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High‐pressure Raman spectroscopy study of α and γ polymorphs of AlH 3
Author(s) -
Tkacz Marek,
Palasyuk Taras,
Graetz Jason,
Saxena Surendra
Publication year - 2008
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1936
Subject(s) - monoclinic crystal system , raman spectroscopy , chemistry , diamond anvil cell , polymorphism (computer science) , crystallography , high pressure , phase transition , ambient pressure , hexagonal crystal system , spectroscopy , analytical chemistry (journal) , crystal structure , thermodynamics , optics , biochemistry , physics , chromatography , quantum mechanics , gene , genotype
For the first time, Raman spectroscopy of α and γ polymorphs of AlH 3 has been performed in the pressure range from ambient up to 16.9 and 32.7 GPa, respectively using the diamond anvil cell (DAC) technique. An analysis of pressure response wavenumbers (ν) for α‐AlH 3 showed a change of dν i /d P at a pressure of about 8 GPa and may indicate a monoclinic distortion from the initially hexagonal α‐AlH 3 . The distortion is stable at least up to 16.9 GPa. The γ form exhibited more complex behavior transforming to the α form at a pressure of about 12 GPa. The structural phase transition was shown to be an irreversible and kinetically slow process that required at least 5 h to complete. Copyright © 2008 John Wiley & Sons, Ltd.