Growth of dual-phase high entropy alloy films using thermal vapor deposition

Abstract

In this work, physical vapor deposition was used to grow dual-phase high entropy alloy films. The near equiatomic films of CoCrFeMnNi were grown on a freshly cleaved (100) surface of a NaCl substrate. The deposition was carried out at a substrate temperature ranging from −143 °C to 600 °C. The films grown at cryogenic temperatures were completely amorphous while dual- phase microstructure was observed in films grown at room temperature and above. The dual phase consisted of an amorphous and a crystalline domain when grown at room temperature. However, for growth temperatures of 200 °C and above the dual-phase microstructure consisted of compositionally equivalent fcc and hcp phases. In a narrow temperate range of 400–450 °C a partial epitaxy appeared, suggesting the possibility of growing crystallographically oriented films of the high entropy alloys under more refined growth conditions.