低含量La_(1-x)Ca_xMnO_3的电输运及超声衰减性质  

Electric Transport Property and Ultrasonic Behavior of La_(1-X)Ca_xMnO_3 with Low Doping Level

作　　者：黄晓桦[1,2] 林洪沂[1,2] 孟宪国[1,2] 李爱玉[1,2] 

机构地区：[1]厦门理工学院光电与通信工程学院,福建厦门361024 [2]福建省高校光电技术重点实验室,福建厦门361024

出　　处：《厦门理工学院学报》2013年第2期52-55,共4页Journal of Xiamen University of Technology

基　　金：厦门理工学院高层次引进人才科技项目(YJK10014R;YJK10011R)

摘　　要：为研究钙钛矿锰氧化物中电-声子耦合作用,采用共沉淀法制备La1-xCaxMnO3(0.25≤x≤0.45)块材.利用Keithley 220可编程电阻测量系统、超声衰减测量系统、超导量子干涉仪等,系统研究了体系的电输运行为和超声衰减性质.结果表明:体系的铁磁相变温度、金属-绝缘转变温度以及出现超声衰减行为异常的温度相近,室温下声速相对变化值大于1%.这是Zener双交换作用机制和电-声子耦合共同作用的结果.The bulk samples La1-xCaxMnO3（0.25≤x≤0.45） were prepared by a coprecipitation method, and the transport property and ultrasonic behaviour were studied systemically. The results show that the metal -insulator transition temperatures approximate to the ferromagnetic transition ones where both the sound velocity and attenuation display abnormal behaviours for almost all of the samples, and a velocity increase of more than 1% appears at room temperature. It is suggested that the double exchange mechanism demonstrated by Zener and electron -phonon interaction play important roles in these results.

关 键 词：La1-xCaxMnO3 超声衰减 电输运 铁磁转变 电-声子耦合 

分 类 号：O482.54[一般工业技术—材料科学与工程]