Abstract
We have investigated sub-monolayer iron deposition on atomically smooth GaN(0001) pseudo-1 x 1 (1 + 1/12) . The iron is deposited at a substrate temperature of 360 degrees C, upon which reflection high energy electron diffraction shows a transformation to a root 3 x root 3-R30 degrees pattern. After cooling to room temperature, the pattern transforms to a 6 x 6, and scanning tunneling microscopy reveals 6 x 6 reconstructed regions decorating the GaN step edges. First-principles theoretical calculations have been carried out for a range of possible structural models, one of the best being a Ga dimer model consisting of 2/9 monolayer of Fe incorporated into 7/ 3 monolayer of Ga in a relaxed but distorted structure. (C) 2014 AIP Publishing LLC.