Positron lifetime study of Pr1-xCaxMnO3 (x=0.5, 0.3) during magnetic transition

被引:1
作者
Tomioka, Y. [1 ]
Koshimizu, M. [1 ]
Asai, K. [1 ]
机构
[1] Tohoku Univ, Grad Sch Engn, Dept Appl Chem, Aoba Ku, Sendai, Miyagi 9808579, Japan
关键词
Pr1-xCaxMnO3; Perovskite manganite; Positron annihilation lifetime; Vacancy; Magnetism; Antiferromagnetism; EXCHANGE;
D O I
10.1016/j.radphyschem.2009.05.004
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We measured the positron lifetime in perovskite manganites Pr1-xCaxMnO3 (x = 0.3. 0.5). Two lifetime components were observed for each compound; they were attributed to the annihilation of free positrons and positrons trapped at the A-site vacancies. The positron lifetime at the A-site vacancies changed significantly during the antiferromagnetic transition in both the compounds, whereas it was constant around the charge-ordering transition. This change indicates that the electron distribution at the vacancies changed possibly due to the change in the electron distribution of neighboring oxygen atoms. This result indicates that positron lifetime measurements can provide unique information on electronic states during a spin-related phase transition in various oxide materials. (C) 2009 Elsevier Ltd. All rights reserved.
引用
收藏
页码:1092 / 1095
页数:4
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