Elastic anomalies in the perovskite manganite La0.5Ca0.5MnO3

被引：8

作者：

Chen, C. X. ^{[1
]}

Zheng, J. Y. ^{[1
]}

Jiang, Y. Y. ^{[1
]}

Li, J. ^{[1
]}

Zheng, R. K. ^{[2
]}

机构：

[1] Anqing Normal Coll, Dept Phys & Elect Engn, Anqing 246003, Anhui, Peoples R China

[2] Univ Sci & Technol China, Dept Mat Sci & Engn, Hefei 230026, Anhui, Peoples R China

来源：

PHYSICA B-CONDENSED MATTER | 2010年 / 405卷 / 08期

关键词：

Manganites; Charge ordering; Longitudinal modulus; Low-frequency shear modulus; Jahn-Teller effect; CHARGE; TEMPERATURE;

D O I：

10.1016/j.physb.2010.01.108

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The temperature dependence of the elastic properties of polycrystalline manganites La0.5Ca0.5MnO3 has been studied by means of ultrasonic measurements and low-frequency internal friction apparatus. It was found that both the longitudinal modulus and the low-frequency shear modulus starts to soften obviously with a decrease in temperature from higher temperature to the charge-ordering transition temperature T-CO and stiffens dramatically just below T-CO. The abnormal temperature dependence of the elastic modulus around T-CO is fitted with the mean-field theory, which describes the coupling of Jahn-Teller ions to distortions of lattice of the cooperative Jahn-Teller system. The good fit of the theory to the data indicates that the Jahn-Teller effect is the dominant mechanism responsible for the charge-ordering state of the system. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：2088 / 2090

页数：3