Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Structural Elucidation and Magnetical Properties of La0.5Ca0.5MnO3 Powders and Pellets

La0.5Ca0.5MnO3 분말과 Pellet의 구조분석 및 자기적 성질

  • Jung, Miewon (Department of Chemistry, Sungshin Women's University) ;
  • Lee, Jiyun (Department of Chemistry, Sungshin Women's University) ;
  • Kim, Hyunjung (Department of Chemistry, Sungshin Women's University)
  • Received : 2004.02.04
  • Accepted : 2004.10.15
  • Published : 2005.02.28
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Abstract

$La_{0.5}Ca_{0.5}MnO_3$ colossal magnetoresistance (CMR) powders and pellets were synthesized by sol-gel process. The structural changes were investigated by FT-IR, CP/MAS $^{13}C$ solid state NMR spectroscopy and XRD. The particle characterization, microstructure of sintered samples, and cation composition of gel powders were studied by FE-SEM/EDS, TEM and ICP-AES. The structure refinement reveals that $La_{0.5}Ca_{0.5}MnO_3$ has orthorhombic, perovskite type unit cell. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

초거대 자기 저항 물질인 $La_{0.5}Ca_{0.5}MnO_3$의 분말과 pellet을 졸-겔 법으로 제조하였다. 열처리 온도를 변화시켜 얻은 시료에 대해 FT-IR과 CP/MAS $^{13}C$ solid state NMR spectroscopy 그리고 XRD 등을 이용해 구조변화를 관찰하였다. 양이온 조성 비율을 알아보기 위해 ICP-AES를 이용하였으며, 입자크기와 균일도를 FE-SEM/EDS로, 미세구조와 격자 패턴은 TEM으로 관찰하였다. VSM을 이용하여 자기적 특성을 살펴보았으며 큐리온도($T_c$)는 236 K에서 측정되었다.

Keywords

References

  1. Tokura, Y. and Tomioka, Y., 'Colossal Magnetoresistive Manganites,' J. Magn. Magn. Mater., 200(1), 1-23(1999) https://doi.org/10.1016/S0304-8853(99)00352-2
  2. Kwon, S. W., Park, S. B., Seo, G. and Hwang, S. T., 'Preparation of Lithium Aluminate via Polymeric Precursor Routes,' J. Nuclear Materials., 257(2), 172-179(1998) https://doi.org/10.1016/S0022-3115(98)00442-5
  3. Hervieu, M., Van Tendeloo, G., Caignaert, V., Maignan, A. and Raveau, B., 'Monoclinic Microdomains and Clustering in the Colossal Magnettoresistance Manganites $Pr_{0.7}Ca_{0.25}Sr_{0.05}MnO_3\;and\; Pr_{0.75}Sr_{0.25}MnO_3$,' Phys. Rev. B: Condens. Matter., 53(21), 14274-14284(1996) https://doi.org/10.1103/PhysRevB.53.14274
  4. Kajinara, K. C. and Yao, T., 'Macroporous Morphology of the Titania Films Prepared by a Sol-Gel Dip-Coating Method from the System Containing Poly (Ethylene Glycol). III. Effect of Chemical Additives,' J. Sol-Gel Sci. and Tech., 16, 257-266(1999) https://doi.org/10.1023/A:1008721320860
  5. Shimizu, Y. and Murata, T., 'Sol-Gel Synthesis of Perovskite Type Lanthanum Manganite Thin Films and Fine Powders using Metal Acetylacetonate and Poly(vinyl alcohol),' J. Am. Ceram. Soc., 80(10), 2702-2704(1997) https://doi.org/10.1111/j.1151-2916.1997.tb03178.x
  6. Li, X., Zhang, H., Chi, F., Li, S., Xu, B. and Zhao, M., 'Synthesis of Nanocrystalline Composite Oxides $La_{1-x}Sr_xFe_{1-y}Co_yO_3$ with the Perovskite Structure using Poly (ethylene glycol) Gel Method,' Mater. Sci and Eng. B., 18(3), 209-213(1993) https://doi.org/10.1016/0921-5107(93)90133-8
  7. Park, H. B., Kweon, H. J., Kim, S. J. and Kim, K., 'Preparation of $LaMO_3$ (M: Cr, Mn, Co) Fine Powders using PEG,' J. Kor. Chem. Soc., 38(11), 852-855(1994)
  8. Jung, M. W., Lee, J. Y. and Kim, H. J., 'Preparation and Characterization of $La_{0.8}Ca_{0.2}MnO_3$,' J. Kor. Ceram. Soc., 40(5), 434-440(2003) https://doi.org/10.4191/KCERS.2003.40.5.434
  9. Bilger, S., Syskakis, E., Naoumidis, A. and Nickel, H., 'Sol-Gel Synthesis of Strontium-Doped Lanthanum Managanite,' J. Am. Ceram. Soc., 75(4), 964-970(1992) https://doi.org/10.1111/j.1151-2916.1992.tb04167.x
  10. Chen, C. H. and Cheong, S-W., 'Commensurate to Incommensurate Charge Ordering and its Real-Space Images in $La_{0.5}Ca_{0.5}MnO_3$', Phys. Rev. Lett., 76(21), 4042-4045(1996) https://doi.org/10.1103/PhysRevLett.76.4042
  11. Radaelli, P. G., Cox, D. E., Marezio, M. and Cheong, S.-W., 'Charge, Orbital, and Magnetic Ordering in $La_{0.5}Ca_{0.5}MnO_3$', Phys. Rev. B., 55(5), 3015-3023(1997) https://doi.org/10.1103/PhysRevB.55.3015
  12. Rao, C. N. R., Cheetham, A. K. and Mahesh, R., 'Giant Magnetoresistance and Related Properties of Rare-Earth Manganates and Other Oxide Systems,' Chem. Mater., 8(10), 2421-2432(1996) https://doi.org/10.1021/cm960201v
  13. Mori, S., Chen, C. H. and Cheong, S-W., 'Paired and Unpaired Charge Stripes in the Ferromagnetic Phase of $La_{0.5}Ca_{0.5}MnO_3$,' Phys. Rev. Lett., 81(18), 3972-3975(1998) https://doi.org/10.1103/PhysRevLett.81.3972