Experimental evidence of the “dead layer” at Pt∕BaTiO3 interface

Abstract

The Pt∕BaTiO3 (BTO) interface was investigated by angle-resolved x-ray photoelectron spectroscopy and x-ray reflectivity technique. It was shown that there exists a transition layer of about 9Å at the Pt/BTO interface with electron density lower than that of the BTO film. The transition layer shows a higher binding energy of Ba 3d than that of the bulk BTO. Moreover, neither the interdiffusion of BTO and Pt nor the oxidation of Pt near the interface had been observed. We consider that this layer is caused by “interface-induced relaxation.” This relaxation layer is believed to be the origin of the “dead layer” effect.