (ECH) and was separately injected into a vaporizer. Water vapor was used as oxidant. The deposition rates of the metal elements were investigated as a function of the input of the solutions. Using the set of 0.1M Pb(DPM)2, Ti(Oi-Pr)4, and Zr(DIBM)4 solutions resulted in PZT films with good uniformity on 3D structured substrates. The Zr to Ti ratio in the as-deposited PZT films could be adjusted in the range up to Zr/Ti =1. This study suggests that the multi-layer stacking liquid delivery ALD process is an effective method for building up homogeneous layers of multi-component materials on desired 3D structures.
{"title":"Liquid injection atomic layer deposition of perovskite-type multi-component oxide thin films for ferroelectric and higher-k three dimensional capacitor structures","authors":"S. Hoffmann‐Eifert, Takayuki Watanabe, C. Hwang, R. Waser","doi":"10.1109/ISAF.2008.4693849","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693849","url":null,"abstract":"Quaternary Pb(Zr,Ti)Ox [PZT] films were deposited at 240°C by a combination of liquid injection atomic layer depositions (ALD) of binary PbO, TiOx, and ZrOx thin films. To find the optimum set of precursors different combinations of five precursors were tested: Pb(C11H19O2)2 [Pb(DPM)2], Ti(OC3H7)2(C11H19O2)2 [Ti(Oi-Pr)2(DPM)2] or Ti(OC3H7)4 [Ti(Oi-Pr)4], and Zr(C11H19O2)4 [Zr(DPM)4] or Zr(C9H15O2)4 [Zr(DIBM)4]. Each precursor was dissolved in ethylcyclohexane (ECH) and was separately injected into a vaporizer. Water vapor was used as oxidant. The deposition rates of the metal elements were investigated as a function of the input of the solutions. Using the set of 0.1M Pb(DPM)2, Ti(Oi-Pr)4, and Zr(DIBM)4 solutions resulted in PZT films with good uniformity on 3D structured substrates. The Zr to Ti ratio in the as-deposited PZT films could be adjusted in the range up to Zr/Ti =1. This study suggests that the multi-layer stacking liquid delivery ALD process is an effective method for building up homogeneous layers of multi-component materials on desired 3D structures.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114357334","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693826
J. Sun, E. K. Akdoğan, M. Vittadello, A. Safari
The Micropen¿ direct-write technique was used to fabricate ceramic skeletal structures to develop ceramic/polymer (2-2) composites for high frequency transducers in medical imaging applications. Both regular and volume fraction gradient (VFG) patterns were designed. By this approach, transducers were fabricated with 1 cm2 transduction area, operating at 4¿5 MHz. The composites had ~30 vol% of ceramic, with thickness ranging 290 to 380 ¿m. They had a dielectric loss of 2.0¿2.1%, a dielectric constant of 500¿670, a d33 of 190, and kt of 56%¿61%.
{"title":"Development of novel (2-2) piezoelectric composites by direct-write technique","authors":"J. Sun, E. K. Akdoğan, M. Vittadello, A. Safari","doi":"10.1109/ISAF.2008.4693826","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693826","url":null,"abstract":"The Micropen¿ direct-write technique was used to fabricate ceramic skeletal structures to develop ceramic/polymer (2-2) composites for high frequency transducers in medical imaging applications. Both regular and volume fraction gradient (VFG) patterns were designed. By this approach, transducers were fabricated with 1 cm2 transduction area, operating at 4¿5 MHz. The composites had ~30 vol% of ceramic, with thickness ranging 290 to 380 ¿m. They had a dielectric loss of 2.0¿2.1%, a dielectric constant of 500¿670, a d33 of 190, and kt of 56%¿61%.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116500910","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693742
Y. Sakai, T. Futakuchi, M. Adachi
0.995(Ba0.6Sr0.4)TiO3-0.005MgTiO3 thick films with SiO2 and (Ba0.6Sr0.4)TiO3 thick films have been prepared by the inkjet printing. Dielectric constant and tan¿ of the prepared thick films were measured at 100 kHz. Both dielectric constant and tan¿ were improved by MgTiO3 and SiO2 addition. S21 parameter of thick films was measured to examine the electric properties at high frequency. Resonant frequency of S21 parameter was increased by applying DC electric field. These results indicate the application of the thick films prepared by inkjet printing to tunable filters at high frequency.
