Comparison of Sizes of Magnesia Crystals Calculated from X‐ray Diffraction Line‐Broadening and Transmission Electron Microscopy Observations

Abstract

When MgO is formed by decomposition of MgCO3 under vacuum, crystal sizes calculated from XRD line breadths are in reasonable agreement with direct TEM observations, 4.4 ± 0.6 nm compared with 3.2 ± 0.8 nm. For aligned MgO crystallites from Mg(OH)2, the sizes calculated are discordant, 14.0 ± 3.0 nm and 2.6 ± 0.7 nm. The sizes calculated from XRD data are too large because the MgO crystallites form from Mg(OH)2 in near‐perfect alignment.