Cross-sectional High-Resolution Transmission Electron Microscope Study of Heteroepitaxial Diamond Film Grown on Pt Substrate

Heteroepitaxial diamond film grown on Pt(111) was studied by cross-sectional high-resolution transmission electron microscopy (HRTEM). It is found that the interface has a complicated structure including a thick layer of graphite and many small Pt fragments. The epitaxial growth of diamond on Pt substrate is confirmed to be effective with a relationship of diamond{111}//Pt{111} and diamond<110>//Pt<110>. A high-resolution image of the interface between diamond and Pt reveals that diamond particles directly connect with Pt in the absence of an intermediate layer. In some areas, graphite also shows a structural relationship with the Pt substrate and diamond. The graphite(0001) planes tend to be formed parallel to the Pt surface. A high-resolution image of the interface between graphite and diamond shows graphite(0001)//diamond(111) with three diamond(111) planes matching up with two graphite(0001) planes. Some possible heteroepitaxial and nucleation mechanisms are discussed.