Journal of the Mineralogical Society of Korea (한국광물학회지)

The Mineralogical Society of Korea (한국광물학회)
권호 표지

TEM Investigations of Structures and Phase Transitions in Tridymite

투과전자현미경을 이용한 Tridymite의 구조 및 상전이 연구

  • 김윤중 (한국기초과학지원연구원 중앙분석기기부)
  • Published : 2002.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

A new polymorph of tridymite, an incommensurately modulated phase (IC phase), has been identified. While the symmetry of the IC lattice is same as that of the Ll phase, the geometry of the IC lattice structure is same as the basis of the L3 structure with a different modulation (modulation vector q=0.22 $c*_{H}$;$\lambda$ 37 ). On the other hand, the characteristic curved diffuse diffration observed from the Ll atoms could occur even at room phase suggests that the dynamic disordering of atoms, especially oxygen atoms could occur even at room temperature. The phase transition of Ll to L3 by grinding is gradual but very conspicuous: LllongrightarrowL1+IClongrightarrowIC+L3longrightarrowL3. However, it is revealed that real transition processes of individual grains are directly related to the local stress fields and preexisting microstructures.

지금까지 기재되지 않았던 새로운 tridymite의 동질다형상의 하나로 비조화 변조상("IC상")을 확인하였다. IC상의 격자형은 L1상과 같은 대칭성을 가진 단사정계(Bb)로 분석되나, 기하학적인 격자 구조는 오히려 L3샅의 바탕 구조와 같으며 L3상과는 다른 형태의 변조구조를 갖는다(변조 벡터 q=0.22 $c*_{H}$ ; $\lambda$ 37 ).편, Ll상의 전자 회절도형에서 보여주는 독특한 분산 회절곡선은 원자 특히 산소 원자의 동적 비배열(dynamic disorder)이 상온에서도 일어날 수 있음을 암시해 준다. Tridymite 시료의 분쇄에 의한 Ll상에서 L3상으로의 상전이는 점진적이기는 하나 매우 두드러지게 일어난다: Ll$\longrightarrow$LI+IC$\longrightarrow$IC+L3$\longrightarrow$L3. 그러나, 분쇄에 의한 상전이의 구체적인 과정은 각 입자의 국부적인 응력 상태와 미세구조의 발달 상태와 밀접한 관련이 있음이 이번 연구를 통해 드러났다.

