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| 层状钙钛矿型Sm2-2xSr1+2x-2yCa2yMn2O7(x=0.2，0.3，0.4，0.5；y=0，0.2，0.3)的溶胶凝胶合成及电性能研究 | |
| 引用本文： | 刘佳雯,陈 刚,李中华,迟 欣,张治国.层状钙钛矿型Sm2-2xSr1+2x-2yCa2yMn2O7(x=0.2，0.3，0.4，0.5；y=0，0.2，0.3)的溶胶凝胶合成及电性能研究[J].无机化学学报,2006,22(4):705-708. |
| 作者姓名： | 刘佳雯 陈 刚 李中华 迟 欣 张治国 |
| 作者单位： | 1. 哈尔滨工业大学物理系,哈尔滨,150001;哈尔滨工业大学应用化学系,哈尔滨,150001 2. 哈尔滨工业大学应用化学系,哈尔滨,150001 3. 哈尔滨工业大学应用化学系,哈尔滨,150001;吉林大学无机合成与制备化学国家重点实验室,长春,130023 4. 哈尔滨工业大学物理系,哈尔滨,150001 |
| 基金项目： | 中国科学院资助项目;哈尔滨工业大学校科研和教改项目 |
| 摘 要： | Layered perovskite manganites with a nominal chemsitry of Sm2-2xSr1+2x-2yCa2yMn2O7(x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3) were prepared using sol-gel method. The crystal structures of these compounds were studied by X-ray diffraction (XRD) and FTIR absorption spectra. The absorption peaks become weaker and move a little to higher frequency with increasing of Sm/Sr concentration. As the Sm doping increases to x=0.2 and x=0.3, the absorption peaks show a cubic structure character, reflecting that the samples suffer from a transition from tetragonal structure to cubic structure. This coincides with the X-ray diffraction results. The high temperature electrical properties were studied by conventional four-probe method. Although all samples exhibit the semiconductive behavior, lnρ-1 000/T curves are not linear and they obey the small polaron hopping mechanism. Moreover, the resistivity decreases with x reducing. This is due to that Sm doping increases the Jahn-Teller ion Mn3+/Mn4+ ratio, and decreases the eg bandwidth. |
| 关 键 词： | 溶胶-凝胶合成 层状钙钛矿 电性能 |
| 文章编号： | 1001-4861(2006)04-0705-04 |
| 收稿时间： | 2005-09-12 |
| 修稿时间： | 2006-03-01 |
Sol-Gel Synthesis and Electrical Properties of Layered Perovskite Type Sm2-2xSr1+2x-2yCa2yMn2O7 (x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3) |
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| LIU Jia-Wen,CHEN Gang,LI Zhong-Hu,CHI Xin and ZHANG Zhi-Guo.Sol-Gel Synthesis and Electrical Properties of Layered Perovskite Type Sm2-2xSr1+2x-2yCa2yMn2O7 (x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3)[J].Chinese Journal of Inorganic Chemistry,2006,22(4):705-708. | |
| Authors: | LIU Jia-Wen CHEN Gang LI Zhong-Hu CHI Xin and ZHANG Zhi-Guo |
| Institution: | Department of Physics, Harbin Institute of Technology, Harbin 150001;Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001,Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001,Department of Physics, Harbin Institute of Technology, Harbin 150001;State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023,Department of Physics, Harbin Institute of Technology, Harbin 150001 and Department of Physics, Harbin Institute of Technology, Harbin 150001 |
| Abstract: | Layered perovskite manganites with a nominal chemsitry of Sm2-2xSr1+2x-2yCa2yMn2O7 (x=0.2, 0.3, 0.4, 0.5;y=0, 0.2, 0.3) were prepared using sol-gel method. The crystal structures of these compounds were studied by Xray diffraction (XRD) and FTIR absorption spectra. The absorption peaks become weaker and move a little to higher frequency with increasing of Sm/Sr concentration. As the Sm doping increases to x=0.2 and x=0.3, the absorption peaks show a cubic structure character, reflecting that the samples suffer from a transition from tetragonal structure to cubic structure. This coincides with the X-ray diffraction results. The high temperature electrical properties were studied by conventional four-probe method. Although all samples exhibit the semiconductive behavior, lnρ-1000/T curves are not linear and they obey the small polaron hopping mechanism. Moreover, the resistivity decreases with x reducing. This is due to that Sm doping increases the Jahn-Teller ion Mn3+/Mn4+ ratio,and decreases the eg bandwidth. |
| Keywords: | sol-gel synthesis layered perovskite electrical property |
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