Preferred orientation and its effect on the ( hk) reflections in X-ray patterns of pyrolytic graphites

Abstract

An expression is developed which describes the effect of the preferred orientation on the shape of ( hk) reflections in bulk-specimen patterns of pyrolytic graphites. This expression suggests a readily applicable correction by which the observed ( hk) reflections are converted to random-powder reflections, i.e. to a form suitable for rigorous analysis based on Warren's theory for random powders. Measurements of the (10) reflection, made with both bulk and random-powder specimens of a pyrolytic graphite, are presented as illustration and test of the ( hk)-shape conversion. The experimental results substantiate the theoretically derived conversion formula.