Journal of Inorganic Materials ›› 2016, Vol. 31 ›› Issue (3): 274-278.doi: 10.15541/jim20150397

• Research Paper • Previous Articles     Next Articles

Electrical Transport Properties in La0.7Ca0.3-xSrxMnO3 Thin Films

ZHANG Yuan-Yuan1, TANG Xiao-Dong1, CHEN Ying2, WANG Gen-Shui2, DONG Xian-Lin2   

  1. (1. East China Normal University, School of Information Science Technology, Shanghai 200241, China; 2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
  • Received:2015-08-24 Revised:2015-10-28 Online:2016-03-20 Published:2016-02-24
  • Contact: TANG Xiao-Dong. E-mail:xdtang@sist.ecnu.edu.cn
  • About author:ZHANG Yuan-Yuan. E-mail: yyzhang@ee.ecnu.edu.cn
  • Supported by:

    National Natural Science Foundation of China (51302084, 11304097, 61176011, 61376129, 11374098)

Abstract:

The influence of the chemical composition on the structure, magnetic and electrical transport properties of La0.7Ca0.3-xSrxMnO3 (LCSMO, x≤0.05) thin films was systematically studied. LCSMO thin films were prepared by Sol-Gel method. XRD results show that all the films have typical perovskite structure. With increase of Sr doping concentration, both Curie temperature TC and metal-insulator transition temperature TMI of LCSMO thin films increase monotonously. When Sr doping concentration x≤0.05, with increase of temperature, absolute value of MR decreases first, then increases to a maximum value around TMI, and finally decreases, which indicates that the disorder coming from phase separation around TMI contributes greatly to MR. The field dependence of MR values at certain temperature can be classified into two kinds. When the temperature is much lower than TMI, dual gradient of MR with the magnetic field is shown. The tunneling effect on the grain boundaries plays a dominant part in the low magnetic field, and this effect is particularly sensitive to the magnetic field; the suppression of spin fluctuations by magnetic field is the main reason in the high magnetic field range. When the temperature is higher than TMI, MR of LCSMO thin films changes almost linearly with the magnetic field which is mainly due to suppression of spin fluctuations by magnetic field.

Key words: manganese oxides, Sol-Gel method, transport properties

CLC Number: 

  • TQ174