Premium
Garnet‐perovskite transformation in CaGeO 3 : In‐situ X‐ray measurements using synchrotron radiation
Author(s) -
Susaki J.,
Akaogi M.,
Akimoto S.,
Shimomura O.
Publication year - 1985
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl012i010p00729
Subject(s) - synchrotron radiation , perovskite (structure) , enthalpy , materials science , diffraction , phase (matter) , phase boundary , analytical chemistry (journal) , synchrotron , transformation (genetics) , phase transition , mineralogy , thermodynamics , crystallography , geology , chemistry , optics , physics , organic chemistry , chromatography , biochemistry , gene
The garnet‐perovskite phase transformation in CaGeO 3 was investigated in the pressure‐temperature region to 6.5 GPa and 1200°C using a cubic anvil type of high‐pressure apparatus combined with synchrotron radiation. In‐situ measurements with an energy dispersive x‐ray diffraction system enable us to carry out dynamical observation of the transformation. The equilibrium phase boundary between the garnet and perovskite phases was determined as P(GPa)= 6.9 ‐ 0.0008T(°C). The negative P‐T slope definitely established in the present study is in reasonable agreement with the value, −0.0023(8) GPa/°C, that was calculated from the thermochemical data on the enthalpy of transition. The molar volume change accompanied with this transformation was estimated to be about 13% at about 6 GPa and 1000°C.