La_(0.9)Na_(0.1)MnO_3的反常超声特性  

ULTRASONIC ANOMALIES IN La_(0.9)Na_(0.1)MnO_3 NEAR THE CURIE TEMPERATURE

作　　者：谢津桥[1] 吴鸿毅[1] 苏金瑞[1] 钱天[1] 朱长飞[1] 

机构地区：[1]中国科学技术大学材料科学与工程系,内耗与固体缺陷重点实验室,合肥230026

出　　处：《低温物理学报》2002年第4期298-302,共5页Low Temperature Physical Letters

摘　　要：系统地测量了La0 .9Na0 .1 MnO3单相陶瓷样品的电阻、磁化率、超声声速和衰减随温度的变化关系 ,发现在 2 4 5K附近体系发生顺磁绝缘体 铁磁金属相变 ,同时超声声速出现剧烈的软化现象 ,其相对变化超过 2 % .超声衰减也出现一个尖锐的衰减峰 .经分析认为这些发生在Curie温度附近的反常超声现象 ,可能是由自旋 声子和电Temperature dependence of resistance, magnetization, ultrasonic velocity and attenuation for single phase polycrystalline sample of La-{0.9}Na-{0.1}MnO-3 were measured. It is observed that near 245K there is a phase transition from paramagnetic insulator to ferromagnetic metal. A dramatic increase, near 2%, in ultrasonic velocity is observed at the same time, and accompanied by a sharp attenuation peak. This simultaneous occurrence of magnetic, transport, and lattice anomalous features implies extremely strong spin-phonon and electron-phonon interaction in La-{0.9}Na-{0.1}MnO-3 system.

关 键 词：La0.9Na0.1MnO3 反常超声特性 钙钛矿锰氧化物 单相陶瓷 

分 类 号：O513[理学—低温物理]