Advertisement

Physics and Chemistry of Minerals

, Volume 35, Issue 1, pp 17–23 | Cite as

Plastic deformation of orthoenstatite and the ortho- to high-pressure clinoenstatite transition: a metadynamics simulation study

  • Sandro JahnEmail author
  • Roman Martoňák
Original Paper

Abstract

Atomic-scale mechanisms of plastic deformation in orthoenstatite, MgSiO3 are studied by computer simulation methods. The combined use of metadynamics and molecular dynamics allows a direct observation of the structural changes during the creation of stacking faults in the (100) plane. A sequence of slip deformations in two different (100) planes at = 15 GPa and = 1,000 K reveals a probable transformation mechanism for the ortho- to high-pressure clinopyroxene transition. Each of the observed slips consists of at least four partial deformations crossing high-energy intermediate structures. In agreement with experimental studies, both (100)[010] and (100)[001] slip systems are activated in the deformation process. The observation of a dominant (100)[001] single slip system in pyroxenes may be related to the fact that high-energy intermediate dislocations with (100)[010] component are not stable on geological or experimental timescales.

Keywords

Molecular dynamics Metadynamics Phase transition Enstatite MgSiO3 Orthopyroxene Clinopyroxene 

Notes

Acknowledgments

The authors thank W. Müller, R. Abart, S. Speziale and two reviewers for helpful comments and discussions. R.M. was partially supported by Grant No. VEGA 1/2011/05 and the Centre of Excellence of the Slovak Academy of Sciences (CENG).

