Early stages of growth of epitactic barium bismuth oxide films on single-crystal MgO

Abstract

The growth of barium bismuth oxide thin films on MgO has been examined using Rutherford backscattering spectrometry (RBS), reflection high energy electron diffraction (RHEED) and transmission electron microscopy (TEM). The early stages of growth have been observed by depositing very thin films directly onto specially prepared electron transparent samples. These samples can be transferred directly from the deposition chamber into the electron microscope without the need for post-deposition thinning. The films were found to form by the nucleation and coalescence of individual islands after an initial uniform coverage. Most of the islands were epitactic with the substrate as evidenced by analysis of selected-area diffraction patterns. The composition of the initial phase formed was determined, by Rutherford backscattering spectrometry, to be BaBi 2O y.