Effect of preparation on the growth mode and structure in laser MBE grown multilayer of SrTiO 3 and YBa 2 Cu 3 O y

Abstract

Multilayer of SrTiO 3 (STO)-YBa 2 Cu 3 O 7-δ (YBCO) was fabricated by laser molecular beam epitaxy (LMBE). The properties of multilayer in terms of growth modes, strain and interface structures were characterized by the in situ reflective high energy electron diffraction (RHEED) pattern, and ex situ measurements, such as atomic force microscope (AFM). By controlling growth and processing conditions, we observed a change of different growth modes of thin films. Furthermore, we also demonstrate a strong dependence of growth modes in YBCO films on the growth fashion of STO films, which could be explained in terms of the stress effect at the interface. The dependence of interface stress on thickness and growth condition was determined with AFM. These results provide an understanding and manipulating growth mechanism of the films.