Surface chemistry of silicate minerals at the atomic scale

Abstract

Silicate minerals underpin key processes in geochemistry, atmospheric science, and materials technology, yet their atomic-scale surface chemistry remains insufficiently understood. Their intrinsic heterogeneity and electrical insulation have limited experimental characterization, leaving most mechanistic insight to simulations. Here, we extend the capabilities of noncontact atomic force microscopy (ncAFM) in ultrahigh vacuum to achieve atomic and chemical resolution on natural silicates such as muscovite mica,1,2 feldspar microcline3 and wollastonite.4 Our measurements provide direct evidence for processes central to mineral reactivity, such as ion hydration, ice nucleation, and carbonation reactions. They demonstrate that ncAFM affords fundamental insights previously restricted to theory and offer benchmark data to guide and challenge emerging computational models of mineral-gas interactions.