한국결정학회지 (Korean Journal of Crystallography)

한국결정학회 (Korean Crystallographic Association)
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Nanocrystalline Electrolytic $MnO_2$ (EMD)의 미세구조 연구

Microstructure of Nanocrystalline Electrolytic $MnO_2$ (EMD)

  • ;
  • Anqiang He (Department of Chemical & Materials Engineering, University of Alberta) ;
  • Arthur H. Heuer (Department of Materials Science & Engineering)
  • 발행 : 2003.06.01
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초록

Electrolytic MnO₂ (EMD)의 미세구조를 X선 회절 및 투과전자현미경 분석을 통해 연구하였다. 벌크에 대한 X선 회절 실험은 전헝적인 EMD 재료의 분말 회절패턴을 나타내었다. 투과전자현미경 분석은 EMD가 약 0.2㎛크기의 입자로 이루어져 있고, 각각의 입자가다시 10 nm 정도의 결정립으로 이루어진 이중 미세구조를 가짐을 나타내었다. 나노 결정립에 대한 전자빔 마이크로 회절 분석 결과, EMD 입자는 여러 상의 혼합체로서 약 50%의 Ramsdellite, 30%의 ε-MnO₂, 15%의 Pyrolusite 상으로 이루어져 있음을 확인하였다. 한편, X선 분말 회절패턴 상의 약 67°에 위치한 ｛1120｝ 피크와 (0001) 면에 대한 고분해능 이미지는 ε-MnO₂ 상의 존재를 입증하였다.

The microstructure of bulk electrolytic MnO₂ (EMD) was studied using x-ray diffraction and transmission electron microscopy (TEM). The bulk sample showed a typical powder x-ray diffraction pattern of EMD materials. TEM study showed that the structure of EMD is present at two length scales;grains, ∼0.2 ㎛ in diameter, and ∼10 nm crystallites within the grain. The electron beam microdiffraction study revealed that each grain is an assemblage of multiphase with a common crystallographic orientation, and_that ∼50% of the crystallites are Ramsdellite, ∼30% are ε-MnO₂, and ∼15% are Pyrolusite. The ｛1120｝peak located at about 67° in powder XRD pattern as well as a high-resolution electron microscope (HREM) image of (0001) plane support the existence of ε-MnO₂ phase.

키워드

참고문헌

  1. Chabre, Y. and Pannetier, J., 'Structural and Electrochemical Properties of the Proton/$\gamma$-$MnO_2$ System, Prog. Solid State Chem., 23, 1-130 (1995)
  2. Andersen, T. N., 'Effect of Some EMD Structural Features on Alkaline Discharge Capacity', Progress in Batteries and Battery Materials, 11, 105-129 (1992)
  3. Williams, R., Fredlein, R., Lawrance, G., Swinkels, D. and Ward, C., 'Effect of Deposition Conditions on the Structural, Chemical, Physical and Electrochemical Properties of EMD', Progress in Batteries and Battery Materials, 13, 102-112 (1994)
  4. de Wolff, P. M., Visser, J. W., Giovanoli, R. and Brutsch, R., '$\"{U}$ber $\varepsilon$-Mangandioxid', Chimia, 32, 257-259 (1978)
  5. Simon, D. E., Andersen, T. N. and Elliot, C. D., 'A Rietveld Refinement Model of EMD Powder Patterns', ITE Letters, 1(3), B1-B10 (2000)
  6. Heuer, A. H., He, A. Q., Hughes, P. J. and Feddrix, F. H., 'Microstructure of Electrolytic MnO2: A Transmission Electron Microscopy Study of Bulk Material', ITE Letters, 1(6), B50-B54 (2000)
  7. de Wolff, P. M., 'Interpretation of Some $\gamma$-$MnO_2$Diffraction Patterns', Acta Crystallogr., 12, 341-345 (1959)
  8. Heuer, A. H., Kim, C. H., Zhang, L. C. and He, A. Q., 'HREM Studies of Nanocrystalline Electrolytic $MnO_2$ (EMD)', Proc. of 7th Int. Symp. Adv. Phys. Fields, pp. 92-95, Tsukuba, Japan (2001)