X-ray diffuse-scattering study of defects in α-sapphire

Strains and defects due to deposition of layered GaN/AlGaN heteroepitaxial structures generated both in α-sapphire substrates and the layers were studied by X-ray high-resolution diffraction and diffuse scattering. Dislocation loops in α-sapphire were identified by calculations of diffuse-scattering intensity in the reciprocal-space maps. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)