Network rigidity in GeSe2 glass at high pressure.
Acoustic measurements using synchrotron radiation have been performed on glassy GeSe2 up to pressures of 9.6 GPa. A minimum observed in the shear-wave velocity, associated anomalous behavior in Poisson's ratio, and discontinuities in elastic moduli at 4 GPa are indicative of a gradual structural transition in the glass. This is attributed to a network rigidity minimum originating from a competition between two densification mechanisms. At pressures up to 3 GPa, a conversion from edge- to corner-sharing tetrahedra results in a more flexible network. This is contrasted by a gradual increase in coordination number with pressure, which leads to an overall stiffening of the glass.
Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA. sytle.antao@anl.gov
Sytle M
SM
Antao
Chris J
CJ
Benmore
Baosheng
B
Li
Liping
L
Wang
Evgeny
E
Bychkov
John B
JB
Parise