[en] We analyze the structure and dynamics of semiconducting liquid GeSe using ab initio molecular-dynamics simulations. We show the local order of the liquid to be close to that of the low-temperature crystalline phase. alpha -GeSe. In particular, we show that the Peierls distortion, which defines the a phase and vanishes in the high-temperature beta crystalline phase, reenters GeSe in the melt. Examining the distance histograms allows one to analyze the Ge environment as consisting of a Gese(3) unit and having one Ge-Ge defective bond. Evidence is presented that Peierls distortion is directly responsible for the semiconducting behavior of the melt. The calculated viscosity and electrical conductivity are in agreement with the experiment. An additional neutron-diffraction experiment indicates that this liquid structure is unmodified 200 K above the melting point.
Disciplines :
Physics
Author, co-author :
Raty, Jean-Yves ; Université de Liège - ULiège > Département de physique > Physique de la matière condensée
Godlevsky, V. V.
Gaspard, Jean-Pierre ; Université de Liège - ULiège > Département de physique > Physique de la matière condensée
Bichara, C.
Bionducci, M.
Bellissent, R.
Ceolin, R.
Chelikowsky, J. R.
Ghosez, Philippe ; Université de Liège - ULiège > Département de physique > Physique théorique des matériaux
Language :
English
Title :
Distance correlations and dynamics of liquid GeSe: An ab initio molecular dynamics study
Publication date :
2001
Journal title :
Physical Review. B, Condensed Matter and Materials Physics
ISSN :
1098-0121
eISSN :
1550-235X
Publisher :
American Physical Society, Woodbury, United States - New York