X-ray photoelectron spectroscopy was used to examine the electronic structure of neodymium gallium perovskite single crystals. They are a pseudo - cubic materials being used as a substrate for epitaxial growth of high temperature superconductors and for group III nitrides (such as GaN). The NdGaO₃ single crystals were grown by the Czochralski method. In order to prepare specimens for XPS analysis, crystals were cut into wafers (0.7 mm thickness), lapped and polished (0.1 m SiO₂). Before the XPS analysis substrates were chemically etched in H₃PO₄ at 65⁰C for 10 min.
The electronic structure measurements of the unpolished, polished and etched (011) wafer planes were performed. For a comparison one wafer was broken perpendicular to the (011) plane, to obtain a fresh surface, without contamination with adsorbed carbon and oxygen. The XPS spectra in the wide energy range 0 - 1400 eV show a presence, for all measured crystals, a contamination with carbon. In the treated crystals a calcium contamination was found. The eatched crystal surface was additionally contaminated with phosphorus. In the broken crystal composition is in agreement with a nominal value. For the other crystals a decrease of the gallium concentration was observed. The Nd, Ga and O line widths change. They are widest for unpolished crystal. The the XPS measurements show that etching with H₃PO₄ did not cause surface damage.
Moreover XPS measurements of the (011) wafer planes annealed in hydrogen atmosphere at 850-1200⁰C were performed. There is a requirement of stability of substrate at the temperature of the growth of epitaxial layers. It was found that during the annealling processes the wafer's surfaces were covered with a white powder. The XPS measurements and chemical composition calculations for the annealed wafers show a vaporising process of Ga.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/815 must be provided.

1. Improvement of the quality of polished SiC wafers using chemical oxidation and heat treatment
2. Comparison of magnetic properties of the monocrystalline and microcrystalline Gd₇Pd₃ compound
3. Comparison of magnetic properties of the monocrystalline and microcrystalline Gd₇Pd₃ compound
4. Electronic structure and magnetic properties of nano and single crystals SrLaAlO₄: Mn
5. XPS characterization of YAlO₃:Co single crystals
6. Magnetic properties of CeNi₄Mn single crystal
7. Preparation of the ZnO substrate surface
8. Crystal and electronic structure of GdPdX (X=Al, Si, Ga, Sn, Ge, In)
9. SPECTROSCOPIC CHARACTERIZATION OF POLYACID MODIFIED RESIN COMPOSITES (PMRC)
10. Characterisation of newly obtained Pb(Mn1/3Nb2/3)O3 ceramics by XRD, XPS and dielectric permittivity tests.
11. Electronic structure of AgNbO₃ single crystals