In-situ growth and characterization of epitaxial NI films on MGO substrates

Abstract

Epitaxial metal: insulator interfaces are of growing interest, and their application concerns many different industrial sectors, including thin film growth, electronic and opto-electronic devices. In the present work, Ni was deposited on the (001) MgO surface in an ultra-high vacuum in-situ transmission electron microscope. The films were grown by electron beam evaporation between 25i??C and 600i??C. A novel pseudomorphically strained hcp phase, and an fcc phase was observed in the earliest stages of growth, followed by a structural transformation to an entirely fcc phase of [100] or [110] orientation. In this thesis, we discuss the morphology and the orientations of the fcc phase as a function of film thickness and growth temperature. The activation energy for surface diffusion of Ni on MgO(100) was determined to be ~0.6eV. A novel uniaxial magnetic anisotropy was detected upon in-situ annealing of our films, and the magnetic properties of the film was studied.