MICROTOPOGRAPHIC AND MOLECULAR SCALE OBSERVATIONS OF ZEOLITE SURFACE-STRUCTURES - ATOMIC-FORCE MICROSCOPY ON NATURAL HEULANDITE

Atomic force microscopy (AFM) has been employed to study the surface o f the natural zeolite heulandite. Images on a macroscopic scale exhibi t growth spirals on the outer surface and cleavage tips an the (010) s urface, both with terraces separated from each other by half of the un it cell length b. The angle of the cleavage tips depends on the cleavi ng direction. Molecular resolution is obtained when measured in 0.1 M NaOH, 0.1 and 1 M KOH, and 6.66 M CsOH. The influence of immersion tim e, the nature of the ion species, and the ion concentration on the uni t cell has been investigated. The lattice constants varied around the bulk values.