Structure of the {001} talc surface as seen by atomic force microscopy: comparison with X-ray and electron diffraction results

Abstract

In this study the surface structure of a centimetre sized crystal of talc from the Trimouns deposit (Ariege, France) was imaged by atomic force microscopy. The direct image shows detailed characteristics of clay tetrahedral surfaces. The unit-cell dimensions obtained 30 using atomic force microscopy (aor = 5.47±0.28 and bor = 9.48±0.28 A) are found to be slightly higher, with an increased uncertainty, than those obtained using X-ray diffraction (aor = 5.288±0.007 and bor = 9.159±0.010 A) and selected-area electron diffraction (aor = 5.32±0.03 and bor = 9.22±0.05 A). Talc has a quasi-ideal surface, clean of strong 34 structural distortion as compared to most of other clay minerals and unlikely surface 35 relaxation. The observation on the obtained image of apparent cell dimension enlargement is 36 then more likely attributed to instrumental artefacts, also responsible for scattered values of unit-cell parameters rather than related to any surface structural features.