Diamond coatings prepared by microwave plasma-assisted chemical vapour deposition on silicon substrates were studied using high-resolution electron microscopy and extended energy-loss fine-structure spectroscopy. The former observations permitted a wide range of growth defects, based mainly upon coherent twinning on {111} planes, to be identified. It was noted that 5-fold twin centres were very rarely found, whereas the images often revealed extended areas exhibiting the perfect diamond structure. Both observations indicated a film quality that was higher than that usual of synthetic diamonds. A <110> image exhibited various twin and grain boundaries of types Σ = 3, 9, 19, 27, 33 and 81, as well as one 5-fold twin centre, and of an extended perfect structure area viewed along the <111> direction. A particularly interesting defect configuration consisting of three neighbouring dissociated dislocations was also analysed. One of these, a pure extended-screw dislocation, permitted a determination of the intrinsic stacking-fault energy in diamond; yielding a value of 276mJ/m2. This value, although lower than predicted, agreed well with the mean values previously deduced from weak-beam experiments.

HREM and EXELFS Investigation of Local Structure in Thin CVD Diamond Films. D.Dorignac, V.Serin, S.Delclos, F.Phillipp, D.Rats, L.Vandenbulcke: Diamond and Related Materials, 1997, 6[5-7], 758-62