$\alpha -$ to $\beta $- to $\gamma $-spinel transformations in Mg$_{2}$SiO$_{4}$.

ORAL

Abstract

Phase relations in Mg$_{2}$SiO$_{4}$ have been investigated by first principles quasiharmonic calculations. The $\alpha $- to $\beta $-spinel transition is believed to cause the 410-km discontinuity, while the $\beta $- to $\gamma $-spinel transformation may contribute to the 520-km discontinuity. We have obtained these phase boundaries using LDA and PBE/GGA exchange correlation functionals and results confirm the trend usually displayed by these functionals. Information on this series of transformations in Mg$_{2}$SiO$_{4}$ will help us understand the importance of other elements on this sequence of phase transformations across the Earth's transition zone.

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Authors

  • Zhongqing Wu

    Minnesota Supercomputing Institute and Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave SE

  • Yonggang Yu

    Minnesota Supercomputing Institute and Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave SE

  • Renata M. Wentzcovitch

    University of Minnesota, Minnesota Supercomputing Institute, Department od Chemical Engineering and Materials Science, University of Minnesota, Minnesota Supercomputing Institute and Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave SE, Minnesota Supercomputing Institute, Department of Chemical Engineering and Materials Science, University of Minnesota