Formation and properties of Cr–Si sputtered alloys

Abstract

Cr–Si metastable alloys were prepared by RF sputtering in a low-pressure argon gas. The structure of sputtered alloys results in Cr (Si) solid solution, Cr+Cr 3Si, the amorphous phase with increasing Si content for Cr–Si alloys. The dissolution hardening effect of Si increases the microhardness of Cr(Si) solid solution. The microhardness of Cr–Si sputtered alloys yields the peak around 50 at% Si, and furthermore, the microhardness of Cr–Si alloy, with Si rich content of 80 at% or more increases with Si content. These results suggest that the bonding character of Cr–Si amorphous alloys is different from the metallic-to-covalent bonding of Si-rich alloys. This bonding character difference for Cr–Si rich alloys is also seen in the Si content dependence of the crystallization temperatures for Cr–Si alloys.