Homoepitaxially grown single crystal CVD diamond has a dislocation arrangement not seen in natural IIa diamond. Whereas in the latter, dislocations lie on (111) planes along [1¯10] directions, dislocations in CVD diamond lie nearly along the [001] growth axis and were arranged in bundles with almost four fold rotational symmetry. Their large strain was easily seen in birefringence and the arrangements in the bundle were modelled so as to account for the singular behaviour of the birefringence when the polarisers were rotated with respect to the crystal. The optical absorption spectrum of brown CVD diamond displays a continuum similar to that found in brown IIa natural diamonds but in addition broad point defect induced bands. The suggestion that the 2.38eV (560 nm) peak was related to VNH was investigated. It was suggested that the breadth of these bands was related to the large structural change when the defect was excited.

Point and Extended Defects in Chemical Vapour Deposited Diamond. H.Pinto, R.Jones, J.P.Goss, P.R.Briddon: Journal of Physics - Conference Series, 2011, 281[1], 012023