Growth and Stability of MgO/NiO Multilayered Films on Single Crystal NiO(100)

The less than 1% lattice mismatch between MgO and NiO makes them ideal candidates for investigating the growth and stability of multilayered oxide films. Ultra-thin multilayers composed of alternating films of MgO and NiO were deposited onto a stoichiometric NiO(100) single crystal substrate at 250°C by evaporating Mg and Ni in 5×10−7 Torr of O2, respectively. The structure of these multilayers was determined using LEED. Reactivity and chemical composition studies of the MgO/NiO interfaces were carried out using XPS and UPS. The MgO/NiO multilayers grow epitaxially on NiO(100), as evidenced by LEED. XPS and UPS analysis indicates attenuation of the NiO or MgO peaks during growth which is consistent with discrete layering. Chemical analysis also reveals negligible intermixing of the MgO and NiO layers during deposition. Results pertaining to the thermal stability of the multilayers show that UHV annealing above 750°C results in significant diffusion of MgO into the NiO(100) substrate.