On the calculation of diffracted intensities from SiC crystals undergoing 2H to 6H transformation by the layer displacement mechanism

Abstract

Computer simulation of 2H to 6H transformation by non-random insertion of layer displacement faults in a random space and time sequence has been performed. The model employed by Pandey, Lele & Krishna [Proc. R. Soc. London Ser. A, (1980), 369, 435-477], which is based on the sequential insertion of layer displacement faults, allows faulting of one-third of the total number of layers on completion of the transformation. The results of the simulation show that the transformation gets arrested because of the formation of interfaces by the impingement of independently formed 6H regions and that the fraction of faulted layers which can be inserted is just 0.276. It is shown that these interfaces are such that they do not lead to any broadening of the 6H reflections common with 2H. While this is in agreement with the theoretical predictions of Pandey et al., the diffuse intensity distribution calculated for the arrested state shows significant departures.