Systematic study of the dolomite (104) surface by bimodal dynamic force microscopy in ultra-high vacuum

Abstract

We have investigated the morphology and structure of dolomite MgCa.CO3/2.104/ surfaces by bimodal dynamic force microscopy with flexural and torsional resonance modes in ultra-high vacuum at room temperature. We found that the surface slowly decomposes by degassing CO2 in a vacuum and becomes covered by amorphous clusters, presumably MgO and CaO. By choosing an optimal sample preparation procedure (i.e. cleaving in a vacuum and mild annealing for stabilizing clusters for a short time), atomically clean surfaces were obtained. The complex tip–sample interaction, arising from carbonate groups and Mg and Ca atoms of the surface, induces a large variety of atomic- cale imaging features.