Imaging polycrystalline and smoke MgO surfaces with atomic force microscopy: a case study of high resolution image on a polycrystalline oxide

Atomic force microscopy in contact, non-contact and in high resolution modes have been used to image MgO powder samples, obtained at different degree of sintering, starting from Mg(OH)2 decomposition or obtained in form of smoke. From high resolution AFM images of MgO smoke, the lattice periodicity on regular surfaces has been revealed for the first time, under ambient conditions. The high surface perfection of the microcrystals has been further confirmed by HRTEM analysis. To obtain more information on the local structure of the single faces, in terms of type and distribution of the surface active sites, the adsorption of a simple probe molecule (CO) on such surfaces has been investigated by means of FTIR spectroscopy.