Ionization and diffusion of metal atoms under electric field at metal/insulator interfaces; First-principles study

The ionization and diffusion of metal atoms at metal/SiO2 interfaces under an electric field are studied by first-principles calculation. It is shown that the ionization of metal atoms occurs when the hybridization of metal-atom electronic states with metal-induced gap states (MIGS) is broken. Moreover, we show that an electric field markedly decreases the penetration barrier of metal atoms from a metal electrode into SiO2 and enhances the diffusion of metal atoms.