Flat epitaxial diamond/Ir(001) interface visualized by high resolution transmission electron microscopy

High resolution transmission electron microscopy (HRTEM) was used to study the interface structure of epitaxial diamond crystallites deposited on Ir(001)/SrTiO3(001). The selected samples did not show any significant surface roughening of the Ir film after the nucleation step. The diamond crystallites formed a flat, sharp, and crystalline interface with the Ir film without any intermediate layer. The epitaxial relationship is diamond (001)[100] parallel to Ir(0 01)[10 0] and the misorientation of the diamond crystallites directly grown on the iridium is smaller than 1degrees. Homogeneous amorphous interlayers often observed in thick samples are attributed to delamination during cool-down induced by the large thermal misfit between diamond and the substrate. The Ir(00 I)/SrTiO3(001) interface proved to be stable in the harsh CVD plasma environment showing an excellent epitaxy without a measurable misorientation. (C) 2002 Elsevier Science B.V. All rights reserved.