{"title":"Investigation of (Ba,Sr)TiO3 based thick films prepared by inkjet printing","authors":"Y. Sakai, T. Futakuchi, M. Adachi","doi":"10.1109/ISAF.2008.4693742","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693742","url":null,"abstract":"0.995(Ba0.6Sr0.4)TiO3-0.005MgTiO3 thick films with SiO2 and (Ba0.6Sr0.4)TiO3 thick films have been prepared by the inkjet printing. Dielectric constant and tan¿ of the prepared thick films were measured at 100 kHz. Both dielectric constant and tan¿ were improved by MgTiO3 and SiO2 addition. S21 parameter of thick films was measured to examine the electric properties at high frequency. Resonant frequency of S21 parameter was increased by applying DC electric field. These results indicate the application of the thick films prepared by inkjet printing to tunable filters at high frequency.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126366499","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693941
Seok-Jin Yoon, Hyung-chan Kim, Dae-Yong Jeon, Hyun-Jai Kim
Piezoelectric energy harvesting has been attractive for powering the wireless sensor node in Ubiquitous Sensor Networks. The piezoelectric energy harvesting characteristics can be controlled by changing the material properties or material geometry. For example, by changing the material property, the electromechanical coupling coefficient, large electric power can be generated even with the same mechanical energy. Instead of ceramic material, we used the PMN-PT single crystal for the cantilever type energy harvester and characterized the energy harvesting properties of PMN-PT single crystals for different electric boundary conditions. Piezoelectric materials are featured as a small current and high voltage generator. In this presentation, we will show one example to increase the current by making the multi-layer ceramics.
{"title":"Control of piezoelectric energy harvesting characteristics via the materials properties or geometry modification","authors":"Seok-Jin Yoon, Hyung-chan Kim, Dae-Yong Jeon, Hyun-Jai Kim","doi":"10.1109/ISAF.2008.4693941","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693941","url":null,"abstract":"Piezoelectric energy harvesting has been attractive for powering the wireless sensor node in Ubiquitous Sensor Networks. The piezoelectric energy harvesting characteristics can be controlled by changing the material properties or material geometry. For example, by changing the material property, the electromechanical coupling coefficient, large electric power can be generated even with the same mechanical energy. Instead of ceramic material, we used the PMN-PT single crystal for the cantilever type energy harvester and characterized the energy harvesting properties of PMN-PT single crystals for different electric boundary conditions. Piezoelectric materials are featured as a small current and high voltage generator. In this presentation, we will show one example to increase the current by making the multi-layer ceramics.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128031849","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693773
Ho Won Jang, S. Baek, D. Ortiz, C. M. Folkman, R. Das, Y. Chu, J. Zhang, V. Vaithyanathan, S. Choudhury, Y. Chen, X. Pan, D. Schlom, L. Chen, R. Ramesh, C. Eom
We report the strain dependence of remanent polarization and coercive field of epitaxial (001)p BiFeO3 films. Our measurements reveal that the large spontanoues polarization of BiFeO3 is indeed intrinsic, the remanent polarization of (001)p BiFeO3 thin films has a strong strain dependence, even stronger than (001) PbTiO3 films, and the coercive field of BiFeO3 films is also tunable. In addition, the low coercive filed and the reduced leakage current in (001)p BiFeO3 membranes allows us to achieve a fatigue-free switching behavior to 1010 cycles. This experimental result strongly suggests that epitaxial (001)p BiFeO3 thin films are very promising materials for non-volatile memories and magnetoelectric devices.
