Calcite reconstruction

Calcite Reconstruction 

The surface of a freshly cleaved calcite crystal in humid air reconstructs on the time scale of minutes to hours. The reconstruction is known to be water driven, but there is still speculation about the structure and composition of the film (1,2,3). This movie shows a 2 µm area scanned at 195µm/s (512x512 pixels, 40 Hz scan rate, 13 seconds per frame) for nearly 5 hours. The movie was taken in AC mode using a 10µm cantilever with a resonance frequency of 3.5 MHz. The movie begins about 1 hour after the crystal is cleaved. 

The reconstruction film gives great phase contrast, indicating that it is different than the bare crystal. There are also interesting fast dynamics going on in the “bubbles” left in the reconstruction film. Besides its fast scanning abilities, this movie nicely illustrates the exceptionally low Z noise floor of Cypher because the initial calcite steps are only about 3Å tall. 

1. T.A. Kendall, S.T. Martin, J Phys Chem A, 111(3), p. 505, (2007) 2. J. Baltrusaitis, V.H. Grassian, Surf. Sci. Lett. 603, L99 (2009) 3. J. Bohr, R.A. Wogelius, P.M. Morris, S.L.S Stipp, Geochim. Cosmochim. Ac. 74, p. 5985 (2010)