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Pretransitional Behavior in Zincblende HgTe under High Pressure and Temperature
Author(s) -
Besson J. M.,
Grima P.,
Gauthier M.,
Itié J. P.,
Mézouar M.,
Häusermann D.,
Hanfland M.
Publication year - 1996
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/pssb.2221980154
Subject(s) - bulk modulus , phase transition , negative thermal expansion , condensed matter physics , thermal expansion , diffraction , softening , cinnabar , chemistry , high pressure , phonon , thermodynamics , synchrotron radiation , materials science , optics , mineralogy , physics , composite material , hematite
The equation of state of mercury telluride, HgTe, has been measured under pressure in its zincblende and cinnabar phases up to 800K, by X‐ray diffraction under synchrotron radiation in a large volume Paris‐Edinburgh cell. The thermal expansion coefficient decreases to zero around 1.1 GPa and then becomes negative up to the first‐order phase transition to the high‐pressure cinnabar phase, around 1.4 GPa. This behavior is related to the increase with temperature of the nonlinearity in the pressure dependence of the bulk modulus. It indicates an overall softening of the phonon branches of zincblende HgTe prior to the phase transition which characterizes a second‐order pretransitional behavior.