{"title":"Strain tunability of spontaneous polarization and enhanced ferroelectric properties in epitaxial (001) BiFeO3 thin films","authors":"Ho Won Jang, S. Baek, D. Ortiz, C. M. Folkman, R. Das, Y. Chu, J. Zhang, V. Vaithyanathan, S. Choudhury, Y. Chen, X. Pan, D. Schlom, L. Chen, R. Ramesh, C. Eom","doi":"10.1109/ISAF.2008.4693773","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693773","url":null,"abstract":"We report the strain dependence of remanent polarization and coercive field of epitaxial (001)p BiFeO3 films. Our measurements reveal that the large spontanoues polarization of BiFeO3 is indeed intrinsic, the remanent polarization of (001)p BiFeO3 thin films has a strong strain dependence, even stronger than (001) PbTiO3 films, and the coercive field of BiFeO3 films is also tunable. In addition, the low coercive filed and the reduced leakage current in (001)p BiFeO3 membranes allows us to achieve a fatigue-free switching behavior to 1010 cycles. This experimental result strongly suggests that epitaxial (001)p BiFeO3 thin films are very promising materials for non-volatile memories and magnetoelectric devices.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"300 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121733500","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693763
Soonil Lee, G. Rossetti, Zirui Liu, C. Randall
The defect and phase equilibria of nonstoichiometric BaTiO3 have been systematically investigated. Self-consistent data were obtained and successfully modeled analytically with defect reactions taking into account the dependent variables of Ba/Ti ratio, temperature, and oxygen partial pressure (Po2). The compositional dependence of the ferroelectric properties in the solid solution regime was described by the Landau-Devonshire theory allowing the parameters of the theory to be functions of stoichiometry. With this approach, we are able to self-consistently determine the spontaneous polarization, dielectric constant, and energetics of the paraelectric-ferroelectric phase transition of powder samples. This theoretical approach provided a way of predicting the intrinsic properties of nonstoichiometric BaTiO3, which have had no previous complete determination or consideration.
{"title":"Phenomenological analysis for intrinsic properties of nonstoichiometric BaTiO3","authors":"Soonil Lee, G. Rossetti, Zirui Liu, C. Randall","doi":"10.1109/ISAF.2008.4693763","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693763","url":null,"abstract":"The defect and phase equilibria of nonstoichiometric BaTiO3 have been systematically investigated. Self-consistent data were obtained and successfully modeled analytically with defect reactions taking into account the dependent variables of Ba/Ti ratio, temperature, and oxygen partial pressure (Po2). The compositional dependence of the ferroelectric properties in the solid solution regime was described by the Landau-Devonshire theory allowing the parameters of the theory to be functions of stoichiometry. With this approach, we are able to self-consistently determine the spontaneous polarization, dielectric constant, and energetics of the paraelectric-ferroelectric phase transition of powder samples. This theoretical approach provided a way of predicting the intrinsic properties of nonstoichiometric BaTiO3, which have had no previous complete determination or consideration.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134558847","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693729
N. Kim, P. Ko, Woo-Sun Lee
Metal-ferroelectric-insulator-silicon field-effect-transistors (MFISFETs) of Au/PZT/CeO2/Si were fabricated by the novel method of chemical mechanical polishing (CMP) damascene process. The vertical sidewall without the surface and/or plasma damage could be easily fabricated by it. The typical ferroelectric characteristics were sucessfully obtained although the remanent polarization value was low.
{"title":"Electrical properties of Pb(Zr,Ti)O3/CeO2/Si MFIS structure fabricated by chemical mechanical polishing (CMP) damascene process","authors":"N. Kim, P. Ko, Woo-Sun Lee","doi":"10.1109/ISAF.2008.4693729","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693729","url":null,"abstract":"Metal-ferroelectric-insulator-silicon field-effect-transistors (MFISFETs) of Au/PZT/CeO2/Si were fabricated by the novel method of chemical mechanical polishing (CMP) damascene process. The vertical sidewall without the surface and/or plasma damage could be easily fabricated by it. The typical ferroelectric characteristics were sucessfully obtained although the remanent polarization value was low.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128943165","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693895
C. Bender, A. Q. Nedelcos, J. S. Beltrones, Abel Fundora Cruz
Perovskites types Ba(Zr0.05Ti0.95)O3 (BZT) modified by Mg2+ in order to obtain Ba1-xMgx(Zr0.05Ti0.95)O3 ceramics were prepared by conventional powder mixing procedure (with x = 0.025, 0.050 and 0.075). The XRD study at the room temperature suggests ceramics have phase pseudo cubic symmetry. The behavior of the dielectric permittivity and dielectric loss measured revels that the materials are of relaxor type and undergo a diffuse type ferroelectric phase transition.
