La_(0.7)Sr_(0.3)MnO_3外延膜缺陷性质的慢正电子束研究  

DEFECT PROPERTIES OF THE La_(0.7)Sr_(0.3)MnO_3 EPITAXIAL FILMS STUDIED BY VARIABLE ENERGY POSITRON BEAM

作　　者：金绍维[1] 顾伟伟[1] 周先意[1] 吴文彬[2] 翁惠民[1] 朱长飞[3] 叶邦角[1] 韩荣典[1] 

机构地区：[1]中国科学技术大学近代物理系,合肥230027 [2]中国科学技术大学结构分析重点实验室,合肥230026 [3]中国科学技术大学材料科学与工程系,合肥230026

出　　处：《低温物理学报》2004年第2期95-100,共6页Low Temperature Physical Letters

基　　金：国家自然科学基金 (项目编号 :10 175 0 6 1)资助的课题~~

摘　　要：用单能慢正电子束 ,测量了不同氧分压下生长的La0 .7Sr0 .3MnO3外延膜的S参数与入射正电子能量E的关系 .结果发现La0 .7Sr0 .3MnO3外延膜中S参数与氧分压是非单调变化的 ;这与沉积氧分压的两种作用相关联的 .在氧分压较高的LSMO薄膜中 ,空位浓度的增加主要是由沉积原子 (离子 )与氧原子碰撞几率增大 ,使其缺乏足够的动能去填补空位引起的 ;在低氧分压的LSMO薄膜中 ,空位浓度的增大则主要是提供成膜所需要的氧原子缺乏 。By using a variable energy positron beam system, the linear S parameter as a function of implantation positron energy was measured on the epitaxial La-{0.7}Sr-{0.3}MnO-3 thin-films from different deposition oxygen pressures. It is found that the relationship between the S parameters of the epitaxial La-{0.7}Sr-{0.3}MnO-3 films and oxygen pressures is not monotonous. This relationship is related to the actions of the deposition oxygen pressure. For the La-{0.7}Sr-{0.3}MnO-3 film was prepared by the high growth oxygen pressure, the increase of the vacancy concentration is caused from the large collision faction of the deposition atom and oxygen atom. In contrast, for the film prepared by the low growth oxygen pressure, the increase of the vacancy concentration is caused from the oxygen atom deficiency during the film growth and resulted in the oxygen vacancies and the related defect complexes.

关 键 词：锰酸锶镧 外延薄膜 增电子湮灭 单能慢正电子束 氧分压 薄膜缺陷 空位浓度 

分 类 号：O484[理学—固体物理]