Growth of SrCuO2 Thin Films on Oxygen-Annealed SrTiO3 (100) Substrates

Abstract
The effect of annealing on the surface of SrTiO3 (100) substrates and initial growth of SrCuO2 thin films on the SrTiO3 were studied by reflection high-energy electron diffraction (RHEED) and atomic force microscopy (AFM). The terraces of SrTiO3 (100) substrates annealed at 1000° C in O2 atmosphere has atomically flat surfaces with high crystallinity and steps one unit cell high (3.9 Å) . The deposition of SrCuO2 on the annealed substrates forms islands near the steps with a height of 4–7 Å resulting in surface roughening in spite of the flat substrate surface. By depositing Sr as a buffer layer on the annealed substrates, the flatness of SrCuO2 thin films was improved.