Insight into the effect of reorganized chemical short-range orders at Ga-based alloys/Cu interfaces on the nucleation and growth of CuGa2 crystals

Abstract The present work verified that the presence of pristine chemical short-range orders (CSROs) in both pure Ga and Ga-based alloys at 180 ℃ has no significant influence on the microstructure evolution of bricks-like CuGa2. Due to its low mixed enthalpy of Cu-Ga atomic pairs that facilitates some preferential self-assembled inter- atomic neighborhoods, the diffused Cu atoms destroyed the primitive CRSOs in liquid alloys and thus promoted the reorganization of broken or dissolved pristine CRSOs, which determined the nucleation and growth of CuGa2. The estimated electrical resistivity of CuGa2 is 171.4 times that of pure Cu, indicating that the chemical reaction between Cu and Ga atoms may cause the electrical properties degradation. This study may contribute to design and fabricate soft and wearable electronics with high performance in which low melting point Ga-based alloys are employed.