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비정질 알칼리 규산염 원자구조의 철 함량 효과에 관한 고체 NMR 분광학 연구

김효임;이성근
Kim, Hyo-Im;Lee, Sung-Keun

  • 투고 : 2011.12.10
  • 심사 : 2011.12.23
  • 발행 : 2011.12.31

초록

철을 포함한 비정질 규산염 용융체의 원자 구조 규명은 지표 환경의 화성활동 및 맨틀 심부의 초저속도층의 속도구조에 이르는 광범위한 지질과정의 미시적인 원인에 대한 단서를 제공한다. 본 연구에서는 철을 포함한 비정질 규산염의 원자 구조 규명에 가장 적합한 고상 핵자기공명분광분석(NMR)을 이용하여 최대 16.07 wt%의 $Fe_2O_3$가 포함된 비정질 알칼리 규산염(iron-bearing alkali silicate glasses)의 철의 함량 변화가 원자구조에 미치는 영향을 규명하였다. $^{29}Si$ 스핀-격자 완화시간($T_1$)을 측정한 결과, 철의 함량에 따라 스핀-격자 완화시간이 짧아지는데 이는 철이 가지고 있는 홀전자(unpaired electron)와 핵 스핀(nuclear spin)간의 상호작용으로부터 기인한다. $^{29}Si$ MAS NMR 실험 결과, 철이 포함되지 않은 시료의 경우 $Q^2$, $Q^3$ 그리고 $Q^4$의 환경을 지시하는 피크가 분리됨에 반하여, 철이 포함된 시료의 경우 NMR 신호의 급격한 감소와 피크 폭이 넓어짐으로써 각각의 규소 환경이 거의 분리되지 않았다. 그러나 철의 함량에 따라 스펙트럼이 넓어지고 화학적 차폐값(chemical shift)이 높아지는 현상을 확인하였는데, 이는 $Q^4$의 규소 환경을 나타내는 방향으로서 철 주변의 $Q^n$이 불균질하게 분포하고 있음을 지시한다. $^{17}O$ MAS NMR 실험에서도 철이 포함되지 않은 시료에서는 연결산소(Si-O-Si)와 비연결산소(Na-O-Si)가 부분적으로 분리되지만, 철의 함량이 증가하면서 각각의 산소 환경이 거의 분리되지 않는다. 이러한 연구결과는 고상 핵자기공명분광분석이 철을 포함한 비정질 규산염의 상세한 구조 연구에 효과적인 도구임을 지시한다.

