Crystal Structure of MgF2 and FeF2 Under High Pressure

  1. Murli H. Manghnani and
  2. Yasuhiko Syono
  1. N. Nakagiri,
  2. M. H. Manghnani,
  3. Y. H. Kim and
  4. L. C. Ming

Published Online: 21 MAR 2013

DOI: 10.1029/GM039p0281

High-Pressure Research in Mineral Physics: A Volume in Honor of Syun-iti Akimoto

High-Pressure Research in Mineral Physics: A Volume in Honor of Syun-iti Akimoto

How to Cite

Nakagiri, N., Manghnani, M. H., Kim, Y. H. and Ming, L. C. (1987) Crystal Structure of MgF2 and FeF2 Under High Pressure, in High-Pressure Research in Mineral Physics: A Volume in Honor of Syun-iti Akimoto (eds M. H. Manghnani and Y. Syono), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM039p0281

Author Information

  1. Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii, 96822, USA

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780875900667

Online ISBN: 9781118664124

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Keywords:

  • Mineralogy and Crystal Chemistry;
  • Phase transformations;
  • High Pressure-High Temperature Research

Summary

The crystal structure and the unit cell parameters of MgF2 and FeF2 have been studied at room temperature up to a pressure of 4.8 GPa using a diamond-anvil cell and a four-circle X-ray diffractometer. From the pressure-volume data, the isothermal bulk moduli are determined to be 97.1 GPa and 100.0 GPa for MgF2 and FeF2, respectively. The ratio of the cell parameters, c/a, increases with pressure in both MgF2 and FeF2. The positional parameter x decreases with pressure in MgF2, and increases with pressure in FeF2. The distortion of the octahedron has been discussed on the basis of the present experimental results. The pressure dependence of x has been theoretically calculated using the rigid-ion model for the six difluorides MgF2, NiF2, ZnF2, CoF2, FeF2 and MnF2.