Pressure-induced amorphization of germanium diselenide

Differential thermal analysis of Ag–Ge–Se, Ge–Se charge materials in the process of their heating and Ag8GeSe6, GeSe2 compound synthesis

“…The DTA↓ thermogram of the reaction products in GeSe charge material shows sharp and abrupt peaks 6 and 7, which indicate the crystallization of GeSe 2 compound (peak 6, T 6 = 997 K), and phase transition β-GeSe 2 → α-GeSe 2 (peak 7, T 7 = 840 K). Thus, according to data in [27,28], the phase transition in GeSe 2 compounds must occur in temperature interval (598…698) K, but in our experiment peak 7 begins at a considerably higher temperature of 840 K (Fig. 3b).…”

Direct laser micropatterning of GeSe2 nanostructures film with controlled optoelectrical properties

“…GeSe 2 exists in two crystallographic modifications in normal pressure conditions, low temperature (LT, α-crystalline phase) and high temperature (HT, β-crystalline phase). 31,32 The HT phase has two dimensional layered structure in which GeSe 4/2 tetrahedrons are mutually connected both in corners (corner sharing tetrahedron or CST) and edges (edge sharing tetrahedron or EST) with equal number of CSTs and ESTs. 33 The LT phase has a three dimensional structure consisting of the same GeSe 4 framework but connected only by the CSTs with the tetrahedron chains aligned along directions [001] and [010].…”

Static Structure of Liquid GeSe Under Pressure: Ab Initio Molecular Dynamics Simulations

“…Germanium selenide (Ge x Se 1− x ) compounds attract scientific interest because of their high glass‐forming ability at the Se‐rich concentration, and their applicable semi‐conductivity for electronic devices. In the Se‐rich region, crystal GeSe 2 has three phases, α‐, β‐, and γ‐GeSe 2 .…”

“…After melting, such tetrahedral units remain in the liquid GeSe 2 . For the pressure‐induced structural change, Popovic et al reported that there were several phase transitions at room temperature with increasing pressure up to 12.5 GPa. Those transitions are as follows: from the crystalline β‐GeSe 2 to fully disordered structure at 6.2 GPa, a indication of phase transition from the disordered to two dimensional α‐GeSe 2 at 7 GPa, and amorphization again at 8 GPa.…”