TRANSMISSION ELECTRON-MICROSCOPE STUDY OF HETEROEPITAXIAL DIAMOND ON PT(111)

Microstructures of heteroepitaxial diamond films grown on Pt (111) wer e examined by transmission electron microscopy (TEM). Our results show that the film consists of highly (111)-oriented diamond particles inc luding subgrains with azimuthal rotation within similar to-10 degrees. The internal defects such as stacking faults, microtwins and dislocat ions are unevenly distributed within a grain. Electron diffraction pat terns taken in both plan-view and cross-sectional view show that the e pitaxial relationship at some local interface areas between the diamon d and Pt is indeed diamond (111)/Pt (111) and diamond [1 (1) over bar 10]/Pt [1 (1) over bar 0]. However, the interface is very rough, as ni de as similar to 700 nm in depth, including a graphite layer of simila r to 300 nm thick and small Pt fragments. Based on the observed struct ures, the origins of the defects, epitaxial alignment of the diamond c rystals, and nucleation site are discussed. (C) 1997 Elsevier Science S.A.