Application of x-ray phase-contrast imaging to polycrystalline CVD diamond

Surface morphology, individual grains and cracks in free-standing polycrystalline diamond samples have been imaged by a series of x-ray phase-contrast techniques, using well collimated synchrotron radiation of moderate coherence length at a `second-generation' source (Daresbury, UK). Whole samples (10 × 10 mm² and larger) as well as selected regions have been studied. These contained crystallites of diameters in the range 50-200 µm. Contrast control has been achieved by varying the angle of an analysing crystal in the transmitted beam.