东北大学学报:自然科学版 ›› 2014, Vol. 35 ›› Issue (3): 366-368.DOI: 10.12068/j.issn.1005-3026.2014.03.014

• 材料与冶金 • 上一篇    下一篇

La1-xSrxMnO3体系中Mn3O4微孪晶表征

孙本哲,祁阳   

  1. (东北大学 理学院, 辽宁 沈阳110819)
  • 收稿日期:2013-05-27 修回日期:2013-05-27 出版日期:2014-03-15 发布日期:2013-11-22
  • 通讯作者: 孙本哲
  • 作者简介:孙本哲(1976-),男,辽宁抚顺人,东北大学副教授;祁阳(1960-),男,辽宁沈阳人,东北大学教授,博士生导师.
  • 基金资助:
    中央高校基本科研业务费专项资金资助项目(N090405002).

Characterization of the Microtwinning of Mn3O4 in La1xSrxMnO3 Compounds

SUN Benzhe, QI Yang   

  1. School of Sciences, Northeastern University, Shenyang 110819, China.
  • Received:2013-05-27 Revised:2013-05-27 Online:2014-03-15 Published:2013-11-22
  • Contact: QI Yang
  • About author:-
  • Supported by:
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摘要: La1xSrxMnO3(LSMO)锰氧化物由于具有显著的庞磁电阻效应而被广泛关注,但少量Mn3O4杂质相会破坏其磁电阻效应.采用透射电子显微术及其相关分析方法,系统表征了杂质相Mn3O4中的微孪晶结构,并分析其形成机制.研究发现,在具有锐钛矿结构的Mn3O4中,微孪晶的孪晶面为(112)面,且孪晶面附近含有少量Sr原子;孪晶面出现几率与Sr原子含量之间的关系表明,孪晶的形成归因于少量Sr原子降低了孪晶界面形成能,这有助于推测出从锐钛矿向钙钛矿发生结构演化的一般规律.

关键词: 庞磁电阻效应, 透射电子显微术, 微孪晶, 孪晶面, 孪晶界面形成能

Abstract: La1xSrxMnO3 (LSMO) manganite has been widely focused on due to its significant colossal magnetoresistance (CMR) effect, but a trace of impurity Mn3O4 suppresses the CMR effect. The microtwinning in Mn3O4 phase was characterized and its formation mechanism was analyzed systematically by means of transmission electron microscopy and the relative analytical methods. It was found that twin plane is defined as (112) and a small amount of Sr atoms are observed near the twin plane in Mn3O4 with anatase structure.Based on the relationships between the probability of microtwinning and the number of Sr atoms, it can be verified that the formation of microtwinning may be attributed to the decrease in the formation energy of twin boundary induced by the introduction of Sr atoms, which contributes to deduce the general rule on the structural evolution from anatase to perovskite.

Key words: colossal magnetoresistance effect, transmission electron microscopy, microtwinning, twin plane, formation energy of twin boundary

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