Positron beam characterisation of a CVD-grown diamond thick film

A composite structure consisting of a thick chemical vapour deposition CVD.polycrystalline diamond layer grown on an aluminium substrate, covered with a thin gold cap layer has been studied using positron beam and other techniques. The diamond layer has a strong 110:texture and also contains small fractions of aluminium carbide and graphitic phases. Positron beam analysis reveals two states, corresponding to a highly defective thin gold layer and an homogeneous diamond layer with large, essentially defect free, crystallites. q1999 Elsevier Science B.V. All rights reserved.