Keywords

References

  1. Ashworth, J.R.(1989) Transmission electron microscopy of coexisting low-tridymite polymorphs, Miner. Mag., 53, 89-97.
  2. Baur, W.H. (1977) Silicon-oxygen bond lengths, bridging angles Si-O-Si and synthetic low tridymite, Acta Cryst., B33, 2615-2619.
  3. Carpenter, M.A. and Wennemer, M. (1985) Characterization of synthetic tridymites by transmission electron microscopy, Am. Miner., 70, 517-528.
  4. Dollase, W.A. (1967) The crystal structure at 220 $^{\circ}C$ of orthorhombic high tridymite from the Steinbach meteorite. Acta Cryst., 23, 617-623.
  5. Dollase, W.A. and Baur, W.H. (1976) The superstructure of meteoritic low tridymite solved by computer simulation, Am. Miner., 61, 971-978.
  6. Graetsch, H. (1994) Structural characteristics of opaline and microcrystalline silica minerals, Reviews in Mineralogy, 29, 209-232.
  7. Graetsch, H. and Florke, O.W. (1991) X-ray powder diffraction patterns and phase relation of tridymite modifications, Zeit. Krist., 195, 31-48.
  8. Heaney, PJ. (1994) Structure and chemistry of the low-pressure silica polymorphs, Reviews in Mineralogy, 29, 1-40.
  9. Hoffmann, W., Kockmeyer, M., Lons, J., and Vach, Chr. (1983) The transformation of monoclinic lowtridymite MC to a phase with an incommensurate superstructure (abstract), Fortschritte der Mineralogie, 61, 96-98.
  10. Hua, G.T., Welberry, T.R., Withers, R.L., and Thompson, J.G. (1988) An electron diffraction and lattice-dynamical study of the diffuse scattering in $\beta$-cristobalite, SiO$_2$, lApp. Cryst., 21, 458-465. https://doi.org/10.1107/S0021889888004637
  11. Kato, K. and Nukui, A. (1976) Die Kristallstruktur des monoclinen Trif-Tridymits (in German), Acta Cryst., B32, 2486-2491.
  12. Kihara, K. (1977) An orthorhombic superstructure of tridymite existing between about 105 and 180$^{\circ}C$, Zeit. Krist., 146, 185-203.
  13. Kihara, K. (1978) Thermal change in unit-cell dimensions, and a hexagonal structure of tridymite, Zeit. Krist., 148, 237-253.
  14. Kihara, K. (1995) Disorder and successive transitions in the tridymite forms of SiO$_2$, Phys. Chem. Minerals, 22, 223-232.
  15. Kihara, K., Matsumoto, T., and Imamura, M. (1986) Structural change of orthorhombic-l tridymite with temperature: A study based on second-order thermal-vibrational parameters, Zeit. Krist., 177, 27-38.
  16. Kim, Y.J., Nettleship, I., and Kriven, W.M. (1992) Phase transformations in dicalcium silicate. II. TEM studies of crystallography, microstructures and mechanisms, J. Am. Ceram. Soc,, 75, 2407-2419.
  17. Konnert, J. and Appleman, D.E. (1978) The crystal structure of low tridymite, Acta Cryst., B34, 391403.
  18. Nukui, A., Nakazawa, H., and Akao, M. (1978) Thermal changes in monoclinic tridymite, Am. Miner., 63, 1252-1259.
  19. Lons, J. and Hoffmann, W. (1987) Zur Kristallstruktur der inkommensurablen Raum-temperaturphase des Tridymites (in German, abstract), Zeit Krist., 178, 141-143.
  20. Phillips, B.L., Thompson, lG., Xiao, Y., and Kirkpatrick, RJ. (1993) Constraints on the structure and dynamic of the cristobalite phase of SiO$_2$ and AlPO$_4$ from $^31$p, $^27$Al and $^29$Si NMR spectroscopy up to 800K, Phys, Chem. Minerals, 20, 341-352.
  21. Pryde, A.K.A. and Heine, V. (1998) Analysis of the incomrnensurately modulated OS phase of SiO$_2$ tridymite, Phys, Chem. Minerals, 25, 603-610.
  22. Reid, A.M., William, RJ., and Takeda, H. (1974) Coexiting bronzite and clinobronzite and the thermal evolution of Steinbach meteorite, Earth and Planetary Science Letters, 22, 67-74.
  23. Smelik, E.A. and Reeder, R.R. (1990) A study of the thermal behavior of terrestrial tridymite by continuous X-ray diffraction, Phys. Chem. Minerals, 17, 197-206.
  24. Spearing, D.R., Farnan, 1., and Stebbins, J.F. (1992) Dynamics of the $\alpha$-$\beta$ phase transitions in quartz and cristobalite as observed by in situ hightemperature $^29$Si and $^17$O NMR, Phys, Chem. Minerals, 17, 307-321.
  25. Wennemer, M. and Thompson, A.B. (1984) Tridymite polymorphs and polytypes, Schweizerische Mineralogisch und Petrographaphische Mitteilungen, 64, 335-353.
  26. Withers, R.L., Thompson, J.B., Xiao, Y., and Kirkpatrick, R.J. (1994) An electron diffraction study of the polymorphs of $SiO_2$-tridymite, Phys. Chem. Minerals, 21, 421-433. https://doi.org/10.1007/BF00202272
  27. Xiao, Y., Kirkpatrick, RJ., and Kim, YJ. (1993) Structural phase transitions of tridyrnite: A $^29$Si MAS NMR investigation, Am. Miner., 78, 241-244.
  28. Xiao, Y., Kirpatrick, R.J., and Kim, Y.J. (1995) Investigations of MX-1 tridymite by $^{29}$Si MAS NMR, Phys, Chem. Minerals, 22, 30-40.