Cluster separation phenomena in liquid Ga-In alloys

Abstract

Different from the previous experimental and simulating methods, ab initio molecular dynamics simulations are performed to investigate the partial structures of liquid Ga, In and Ga-In alloys. In liquid Ga-In alloys, the positions of first peaks in gGaGa(r) and gInIn(r) are close to those of the pure Ga and In, respectively, and the position of first peak in gGaIn(r) is larger than the average value of pure Ga and In, indicating that inhomogeneous atoms are prone to be repulsed and Ga-Ga and In-In clusters are easy to emerge in the system. The most popular 1311 pair bonds existing in liquid pure Ga and In are dominant in liquid alloys, proving that Ga-Ga and In-In clusters coexist in liquid Ga-In alloy. Through the Voronoi analysis, with In increasing, in the Ga100-xInx (30 ≤x≤50 at.%) region, the main coordination number around Ga atoms abruptly decrease from 12 to 10, proving that Ga-Ga and In-In clusters are prone to be separated. These results are different from those obtained from the micro-inhomogeneous model and reveal the mechanism of cluster separation in liquid Ga-In alloy.