Evaluation of recipes for obtaining single terminated perovskite oxide substrates

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. (0 0 1)SrTiO₃ surfaces were prepared with HF or plasma etching and annealing, (0 0 1)LaAlO₃ surfaces were prepared with or without HCl etching and a consecutive annealing at 750-1100 °C, and (1 1 0)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.