Structural and defect characterization of Gd-doped GaN films by X-ray diffraction and positron annihilation

Abstract

Abstract. Molecular-beam-epitaxy-grown Ga 1−x Gd x N films were investigated by Xray diffraction and slow positron beams. From the positron lifetime results, N-vacancyrelated defects may be expected in the Ga 0.9 Gd 0.1 N film grown under Ga-rich conditions which exhibits a lattice expansion in the c-axis direction. In contrast, Ga vacancies more than 10 19 cm −3 were detected in the Ga 0.9 Gd 0.1 N film grown under N-rich conditions which does not exhibit the lattice expansion, implying that the highly-concentrated Ga vacancies contribute to a relaxation of the lattice distortion caused by incorporating oversized Gd atoms.

Indexing PXRD Structural Parameters of Graphene Oxide-Doped Metal-Organic Frameworks

“…The structural relaxation of the lattice was driven by the substitution of GO layers into the framework. The same distortion of lattices was also figured out by Yabuuchi et al (2014) when doping over-sized gadolinium into gallium nitride films [14]. The calculated parameters of c/a ratio, unit cell volume and Scherrer's crystallite size show that there is no significant influence of GO loading on those physical properties in the range of 0.1-0.6 wt%.…”