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Novel pressure‐induced phase transformations in hydrous layered materials
Author(s) -
Johnston Cliff T.,
Wang ShanLi,
Bish David L.,
Dera Przemyslaw,
Agnew Stephen F.,
Kenney John W.
Publication year - 2002
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 - 10.1029/2002gl015402
Subject(s) - gibbsite , raman spectroscopy , stacking , materials science , phase (matter) , phase transition , diffraction , crystal structure , crystallography , mineralogy , geology , composite material , chemistry , optics , condensed matter physics , aluminium , physics , organic chemistry
High‐pressure Raman and X‐ray diffraction data on single crystals of hydrous layer‐structure minerals, dickite and gibbsite, reveal structural phase transitions occurring between 2.0 and 2.5 GPa. In the case of dickite, this is the first documented occurrence of a pressure‐induced phase transformation in a 1:1 phyllosilicate. Above the transition the structure of individual 1:1 layers remains unchanged, whereas the stacking of individual layers and the interlayer topology change significantly. Similar to dickite, single‐crystal Raman spectra of gibbsite show large perturbations in the v (OH) region and suggest that the interlayer OH groups play a critical role in the phase transformation.