Skip to main content
SpringerLink
Log in

Structural states of Mg-cordierite II: Landau theory

  • Published:
Physics and Chemistry of Minerals Aims and scope Submit manuscript

Abstract

Mg-cordierite undergoes a ferroelestic phase transitionP6/mmc-Cccm. The order parameterQ is proportional to the spontaneous strain as reflected by changes of the lattice parametersa andb during the phase transition. The order parameter,Q od, which describes the Al, Si ordering, isnot directly involved in the phase transition and only “triggers” the structural collapse.

Landau theory predicts that cordierite can exist in stable or metastable states with hexagonal, orthorhombic or monoclinic symmetry. Hexagonal cordierite can develop modulated structures which have been found by Putnis et al. (1987). The phase transition is predicted to be accompanied by singularities of the elastic constantsC 11,C 22 andC 12 leading to an elastic softening of the crystal structure.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Brody EM, Cummins CW (1986) Brillouin-scattering study of the ferroelastic transition in KH2PO4. Phys Rev Lett 21:1263–1266

    Google Scholar 

  • Carpenter MA, Putnis A, Navrotsky A, McConnell JDC (1983) Enthalpy effects associated with Al, Si ordering in anhydrous Mg cordierite. Geochim Cosmochim Acta 47:899–906

    Google Scholar 

  • Cohen JP, Ross FK, Gibbs GV (1977) An X-ray and neutron diffraction study of hydrous low cordierite. Am Mineral 62:67–78

    Google Scholar 

  • Dénoyer F (1986) In: Incommensurate Phases in Dielectrics 2. Blinc R, Levanyuk AP (ed) Elsevier Science Publishers, Amsterdam Oxford New York

    Google Scholar 

  • Garland CW, Renard R (1966) Order-disorder phenomena. III. Effect of temperature and pressure on the elastic constants of ammonium chloride. J Chem Phys 44:1130–1139

    Google Scholar 

  • Garland CW, Novotny DB (1969) Ultrasonic velocity and attenuation in KH2PO4. Phys Rev 177:971–975

    Google Scholar 

  • Janovec V, Dvorak V, Petzelt J (1975) Symmetry classification and properties of equi-translation structural phase transitions. Czech J Phys B 25:1362–1396

    Google Scholar 

  • Litov E, Uehling EA (1970) Polarization relaxation and susceptibility in the ferroelastic transition region of KD2PO4. Phys Rev B 1:3713–3724

    Google Scholar 

  • McConnell JDC (1985) Symmetry aspects of order-disorder and the application of Landau Theory. Rev Mineral 14:165–186

    Google Scholar 

  • McConnell JDC (1987) personal communication

  • Putnis A (1980) The distortion index in anhydrous Mg-cordierite. Contrib Mineral Petrol 74:135–141

    Google Scholar 

  • Putnis A, Angel RJ (1985) Al, Si ordering in cordierite using magic angle spinning NMR, II: Models of Al, Si order from NMR data. Phys Chem Minerals 12:217–222

    Google Scholar 

  • Putnis A, Salje E, Redfern SAT, Fyfe CA, Strobl H (1987) Structural states of Mg-cordierite I: Order parameters from synchrotron X-ray and NMR data. Phys Chem Minerals 14:446–454

    Google Scholar 

  • Putnis A, Holland TJB (1986) Sector trilling in cordierite and equilibrium overstepping in metamorphism. Contrib Mineral Petrol 93:265–272

    Google Scholar 

  • Rehwald W, Rayl M, Cohen RW, Cody GD (1972) Elastic moduli and magnetic susceptibility of monocrystalline Nb3Sn. Phys Rev B 6:363–371

    Google Scholar 

  • Salje E (1985) Thermodynamics of sodium feldspar I: Order parameter treatment and strain induced coupling effects. Phys Chem Minerals 12:93–98

    Google Scholar 

  • Salje E, Kuscholke B, Wruck B, Kroll H (1985) Thermodynamics of sodium feldspar II: Experimental results and numerical calculations. Phys Chem Minerals 12:99–107

    Google Scholar 

  • Salje E, Devarajan V (1986) Phase transitions in systems with strain-induced coupling between two order parameters. Phase Transitions 6:235–248

    Google Scholar 

  • Schreyer W, Schairer JF (1961) Mg-cordierites: a reinvestigation of the central part of the system MgO-Al2O3-SiO2. J Petrol 2:324–406

    Google Scholar 

  • Testardi LR, Bateman FB (1967) Lattice instability of high-transition-temperature semiconductors. II. Single-crystal V3Si results. Phys Rev 154:402–410

    Google Scholar 

  • Young PW, Scott JF (1986) Brillouin spectroscopy of the incommensurate-commensurate phase transition in barium sodium niobate. Phase Transitions 6:175–234

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Earth Sciences, Downing Street, CB2 3EQ, Cambridge, England

    Ekhard Salje

Authors
  1. Ekhard Salje
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Salje, E. Structural states of Mg-cordierite II: Landau theory. Phys Chem Minerals 14, 455–460 (1987). https://doi.org/10.1007/BF00628823

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00628823

Keywords

Search

Navigation