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High‐Pressure Structural Study of CuAlS 2 and CuAlSe 2
Author(s) -
Roa L.,
Chervin J. C.,
Itié J. P.,
Polian A.,
Gauthier M.,
Chevy A.
Publication year - 1999
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199901)211:1<455::aid-pssb455>3.0.co;2-o
Subject(s) - chalcopyrite , diffraction , bulk modulus , phase (matter) , x ray crystallography , crystallography , equation of state , materials science , chemistry , thermodynamics , optics , metallurgy , physics , copper , composite material , organic chemistry
The chalcopyrite compounds CuAlS 2 and CuAlSe 2 have been studied by energy dispersive X‐ray diffraction up to 25 GPa. On the upstroke, pressure‐induced first‐order phase transitions from the chalcopyrite structure to a cubic structure, probably of the rock‐salt type, were observed at 14.3 and 12.4 GPa, respectively. It has been impossible to index the diffraction pattern obtained at ambient conditions after a pressure cycle for CuAlS 2 . For CuAlSe 2 only a broadening of the diffraction peaks has been observed after the pressure cycle. The experimental data have shown a decrease under pressure of the structural parameter ε = 2 — c / a . A first‐order Murnaghan equation of state used to fit the experimental PV data in the chalcopyrite phase gives the values of the bulk moduli: (99 ± 3) GPa for CuAls 2 and (85 ± 2) GPa for CuAlSe 2 , both with a fixed B ' = 4.