无机化学学报

层状钙钛矿型Sm_2-2xSr_1+2x-2_yCa_2yMn₂O₇(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(英文)

Sol-Gel Synthesis and Electrical Properties of Layered Perovskite Type Sm_2-2xSr_1+2x-2_yCa_2yMn₂O₇ (x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3)

作者	单位
刘佳雯	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
陈刚	哈尔滨工业大学应用化学系，哈尔滨 150001
李中华	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
迟欣	哈尔滨工业大学物理系，哈尔滨 150001
张治国	哈尔滨工业大学物理系，哈尔滨 150001

摘要:

关键词: 溶胶-凝胶合成层状钙钛矿电性能

基金项目:

Abstract: Layered perovskite manganites with a nominal chemsitry of Sm_2-2xSr_1+2x-2_yCa_2yMn₂O₇(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 e_g bandwidth.

Keywords: sol-gel synthesis layered perovskite electrical property

摘要点击次数: 1355

全文下载次数: 1681

刘佳雯,陈刚,李中华,迟欣,张治国.层状钙钛矿型Sm_2-2xSr_1+2x-2_yCa_2yMn₂O₇(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(英文)[J].无机化学学报,2006,22(4):705-708.

查看全文查看/发表评论下载PDF阅读器

Support information: