Electrical transport properties of Sm-doped La0.7Ca0.3MnO3 polycrystalline ceramics. Issue 18 (15th September 2021)

• Record Type: Journal Article
• Authors: Wang, Chengyi; Li, Yule; Sun, Peng; Yang, Sheng'an; Zhang, Hui; Chen, Qingming
• Is Part Of: Ceramics international. Volume 47:Issue 18(2021)
• Page Start: 25281
• Page End: 25286
• Publication Date: 2021-09-15
• Subjects: La0.7-xSmxCa0.3MnO3 (LSCMO) -- Temperature coefficient of resistance (TCR) -- Resistivity (ρ) -- Sol–gel method -- Magnetoresistance (MR); Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.05.249
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Improving the magnetoresistance effect of perovskite ceramic materials under a low applied magnetic field to expand its application range is one of the main research directions of this type of material. In this study, La0.7 Ca0.3 MnO3 was doped with different levels of Sm by the sol-gel method to yield a series of La0.7-x Smx Ca0.3 MnO3 (LSCMO) polycrystalline ceramics. X-ray diffraction (XRD) results revealed that LSCMO ceramics possessed standard perovskite structures. Scanning electron microscopy (SEM) showed grains closely connected without obvious holes. In addition, the grain size gradually decreased with the increase in Sm doping content. The resistivity temperature curves displayed a clear metal-insulator transition behavior of LSCMO accompanied by a steep change from ferromagnetic to paramagnetic behavior (FM-PM). The metal-insulator transition temperature ( T p ) values of the as-obtained LSCMO gradually shifted toward lower temperatures with increase in Sm content. Moreover, resistivity temperature coefficient ( TCR ) and magnetoresistance ( MR ) values also gradually increased with Sm doping content. The transport properties in polycrystalline ceramics could be adequately explained by the double exchange model, which would be useful for interpreting the CMR effects when used in magnetic devices.