A novel method for the determination of grain size distribution and microstrain in nanocrystalline materials from single X-ray diffraction peak

A new method for determining simultaneous grain-size distribution and microstrain from single X-ray diffraction peak is presented. The method combines both the single peak real-space method of Langford and single peak fourier-space method of Nandi et al to determine two apparent size parameters. If the morphology of the grains is known from a separate experiment (viz. TEM) the apparent size value may be used to determine the grain size distribution. In the present work a log-normal distribution of spherical grains was assumed and the median and variance of the distribution was determined for ball-milled vanadium-pentoxide samples. It is proposed that the present method givcs reliable information regarding grain size distribution and microstrain compared to any other single peak methods. The method may be widely applicable to most nanocrystalline materials with only limitation in case of materials exhibiting grain size disparity (viz. bi-modal or multi-modal size distribution) and does not require extensive TEM analysis.