{"title":"Study of phase transition in Ba(Zr0.05Ti0.95)O3 system modified by Mg2+","authors":"C. Bender, A. Q. Nedelcos, J. S. Beltrones, Abel Fundora Cruz","doi":"10.1109/ISAF.2008.4693895","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693895","url":null,"abstract":"Perovskites types Ba(Zr0.05Ti0.95)O3 (BZT) modified by Mg2+ in order to obtain Ba1-xMgx(Zr0.05Ti0.95)O3 ceramics were prepared by conventional powder mixing procedure (with x = 0.025, 0.050 and 0.075). The XRD study at the room temperature suggests ceramics have phase pseudo cubic symmetry. The behavior of the dielectric permittivity and dielectric loss measured revels that the materials are of relaxor type and undergo a diffuse type ferroelectric phase transition.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127651205","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693899
M. Correa, A. Kumar, R. Katiyar
The disordered Lead Scandium Niobate (PSN) is a typical relaxor having high dielectric constant and dielectric maximum temperature (Tm) above room temperature. La modified samples showed shift in dielectric maxima temperature towards lower temperature side, broadening of their phase transition, and the frequency dispersion in their permittivity. However, these samples exhibit relaxor feature for up to 10% substitution but for higher values these are very diffuse in nature. Raman spectra showed a shift to lower frequencies of F2g mode and changes in the intensities and the linewidths of the dirty modes on increase in the La subtitution. The low-wave number (180 to 400 cm-1) regions showed significant change due to structural distortion with increase in the La substitution.
{"title":"Dielectric and Raman studies of La modified Lead Scandium Niobate ceramics","authors":"M. Correa, A. Kumar, R. Katiyar","doi":"10.1109/ISAF.2008.4693899","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693899","url":null,"abstract":"The disordered Lead Scandium Niobate (PSN) is a typical relaxor having high dielectric constant and dielectric maximum temperature (Tm) above room temperature. La modified samples showed shift in dielectric maxima temperature towards lower temperature side, broadening of their phase transition, and the frequency dispersion in their permittivity. However, these samples exhibit relaxor feature for up to 10% substitution but for higher values these are very diffuse in nature. Raman spectra showed a shift to lower frequencies of F2g mode and changes in the intensities and the linewidths of the dirty modes on increase in the La subtitution. The low-wave number (180 to 400 cm-1) regions showed significant change due to structural distortion with increase in the La substitution.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127423400","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 : 2008-12-02DOI: 10.1109/ISAF.2008.4693756
U. Boettger, A. Hennings, C. Kuegeler, R. Waser
A presentation is given about recent realized microwave devices using the dielectric tunability of paraelectric BST as well as the piezoelectric actuation of ferroelectric PZT.
介绍了近年来利用拟电式压电陶瓷的介电可调性和铁电式压电陶瓷的压电驱动实现的微波器件。
{"title":"Integrated BST capacitors and PZT actuators in tunable MW applications","authors":"U. Boettger, A. Hennings, C. Kuegeler, R. Waser","doi":"10.1109/ISAF.2008.4693756","DOIUrl":"https://doi.org/10.1109/ISAF.2008.4693756","url":null,"abstract":"A presentation is given about recent realized microwave devices using the dielectric tunability of paraelectric BST as well as the piezoelectric actuation of ferroelectric PZT.","PeriodicalId":228914,"journal":{"name":"2008 17th IEEE International Symposium on the Applications of Ferroelectrics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115237772","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：