Synchrotron radiation studies on the growth of TSe 2 (T=Ta, Ti) thin films on Ta substrates: intercalation and de-intercalation of Na

Abstract

In this paper, we study the formation of TSe 2 (T=Ta, Ti)-layered compound thin films, grown on polycrystalline Ta substrates. The experiments were performed in UHV by means of photoemission spectroscopy with synchrotron radiation measurements. The adsorption of elemental Se on Ta substrate at RT produces a film of Se multilayers. With subsequent heating up to 450°C, the deposited Se interacts with Ta, leading to the formation of a TaSe 2 thin film. The simultaneous co-adsorption of Se and TiCl 4 on clean polycrystalline Ta at 250°C produces a TiSe 2 film of ∼5 molecular layers. The production of TiSe 2 film has been confirmed by Na intercalation and following de-intercalation of Na by exposure of the Na/TiSe 2 film to TiCl 4.