Nanoscale characterisation of electronic and spintronic nitrides and arsenides

The limits of applicability of the nanoscale spatial resolution analysis techniques of EFTEM, CBED and dark field imaging as applied to ohmic contacts to AlGaN/GaN and Mn distribution within Ga1-xMnxAs epilayers are considered. EFTEM can be limited by acquisition times necessitating the post processing of images to compensate for sample drift. Complementary technique of assessment are required to address problems of peak overlaps in energy loss spectra or signal to noise problems for low elemental concentrations. The use of 002 dark field imaging to appraise Ga1-xMnxAs epilayers is demonstrated.