Surface reactivity enhancement on a Pd/Bi 2 Te 3 heterostructure through robust topological surface states

Abstract

We present a study of the surface reactivity of a Pd/Bi 2 Te 3 thin film heterostructure. The topological surface states from Bi 2 Te 3, being delocalized and robust owing to their topological natures, were found to act as an effective electron bath that significantly enhances the surface reactivity of palladium in the presence of two oxidizing agents, oxygen and tellurium respectively, which is consistent with a theoretical calculation. The surface reactivity of the adsorbed tellurium on this heterostructure is also intensified possibly benefitted from the effective transfer of the bath electrons. A partially inserted iron ferromagnetic layer at the interface of this heterostructure was found to play two competing roles arising from the higher-lying d-band center of the Pd/Fe bilayer and the interaction between the ferromagnetism and the surface spin texture of Bi 2 Te 3 on the surface reactivity and their characteristics also demonstrate that the electron bath effect is long-lasting against accumulated thickness of adsorbates.