Structure and adhesion of Zr/Mo thin-film interface by PVD: A first-principles prediction

Zr/Mo thin film interfaces were fabricated by physical vapor deposition using single crystal Mo substrates. The facet relationship of Zr(0001)//Mo(110) was dominantly observed in XRD patterns, corresponding well to both the Pitsch-Schrader and Burgers ORs of hcp/bcc type interfaces proposed in literatures. First-principles density functional theory calculations were then performed to investigate the resulting interface structure and the relevant energetics. The Pitsch-Schrader OR Zr/Mo interface was predicted with lower interface energy of 0.876 J/m2 and higher work of separation of 3.26 J/m2, but both are fairly close to those of the Burgers OR counterpart. Differential charge density and Bader charge analyses manifested the strong covalent-like metallic bonding nature of the interface. All these results are in favor of the Mo(110) substrate for depositing hcp Zr thin films with strong adhesion.