키워드

철을 포함한 비정질 규산염;$^{29}Si$;$^{17}O$ 핵자기공명분광분석;원자구조;$^{29}Si$ 스핀-격자 완화시간

참고문헌

  1. 박선영과 이성근 (2009) 다성분계 현무암질 비정질 규산염의 원자 구조에 대한 고상핵자기 공명 분광분석연구. 한국광물학회지, 22, 343-352.
  2. 이성근 (2005) 2차원 고상 핵자기 공명기를 이용한 비정질 규산염의 고압구조 및 무질서도에 대하여. 한국광물학회지, 18, 45-52
  3. Bouhifd, M.A., Richet, P., Besson, P., Roskosz, M., and Ingrin, J. (2004) Redox state, microstructure and viscosity of a partially crystallized basalt melt. Earth. Planet. Sci. Lett., 218, 31-44. https://doi.org/10.1016/S0012-821X(03)00641-1
  4. Brown, G.E., Farges, F., and Calas, G. (1995) X-ray scattering and x-ray spectroscopy studies of silicate melts. Rev. Mineral., 32, 317-410.
  5. Calas, G. and Petiau, J. (1983) Coordination of iron in oxide glasses through high-resolution K-edge spectra - information from the pre-edge. Solid State Commun., 48, 625-629. https://doi.org/10.1016/0038-1098(83)90530-6
  6. Dingwell, D.B. and Virgo, D. (1987) The effect of oxidation-state on the viscosity of melts in the system $Na_{2}O$-FeO-$Fe_{2}O_{3}$-$SiO_{2}$. Geochim. Cosmochim. Acta., 51, 195-205. https://doi.org/10.1016/0016-7037(87)90231-6
  7. Dingwell, D.B. (1989) Shear viscosities of ferrosilicate liquids. Am. Miner., 74, 1038-1044.
  8. Dingwell, D.B. (1991) Redox viscometry of some Fe-bearing silicate melts. Am. Miner., 76, 1560-1562.
  9. Frydman, L. and Harwood, J.S. (1995) Isotropic spectra of half-integer quadrupolar spins from bidimensional magic-angle-spinning NMR. J. Am. Chem. Soc., 117, 5367-5368. https://doi.org/10.1021/ja00124a023
  10. Hartman, J.S. and Sherriff, B.L. (1991) Si-29 MAS NMR of the aluminosilicate mineral kyanite - residual dipolar coupling to Al-27 and nonexponential spin-lattice relaxation. J. Phys. Chem., 95, 7575-7579. https://doi.org/10.1021/j100173a005
  11. Herzberg, C. (2006) Petrology and thermal structure of the Hawaiian plume from Mauna Kea volcano. Nature, 444, 605-609. https://doi.org/10.1038/nature05254
  12. Idehara, K. (2011) Structural heterogeneity of an ultra- low-velocity zone beneath the Philippine Islands: Implications for core-mantle chemical interactions induced by massive partial melting at the bottom of the mantle. Phys. Earth. Planet. In., 184, 80-90. https://doi.org/10.1016/j.pepi.2010.10.014
  13. Kelsey, K.E., Stebbins, J.F., Du, L.S., Mosenfelder, J.L., Asimow, P.D., and Geiger, C.A. (2008) Cation order/disorder behavior and crystal chemistry of pyrope-grossular garnets: An O-17 3QMAS and Al-27 MAS NMR spectroscopic study. Am. Miner., 93, 134-143. https://doi.org/10.2138/am.2008.2623
  14. Kelsey, K.E., Stebbins, J.F., Singer, D.M., Brown, G.E., Mosenfelder, J.L., and Asimow, P.D. (2009) Cation field strength effects on high pressure aluminosilicate glass structure: Multinuclear NMR and La XAFS results. Geochim. Cosmochim. Acta, 73, 3914-3933. https://doi.org/10.1016/j.gca.2009.03.040
  15. Kim, H. and Lee, S.K. (2011) Probing atomic structures of iron-bearing alkali silicate glasses using solid-state NMR, in preparation.
  16. Lange, R.A. and Navrotsky, A. (1992) Heat-capacities of $Fe_{2}O_{3}$-bearing silicate liquids. Contrib. Mineral. Petr., 110, 311-320. https://doi.org/10.1007/BF00310746
  17. Lee, S.K. (2005) Microscopic origins of macroscopic properties of silicate melts and glasses at ambient and high pressure: Implications for melt generation and dynamics. Geochim. Cosmochim. Acta, 69, 3695-3710. https://doi.org/10.1016/j.gca.2005.03.011
  18. Lee, S.K. and Stebbins, J.F. (1999) The degree of aluminum avoidance in aluminosilicate glasses. Am. Miner., 84, 937-945. https://doi.org/10.2138/am-1999-5-630
  19. Lee, S.K. and Stebbins, J.F. (2006) Disorder and the extent of polymerization in calcium silicate and aluminosilicate glasses: O-17 NMR results and quantum chemical molecular orbital calculations. Geochim. Cosmochim. Acta, 70, 4275-4286. https://doi.org/10.1016/j.gca.2006.06.1550
  20. Lee, S.K. and Stebbins, J.F. (2009) Effects of the degree of polymerization on the structure of sodium silicate and aluminosilicate glasses and melts: An O-17 NMR study. Geochim. Cosmochim. Acta, 73, 1109-1119. https://doi.org/10.1016/j.gca.2008.10.040
  21. Lee, S.K. and Sung, S. (2008) The effect of network- modifying cations on the structure and disorder in peralkaline Ca-Na aluminosilicate glasses: O-17 3QMAS NMR study. Chem. Geol., 256, 326-333. https://doi.org/10.1016/j.chemgeo.2008.07.019
  22. Levitt, M.H. (2001) Spin dynamics: Basic of Nuclear Magnetic Resonance (NMR). John Wiley & Sons, LTD, Chichester.
  23. Liebske, C., Behrens, H., Holtz, F., and Lange, R.A. (2003) The influence of pressure and composition on the viscosity of andesitic melts. Geochim. Cosmochim. Acta, 67, 473-485. https://doi.org/10.1016/S0016-7037(02)01139-0
