Preparation of YBa2Cu3O7−δ thin films with thickness gradients and investigations of growth stages by scanning tunneling microscopy

Abstract

The growth of (001) oriented YBa2Cu3O7−δ films on LaAlO3(100) has been studied by scanning tunneling microscopy. Using a special half-shadow technique different growth stages have been obtained simultaneously on a single substrate crystal: nucleation and spreading of two-dimensional islands, their coalescence and growth, formation of well-developed growth hills and finally of a continuous film. The growth steps were determined to be one unit cell spacing in height regarding the crystallographic c-axis.