An intermediate fcc Zr state observed in the Cu–Zr–Ni system upon ion beam mixing

Abstract

A unique face-centered-cubic (fcc) Zr-based solid solution was obtained in the Cu10Zr76Ni14 multilayered films upon 200keV xenon ion beam mixing, accompanied by a novel phase transition sequence of Cu+Zr+Ni→dual-FCC→FCC→Amorphous while varying the irradiation dose. The energetic stability sequence, elastic stability and phonon behaviors derived from first-principle calculations jointly evidenced the metastability of fcc Zr from different perspectives. The experimental observations and theoretical calculations together justify the existence of an intermediate fcc Zr state under non-equilibrium conditions. Possible formation mechanisms for the metastable crystalline phase were also discussed in terms of the atomic collision theory.