Proceedings of the Korean Magnestics Society Conference (한국자기학회:학술대회 개요집)

  • 2009.12a
  • /
  • Pages.192-192
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  • 2009
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  • 2233-9485(pISSN)
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  • 2233-9574(eISSN)
The Korean Magnetics Society (한국자기학회)
권호 표지

Magnetic and Magnetotransport Properties of (1-x) $La_{0.7}Sr_{0.3}MnO_3-xRE_2O_3$ (RE=La, Nd) Composites

  • Kim, Hyo-Jin (Department of Materials Science and Engineering, Research institute of advanced material(RIAM), Seoul National University) ;
  • Kang, Young-Min (Department of Materials Science and Engineering, Research institute of advanced material(RIAM), Seoul National University) ;
  • Yoo, Sang-Im (Department of Materials Science and Engineering, Research institute of advanced material(RIAM), Seoul National University)
  • Published : 2009.12.06
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Abstract

Magnetic and magnetotransport properties of (1-x) $La_{0.7}Sr_{0.3}MnO_3-xRE_2O_3$ (RE=La, Nd) (x = 0.025, 0.05, 0.075, 0.1, 0.2, 0.3) composite polycrystalline samples were systematically studied. Samples were prepared using conventional solid-state reaction. LSMO and $RE_2O_3$ react at high temperature and become chemically compatible. The ferromagnetic-paramagnetic transition temperatures ($T_c$) of the LSMO-$Nd_2O_3$ composite samples were decreased 313K~349K with increasing x, while the $T_c$ values of the LSMO-$La_2O_3$ composite samples were almost unaltered in the range of 355K~358K, representing that the ferromagnetism of LSMO might be more seriously degraded by Nd substitution on the ($La_{0.7}Sr_{0.3}$) site. However, LSMO-$RE_2O_3$ composite samples exhibit greatly enhanced low field magnetoresistance (LFMR) and dMR/dH value without an appreciable increase in its resistivity. Remarkably improved LFMR properties are attributed to LSMO grain boundaries acting as effective spin-dependent scattering centers. The relationship among the $RE_2O_3$ addition, microstructure, magnetic and magnetotransport properties will be discussed in this paper.

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