激光辐照对LCMO薄膜结构和电输运特性的影响  

Effect of CO_2 Laser Irradiation on the Microstructure and Transport Properties of LCMO Thin Films

作　　者：常雷[1] 黄雅铮[1] 季凌飞[1] 蒋毅坚[1] 

机构地区：[1]北京工业大学国家产学研激光技术中心,北京100022

出　　处：《光电子．激光》2007年第9期1093-1095,1103,共4页Journal of Optoelectronics·Laser

基　　金：北京市属市管高等学校人才强教计划;北京市科技创新平台资助项目

摘　　要：利用脉冲激光溅射沉积技术,在SrTiO3(001)单晶衬底上外延生长了La0.67Ca0.33MnO3(LCMO)薄膜。采用CO2激光对制备的薄膜辐照10～60s。利用X射线衍射(XRD)、原子力显微镜(AFM)和电阻-温度测试系统对激光辐照前后的薄膜进行了对比分析。结果显示,CO2激光辐照增强了LCMO薄膜的结晶性,使薄膜呈现出类似"平原"的表面结构并降低了表面粗糙度。与传统的高温退火类似,经CO2激光辐照后,样品的电阻率从1.3mΩ·cm下降到0.5mΩ·cm,绝缘态-金属转变温度(TP)和温度电阻系数(TCR)分别从255K和7.9%·K-1提高到263K和18.7%·K-1。研究结果表明,CO2激光辐照能够在极短的时间内改善LCMO薄膜的O含量和晶粒间的连通性,从而优化和提高了薄膜的电输运特性。The effect of CO2 laser irradiation on the La0.67 Ca0. 33 MnO3 （LCMO） thin film was studied. The epitaxial thin films were prepared on single crystal SrTiO3 （001） substrates by pulsed laser deposition and irradiated for 10-60 seconds in air by using CO2 laser. The crystallinity of LCMO thin films were strongly enhanced by CO2 laser irradiation. It is found that CO2 laser irradiation results in a drarniatic decrease in the resistivity and remarkable increases in the insulator-metal transition temperature （Tp） and the temperature coeffident of resistance TCR, The significant improvements of the structure and transport are achieved in several dozens of seconds,which suggests that CO2 laser irradiation can be utilized to tune CMR manganites both fast and effectively for industrial applications.

关 键 词：脉冲激光沉积 超巨磁电阻 激光辐照 温度电阻系数(TCR) 

分 类 号：O484.4[理学—固体物理]