References

  1. Aguado A, Bernasconi L, Jahn S, Madden PA (2003) Multipoles and interaction potentials in ionic materials from planewave-DFT calculations. Faraday Discuss 124:171–184CrossRefGoogle Scholar
  2. Ceriani C, Laio A, Fois E, Gamba A, Martoňák R, Parrinello M (2004) Molecular dynamics simulation of reconstructive phase transitions on anhydrous Li-ABW zeolite. Phys Rev B 70:113403CrossRefGoogle Scholar
  3. Coe RS, Kirby SH (1975) The orthoenstatite to clinoenstatite transformation by shearing and reversion by annealing: mechanism and potential applications. Contrib Mineral Petrol 52:29–55CrossRefGoogle Scholar
  4. Coe RS, Müller WF (1973) Crystallographic orientation of clinoenstatite produced by deformation of orthoenstatite. Science 180:64–66CrossRefGoogle Scholar
  5. Hugh-Jones D, Sharp T, Angel R, Woodland A (1996) The transition of orthoferrosilite to high-pressure C2/c clinoferrosilite at ambient temperature. Eur J Mineral 8:1337–1345Google Scholar
  6. Jahn S (2007) High-pressure phase transitions in MgSiO3 orthoenstatite studied by atomistic computer simulation. Am Mineral (submitted)Google Scholar
  7. Jahn S, Madden PA (2007) Modeling Earth materials from crustal to lower mantle conditions: a transferable set of interaction potentials for the CMAS system. Phys Earth Planet Int 162:129–139CrossRefGoogle Scholar
  8. Jahn S, Madden PA, Wilson M (2004) Dynamic simulation of the pressure-driven phase transformations in crystalline Al2O3. Phys Rev B 69:020106 (R)Google Scholar
  9. Kung J, Li B, Uchida T, Wang Y, Neuville D, Liebermann RC (2004) In situ measurements of the sound velocities and densities across the orthopyroxene → high-pressure clinopyroxene transition in MgSiO3 at high pressure. Phys Earth Planet Int 147:27–44CrossRefGoogle Scholar
  10. Madden PA, Heaton R, Aguado A, Jahn S (2006) From first-principles to material properties. J Mol Struct (Theochem) 771:9–18CrossRefGoogle Scholar
  11. Martoňák R, Laio A, Parrinello M (2003) Predicting crystal structures: the Parrinello–Rahman method revisited. Phys Rev Lett 90:075503CrossRefGoogle Scholar
  12. Martoňák R, Laio A, Bernasconi M, Ceriani C, Raiteri P, Zipoli F, Parrinello M (2005) Simulation of structural phase transitions by metadynamics. Z Kristall 220:489–498CrossRefGoogle Scholar
  13. Martoňák R, Donadio D, Oganov A, Parrinello M (2006) Crystal structure transformations in SiO2 from classical and ab initio metadynamics. Nat Mater 5:623–626CrossRefGoogle Scholar
  14. Martoňák R, Donadio D, Oganov AR, Parrinello M (2007a) From 4- to 6- coordinated silica: transformation pathways from metadynamics. Phys Rev B 76:014120CrossRefGoogle Scholar
  15. Martoňák R, Oganov AR, Glass CW (2007b) Crystal structure prediction and simulations of structural transformations: metadynamics and evolutionary algorithms. Phase Transit 80:277–298CrossRefGoogle Scholar
  16. Martyna GJ, Tobias DJ, Klein ML (1994) Constant pressure molecular dynamics algorithms. J Chem Phys 101:4177–4189CrossRefGoogle Scholar
  17. McLaren AC, Etheridge MA (1976) A transmission electron microscopy study of naturally deformed orthopyroxene. I. Slip mechanisms. Contrib Mineral Petrol 57:163–177CrossRefGoogle Scholar
  18. Miyake A, Shimobayashi N, Miura E, Kitamura M (2002) Molecular dynamics simulations of phase transition between high-temperature and high-pressure clinoenstatite. Phys Earth Planet Int 129:1–11CrossRefGoogle Scholar
  19. Oganov AR, Martoňák R, Laio A, Raiteri P, Parrinello M (2005) Anisotropy of Earth’s D” layer and stacking faults in the MgSiO3 post-perovskite phase. Nature 438:1142–1144CrossRefGoogle Scholar
  20. Presnall DC (1995) Phase diagrams of Earth-forming minerals. In: Mineral physics and crystallography, a handbook of physical constants. AGU Reference Shelf, vol 2. American Geophysical Union, Washington, pp 248–268Google Scholar
  21. Sasaki S, Takeuchi Y, Fujino K, Akimoto S (1982) Electron-density distributions of three orthopyroxenes, Mg2Si2O6, Co2Si2O6, and Fe2Si2O6. Z Kristall 156:279–297Google Scholar
  22. Shimobayashi N, Miyake A, Kitamura M, Miura E (2001) Molecular dynamics simulations of the phase transition between low-temperature and high-temperature clinoenstatites. Phys Chem Minerals 28:591–599CrossRefGoogle Scholar
  23. Thompson RM, Downs RT (2003) Model pyroxenes I: ideal pyroxene topologies. Am Mineral 88:653–666Google Scholar
  24. van Duysen JC, Doukhan N, Doukhan JC (1985) Transmission electron microscope study of dislocations in orthopyroxene (Mg,Fe)2Si2O6. Phys Chem Minerals 12:39–44Google Scholar
  25. Weidner DJ, Wang H, Ito J (1978) Elasticity of orthoenstatite. Phys Earth Planet Int 17:P7–P13CrossRefGoogle Scholar
  26. Woodland AB (1998) The orthorhombic to high-P monoclinic phase transition in Mg-Fe pyroxenes: can it produce a seismic discontinuity? Geophys Res Lett 25:1241–1244CrossRefGoogle Scholar
  27. Woodland AB, Angel RJ (1997) Reversal of the orthoferrosilite– high-P clinoferrosilite transition, a phase diagram for FeSiO3 and implications for the mineralogy of the Earth’s upper mantle. Eur J Mineral 9:245–254Google Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department 4GeoForschungsZentrum PotsdamPotsdamGermany
  2. 2.Department of Experimental Physics, Faculty of Mathematics, Physics and InformaticsComenius UniversityBratislavaSlovakia

Personalised recommendations