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Pramana

, Volume 49, Issue 3, pp 285–291 | Cite as

High pressure study of phase transitions inα-FePO4

  • Chitra Murli
  • Surinder M Sharma
  • S K Kulshreshtha
  • S K Sikka
Article

Abstract

High pressure behaviour of FePO4 in berlinite form has been investigated up to 10 GPa using vibrational Raman spectroscopy and energy dispersive x-ray diffraction. Combination of these techniques along with studies on pressure quenched samples reveal structural transitions in this material from its room pressure trigonal phase to a disordered and a crystalline phase near 3±0.5 GPa. The latter is the Cmcm phase which is the equilibrium structure at high pressures. These high pressure phases do not revert back to its initial structure after release of pressure. Irreversibility of these transformations indicates that FeO4 tetrahedra do not regain their initial coordination. These high pressure transitions can be rationalized in terms of the three level free energy diagram for such systems.

Keywords

α-FePO4 phase transition x-ray diffraction Raman scattering 

PACS Nos

62.50 61.50 64.70 

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Copyright information

© Indian Academy of Sciences 1997

Authors and Affiliations

  • Chitra Murli
    • 1
  • Surinder M Sharma
    • 1
  • S K Kulshreshtha
    • 1
    • 2
  • S K Sikka
    • 1
  1. 1.High Pressure Physics DivisionBhabha Atomic Research CentreMumbaiIndia
  2. 2.Chemistry DivisionBhabha Atomic Research CentreMumbaiIndia

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