Evaluation of recipes for obtaining single terminated perovskite oxide substrates

Abstract

We have re-assessed different methods to obtain single terminated perovskite oxide substrate surfaces of SrTiO3, LaAlO3 and NdGaO3. The surfaces have been probed by a combination of atomic and lateral force microscopy, X-ray photoelectron spectroscopy and reflection high-energy electron diffraction. (001)SrTiO3 surfaces were prepared with HF or plasma etching and annealing, (001)LaAlO3 surfaces were prepared with or without HCl etching and a consecutive annealing at 750–1100°C, and (110)NdGaO3 surfaces were only annealed. Two of the recipes have previously been suggested to result in A-site terminated surfaces. However, except for the case of high-temperature annealed LaAlO3 where we observe a double-terminated surface, our data suggest that the single terminated surfaces obtained by these methods were of B-site type.