Direct imaging of electron transfer and its influence on superconducting pairing at FeSe/SrTiO₃ interface.

ABSTRACT: The exact mechanism responsible for the significant enhancement of the superconducting transition temperature (T_c) of monolayer iron selenide (FeSe) films on SrTiO₃ (STO) over that of bulk FeSe is an open issue. We present the results of a coordinated study of electrical transport, low temperature electron energy-loss spectroscopy (EELS), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) measurements on FeSe/STO films of different thicknesses. HAADF-STEM imaging together with EELS mapping across the FeSe/STO interface shows direct evidence of electrons transferred from STO to the FeSe layer. The transferred electrons were found to accumulate within the first two atomic layers of the FeSe films near the STO substrate. An ad

SUBMITTER: Zhao W 

PROVIDER: S-EPMC5856486 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature