All <i>in</i> <i>situ</i> deposition and characterization of YBa2Cu3O7−<i>x</i> thin films by low-energy electron diffraction and low-energy ion scattering spectroscopy

Abstract

In an ultrahigh vacuum apparatus, c-axis oriented YBa2Cu3O7−x (YBCO) thin films were deposited by an ozone-assisted reactive coevaporation method and characterized by low-energy electron diffraction (LEED) and low-energy ion scattering spectroscopy (LEISS). A clean surface with crystal perfection within the top two monolayers was confirmed by LEED for the first time. LEISS analysis showed that this clean surface is terminated by Cu(1)-O chains. These experiments also indicate that the oxygen pressure and the vacuum condition are one of the essential factors in keeping an outermost surface clean.