  24. Lussier, A.J., Aguiar, P.M., Michaelis, V.K., Kroeker, S., and Hawthorne, F.C. (2009) The occurrence of tetrahedrally coordinated Al and B in tourmaline: An $^{11}B$ and $^{27}Al$ MAS NMR study. Am. Miner., 94, 785-792. https://doi.org/10.2138/am.2009.3000
  25. Maekawa, H., Maekawa, T., Kawamura, K., and Yokokawa, T. (1991) The structural groups of alkali silicate-glasses determined from Si-29 MAS NMR. J. Non-Cryst. Solids, 127, 53-64. https://doi.org/10.1016/0022-3093(91)90400-Z
  26. Mysen, B.O., Virgo, D., and Seifert F.A. (1984) Redox equilibria of iron in alkaline earth silicate melts: relationships between melt structure, oxygen fugacity, temperature and properties of iron-bearing silicate liquids. Am. Miner., 69, 834-847.
  27. Mysen, B.O. and Richet, P. (2005) Silicate Glasses and Melts: Properties and Structure Developments in Geochemistry 10, Elsevier.
  28. Mysen, B.O., Virgo, D., Neumann, E.R., and Seifert, F.A. (1985a) Redox equilibria and the structural states of ferric and ferrous iron in melts in the system CaO-MgO-$Al_{2}O_{3}$-$SiO_{2}$-Fe-O relationships between redox equilibria, melt structure and liquidus phase-equilibria. Am. Miner., 70, 317-331.
  29. Mysen, B.O., Virgo, D., Scarfe, C.M., and Cronin, D.J. (1985b) Viscosity and structure of iron-bearing and aluminum-bearing calcium silicate melts at 1 atm. Am. Miner., 70, 487-498.
  30. Mysen, B.O., Virgo, D., and Seifert, F.A. (1985c) Relationships between properties and structure of aluminosilicate melts. Am. Miner., 70, 88-105.
  31. Mysen, B.O. and Virgo, D. (1985) Iron-bearing silicate melts: relations between pressure and redox equilibria. Phys. Chem. Minerals, 12, 191-200. https://doi.org/10.1007/BF00311288
  32. Nagata, K. and Hayashi, M. (2001) Structure relaxation of silicate melts containing iron oxide. J. Non-Cryst. Solids, 282, 1-6. https://doi.org/10.1016/S0022-3093(01)00322-2
  33. Poulsen, S.L., Kocaba, V., Le Saout, G., Jakobsen, H.J., Scrivener, K.L., and Skibsted, J. (2009) Improved quantification of alite and belite in anhydrous Portland cements by $^{29}Si$ MAS NMR: Effects of paramagnetic ions. Solid State Nucl. Mag., 36, 32-44. https://doi.org/10.1016/j.ssnmr.2009.05.001
  34. Rost, S., Garnero, E.J., Williams, Q., and Manga, M. (2005) Seismological constraints on a possible plume root at the core-mantle boundary. Nature, 435, 666-669. https://doi.org/10.1038/nature03620
  35. Slichter, C.P. (1996) Principles of magnetic resonance (3rd Ed.), Springer.
  36. Stebbins, J.F. and Kelsey, K.E. (2009) Anomalous resonances in Si-29 and Al-27 NMR spectra of pyrope ($[Mg,Fe]_{3}Al_{2}Si_{3}O_{12}$) garnets: effects of paramagnetic cations. Phys. Chem. Chem. Phys., 11, 6906-6917. https://doi.org/10.1039/b904731j
  37. Stebbins, J.F., Panero, W.R., Smyth, J.R., and Frost, D.J. (2009) Forsterite, wadsleyite, and ringwoodite ($Mg_{2}SiO_{4}$): Si-29 NMR constraints on structural disorder and effects of paramagnetic impurity ions. Am. Miner., 94, 626-629. https://doi.org/10.2138/am.2009.3140
  38. Sugawara, T. and Akaogi, M. (2004) Calorimetry of liquids in the system $Na_{2}O$-$Fe_{2}O_{3}$-$SiO_{2}$. Am. Miner., 89, 1586-1596. https://doi.org/10.2138/am-2004-11-1202
  39. Tangeman, J.A. and Lange, R.A. (1998) The effect of $Al^{3+}$, $Fe^{3+}$, and $Ti^{4+}$ on the configurational heat capacities of sodium silicate liquids. Phys. Chem. Miner., 26, 83-99. https://doi.org/10.1007/s002690050164
  40. Tse, D. and Hartmann, S.R. (1968) Nuclear spin-lattice relaxation via paramagnetic centers without spin diffusion. Phys. Rev. Lett., 21, 511-514. https://doi.org/10.1103/PhysRevLett.21.511
  41. Wang, Z.F., Cooney, T.F., and Sharma, S.K. (1993) High-temperature structural investigation of $Na_{2}O$․0.5$Fe_{2}O_{3}$․3$SiO_{2}$ and $Na_{2}O$․FeO․3$SiO_{2}$ melts and glasses. Contrib. Mineral. Petr., 115, 112-122. https://doi.org/10.1007/BF00712983
  42. Wilke, M., Farges, F., Partzsch, G.M., Schmidt, C., and Behrens, H. (2007) Speciation of Fe in silicate glasses and melts by in-situ XANES spectroscopy. Am. Miner., 92, 44-56. https://doi.org/10.2138/am.2007.1976
  43. Wilke, M., Farges, F., Petit, P.E., Brown, G.E., and Martin, F. (2001) Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study. Am. Miner., 86, 714-730. https://doi.org/10.2138/am-2001-5-612
  44. Winter, J.D. (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall, New Jersey.
  45. Xue, X.Y., Stebbins, J.F., and Kanzaki, M. (1994) Correlations between O-17 NMR parameters and local-structure around oxygen in high-pressure silicates- implications for the structure of silicate melts at high-pressure. Am. Miner., 79, 31-42.

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