Amorphous/crystalline transition of copper at room-temperature

When a glassy alloy Cu60.6Zr29.4Ti10.0 ribbon was immersed in weak acid HF solution at room-temperature, selective complete leaching out of the Zr and Ti elements occurred, resulting in the formation of a self-organized crystalline copper ribbon with grain size of 32 nm, by accelerated self-diffusion of Cu. Since the glassy alloy is formed by spd hybridization bonding, based on a combination of valence electrons (Eg) that exceeds the electrons (Ec) predicted by crystalline metallic bond theory, disappearance of its extra valence electrons, i.e., ΔE (Eg – Ec = 0.24 eV) for copper, due to leach-out of the Zr and Ti elements, facilitates on crystallization of the copper agglomerate.