P. E. Hillner

Tapping mode atomic force microscopy in liquids gives a substantial improvement in imaging quality and stability over standard contact mode. In tapping mode the probe-sample separation is modulated as the probe scans over the sample. This modulation causes the probe to tap on the surface only at the extreme of each modulation cycle and therefore minimizes frictional forces that are present when the probe is constantly in contact with the surface. This imaging mode increases resolution and reduces sample damage on soft samples. For our initial experiments we used a tapping frequency of 17 kHz to image deoxyribonucleic acid plasmids on mica in water. When we imaged the same sample region with the same cantilever, the plasmids appeared 18 nm wide in contact mode and 5 nm in tapping mode.

Research Article| April 01, 1992 Atomic-scale imaging of calcite growth and dissolution in real time P. E. Hillner; P. E. Hillner 1Department of Physics, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar A. J. Gratz; A. J. Gratz 2Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802 Search for other works by this author on: GSW Google Scholar S. Manne; S. Manne 1Department of Physics, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar P. K. Hansma P. K. Hansma 1Department of Physics, University of California, Santa Barbara, California 93106 Search for other works by this author on: GSW Google Scholar Geology (1992) 20 (4): 359–362. https://doi.org/10.1130/0091-7613(1992)020<0359:ASIOCG>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation P. E. Hillner, A. J. Gratz, S. Manne, P. K. Hansma; Atomic-scale imaging of calcite growth and dissolution in real time. Geology 1992;; 20 (4): 359–362. doi: https://doi.org/10.1130/0091-7613(1992)020<0359:ASIOCG>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract We present a new experimental technique for real-time observation of aqueous mineral growth and dissolution at the atomic scale using an atomic-force microscope (AFM) equipped with a flow-through fluid cell. We applied this technique to observe changes in surface topography on the (10 \(\overline{1}\) 4) cleavage plane of calcite during alternating episodes of growth and dissolution. Growth occurred in a layer-by-layer fashion by the forward motion of monomolecular steps (0.3 ±0.1 nm high) lying parallel to the edges of the cleavage face. Under all conditions studied, the velocities of positive [48 \(\overline{1}\) ] and [ \(\overline{4}\) 41] steps were the same; velocities of negative [ \(\overline{4}\) 81] and [ \(\overline{4}\) 41] steps were undetectably small, less than 0.1 not s-1. Steps were straight passing above perfect crystalline material, but roughened into two-dimensional dendrites above defective material. Dissolution nucleated shallow (< 5 nm deep) etch pinholes in defective material and faceted existing surface voids into >90-nm-deep rhombic etch cores. Growth into these etch cores was impeded so that steps moved around them. AFM images of the surface atomic structure revealed rows of atoms along [010] spaced by 0.39 ±0.05 nm with a periodicity along the rows of 0.43 ±0.05 run. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.