Structure-diffraction Analysis of Nanometer-Sized Polycrystals

The results of investigations of X-ray and electron diffraction in polycrystalline zirconia and boron nitride with nanometer-sized crystallites having different interface types are presented. The lattices of zirconia crystallites are conjugated by contact strain-distorted interfaces. Boron nitride consists of crystallites having extended interfaces without long-range order. Disorder is the consequence of decreasing internal strain during polygonization of peripheral crystallite regions. However, in spite of various distortions in periodicity, materials under study have similar selected area (∼0.8 μm) electron diffraction patterns. The integrated diffraction pattern (X-ray diffraction) from an ensemble of uniformly oriented crystallites having both types of interfaces can be simulated as a superposition of reflections from the atoms located at the lattice sites and from amorphous interfaces. The structure-diffraction features of nanometer-sized materials have been deduced from these results.