Metallization in the molten and solid state and phase diagrams of the GeSe2 and GeS2 under high pressure
V. V. Brazhkin, E. Bychkov+, M. V. Kondrin
Vereshchagin Institute of High Pressure Physics of the RAS, 142190 Troitsk, Russia
+LPCA, UMR 8101 CNRS, Universite du Littoral, 59140 Dunkerque, France
We found that under high pressure, the GeSe2 and GeS2 melts pass into
the metallic state.
In the vicinity of the melting curves, their metallization begins at 3.5 and
7 GPa, respectively.
The position of the semiconductor - metal transition line on the phase diagram
for GeSe2 liquid is
established. The GeS2-II and GeSe2-III high-pressure crystalline
semiconductors, whereas the GeSe2-III modification at pressures exceeding
3.5-4 GPa is a metal
The P, T phase diagrams for these compounds are constructed in the
pressure range up to 10 GPa. Metallization during the GeSe2-II-GeSe2-III
transition is evidently
responsible for the small jump of entropy and the corresponding almost vertical
slope of the transition line.