Formation of non-equilibrium alloy phases in Cr–Cu multilayered films by ion mixing

Abstract The Cr–Cu system is characterized by its positive heat of formation, which leads to a very limited solid solubility between the constituent metals. By ion irradiation of alternately deposited Cr–Cu multilayered films, however, non-equilibrium amorphous, face-centered-cubic (fcc) crystalline phase and Cr-based supersaturated solid solution were formed at the Cr-rich side. The fcc phase was deduced to contain about 62 at.% of Cr and its lattice constant was determined to be 0.335 nm. The formation of the fcc phase was through a bcc–hcp–fcc transition mechanism from the Cr matrix.