Effects of spin orbital coupling on atomic and electronic structures in Al_2Cu and Al_2Au crystal and liquid phases via ab initio molecular dynamics simulations

摘要

The origin of different melting points between Al_2Cu and Al_2Au has been studied using ab initio molecular dynamics simulations. Cohesive energy, electronic structures and structure information of both crystal and liquid phases have been analyzed. It is found that spin orbital coupling (SOC) plays an important role on the cohesive energy of crystal phase, consistent with the different melting points of these two alloys. Whereas, it seems that SOC has no effect on the formation energy and structure of liquid phase. Possible mechanism of reduced SOC effect at liquid phase is proposed. Our results are helpful to understand the glass formation ability difference between Al_2Cu and Al_2Au.