摘要
双层钙钛矿结构的La2 - 2XSr1 +2XMn2 O7(X =0 .32 )单相薄膜生长在具有不同晶格参数的两种衬底上 .测量发现 ,两种衬底上生长的La2 - 2XSr1 +2XMn2 O7(X =0 .32 )薄膜具有迥然不同的金属-绝缘体转变温度TM -I及其他物性 .界面应力的研究表明这是衬底晶格常数不同引起膜内应变的结果 .在衬底的压应力下 ,薄膜的电阻—温度曲线的峰值 (TM -I)向高温移动且电阻率 ( ρ)下降 ;相反 ,对于衬底张应力下的薄膜 ,TM -I下降ρ上升 .这些结果可以用双交换模型做很好的解释 .
La 2-2xSr 1+2xMn 2O 7 single phase thin films are grown on two substrates with different latlice parameters.It is found that the metal-insulator fransitionis temperature and the other properties are very different for the two types of films.Study shows that the differences are dueto the strain applied by the latlicl mismatch.Under tensile strain TMI is reduced and ρ is increased. These results can be explained by double exchange model.
出处
《昆明理工大学学报(理工版)》
2002年第6期45-47,51,共4页
Journal of Kunming University of Science and Technology(Natural Science Edition)
基金
云南省科研基金 (项目编号 :1999E0 0 0 3Z) .