PNNL

Abstract

Study of phase seperton at Cr/Si interface. Vacuum evaporation of chromium on Si(100) results in an interfacial nanophase layer followed by a mixed grain region. In this work, the mixed grain region in chromium is nearly transformed into a single-phase region, which resulted in a maximum phase separation between nano ? -A15 phase and bulk ?-bcc chromium. It is achieved by creating a temperature gradient across chromium-silicon interface by using rapid evaporation at a growth rate of ~3 ?m/min at a source-tosubstrate (SS) distance of 2 cm. Separately-grown nanophase chromium films at SS distance of 32 cm show predominant ? -A15 phase. Short-SS-distance rapid evaporation has a potential to produce selective phase separation by combining temperature gradient with the interfacial stress.