X-ray Spikes and Metal Inclusions in Synthetic Diamond

Abstract

Meyer and Milledge¹ and Lonsdale and Milledge² reported the presence of anomalous X-ray spikes projecting from the reciprocal lattice points of synthetic diamonds which had been doped with aluminium, boron or nitrogen. These spikes were found to differ from those which have been observed in some natural type I diamonds, in that they lay in 〈111〉 directions instead of 〈100〉 directions, and it was suggested by Lonsdale and Milledge² that the doped synthetic diamonds should show platelets parallel to {111} planes. Recently, Phaal and Zuidema³ found that most synthetic diamonds contain a high density of planar faults lying on {111} planes. It is suggested that the X-ray spikes lying in 〈111〉 directions could be explained by the presence of faults of the type reported by Phaal and Zuidema.