A precise determination of the shape, size and distribution of size of crystallites in zinc oxide by X-ray line-broadening analysis

The Fourier and variance methods are used to analyse the breadths of X-ray diffraction peaks from ZnO powder obtained from the thermal decomposition of Zn₃(OH)₄(NO₃)₂. The shape, size, distribution of size and orientation of the crystallites are determined. It is found that the form is markedly anisotropic and that on average the crystallites may be regarded as cylinders with a diameter of about 110 Å and height about 240 Å, but that they are in fact right prisms whose cross section is an irregular hexagon. There is excellent agreement between the experimental results and the predictions of line-broadening theory, with quantitative confirmation from electron micrographs of the sample.