Abstract
Using ab initio molecular dynamics simulations, we provide direct evidence for the existence of a first-order liquid–liquid phase transition (LLPT) in AsS melt, with a negative Clapeyron slope of the transition line and a critical point around (1323K<Tc<1423K, 0.06GPa<Pc<0.16GPa). Our predicted transition line is in good agreement with the boundary between high density liquid (HDL) and low density liquid (LDL) suggested in experiment, especially the location of the HDL–LDL–Crystal triple point. Our results show that this first-order LLPT primarily originates from the change of intermediate-range order, i.e., the fourth coordination shell at 4.7Å and the fifth at 6.7Å around a S atom in LDL merge into one at 5.4Å in HDL. Based on our results, a negative thermal expansion coefficient in LDL is predicted. With increasing pressure, the number of 2-fold S-coordinated As atoms decreases in HDL, while that of 3-fold S-coordinated As atoms increases. The total electronic density of states has a deep dip at EF in LDL, which becomes more shallow in HDL.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
