Y_{3}Al_{5}O_{12} (YAG) single crystals doped with vanadium ions (V^{3+}) were obtained by the Czochralski method. The X-ray photoelectron spectra of YAG:V annealed in reducing atmospheres: H_{2}, vacuum and H_{2} + vacuum are presented and compared with the spectra of the YAG ceramics. The X-ray photoelectron spectra showed that the vanadium dopant concentration in YAG:V crystals is lower than a nominal one. For the "as grown" YAG:2.8at.%V crystal vanadium exists in the mixed valence state. The increase in lattice parameters for the samples annealed in hydrogen was found.
X-ray reflectometric and diffraction topographic methods were applied for examination of 4H and 6H silicon carbide substrates finished with various regimes, as well as, silicon carbide epitaxial layers. The investigations indicated a very good quality of the substrate surfaces finished with the process established at the Institute of Electronic Materials Technology, which provided the surface roughness σ = 0.55 ± 0.07 nm for 4H-SiC wafers. These values were better than those of substrate wafers offered by many commercial producers. The surface roughness was decreased during the initial high temperature etching to σ = 0.22 ± 0.07 nm. A relatively good structural quality was confirmed in the case of 4H epitaxial wafers deposited on the substrates prepared from the crystals manufactured at the IEMT, with the 8° off-cut from the main (001) plane.
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