高等学校化学学报

高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (11): 2385.doi: 10.7503/cjcu20111115

• 研究论文: 无机化学 • 上一篇    下一篇

La1-xCaxMnO3外延薄膜的制备、结构及磁电阻效应

陈蕊1,2, 冯明1, 苟喜成1, 李海波1,2   

  1. 1. 吉林师范大学功能材料物理与化学教育部重点实验室, 四平 136000;
    2. 吉林大学无机合成与制备化学国家重点实验室, 长春 130012
  • 收稿日期:2011-11-24 出版日期:2012-11-10 发布日期:2012-10-15
  • 通讯作者: 李海波,男,博士,教授,主要从事无机纳米材料和磁性材料研究.E-mail:lihaibo@jlnu.edu.cn E-mail:lihaibo@jlnu.edu.cn
  • 基金资助:

    吉林省科技发展计划项目(批准号: 20100179)资助.

Preparation, Structure and Magnetoresistance Effect of La1-xCaxMnO3 Epitaxial Film

CHEN Rui1,2, FENG Ming1, GOU Xi-Cheng1, LI Hai-Bo1,2   

  1. 1. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Siping 136000, China;
    2. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012, China
  • Received:2011-11-24 Online:2012-11-10 Published:2012-10-15

PDF (PC)

摘要：

采用溶胶-凝胶旋涂法在单晶LaAlO3 (100)基片上生长了La1-xCaxMnO3(x=0, 0.05, 0.1, 0.2)外延薄膜. 利用X射线衍射仪(XRD)、 原子力显微镜(AFM)、 聚焦离子束系统(FIB)、 X射线光电子能谱分析仪(XPS)、 振动样品磁强计(VSM)和磁性测量系统(MPMS)对样品的结构、 形貌、 价态、 居里温度和磁电阻效应进行了研究. 结果表明, 薄膜为立方钙钛矿结构, 具有明显的(100)外延生长取向和平整的表面. 在居里温度附近, 样品发生铁磁-顺磁转变. 随着Ca2+掺杂量的增加, 样品的居里温度升高, La0.8Ca0.2MnO3的居里温度为264 K. 随温度的变化, 样品发生了金属-绝缘体转变. 样品还具有较大的磁电阻效应, 在H=2.0 T, T=210 K时, La0.95Ca0.05MnO3的磁电阻达到80.9%.

关键词: La1-xCaxMnO3外延薄膜, 溶胶-凝胶旋涂法, 居里温度, 巨磁电阻效应

Abstract:

La1-xCaxMnO3(x=0, 0.05, 0.1, 0.2) epitaxial films were grown on LaAlO3 (100) single-crystal substrate by sol-gel spin-coating method. The crystal structure, morphology, valence state, curie temperature and magnetoresistance effect of the films were investigated via X-ray diffractometer, atom force microscope, focused ion beam system, X-ray photoelectron spectrometer, vibrating sample magnetometer and superconduc-ting quantum interference device. The results show that the crystal structure of the film is cubic with high (h00)-oriented epitaxial direction and smooth surface. The maximum of Curie temperature is 264 K. Near the Curie temperature, the magnetic properties exhibit a transition from ferromagnetism to paramagnetism. The La0.95Ca0.05MnO3 film exhibit a maximum magnetoresistance ratio of 80.9% at 210 K and 2.0 T magnetic field.

Key words: La1-xCaxMnO3 epitaxial film, Sol-gel spin-coating method, Curie temperature, Colossal Magnetoresistance(CMR) effect

中图分类号: 

TrendMD: