Physics
Scientific paper
Nov 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011gecoa..75.6870h&link_type=abstract
Geochimica et Cosmochimica Acta, Volume 75, Issue 22, p. 6870-6881.
Physics
Scientific paper
We have used a direct imaging technique, in situ atomic force microscopy (AFM), to observe the dissolution of the basal biotite surface by oxalic acid over a range of temperatures close to ambient conditions, using a specially designed AFM liquid cell and non-invasive intermittent contact mode of operation. From the 3-dimensional nanometre-resolution data sets, we observe a process characterised by the slow formation of shallow etch pits in the (0 0 1) surface and fast growth of etch pits from the resulting steps, which represent proxies for the {h k 0} surface. Measurements of dissolution rates as a function of temperature allow a determination of an apparent activation energy ( E a,app ) for the process, via mass-loss calculations from image analysis. We obtain a value of E a,app = 49 ± 2 kJ mol -1 , which is consistent with separate calculations based on planar area etch pit growth, and measurements of etch pit perimeters, indicating that this value of E a,app is representative of {h k 0} surface dissolution. The measurement of etch pit perimeters also enables an estimation of apparent activation energy as a function of step density indicating substantially higher apparent activation energy, up to E a,app = 140 kJ mol -1 , on extrapolation towards a pristine surface with no defects. We suggest that this higher value of E a,app represents the slow formation of etch pits into the (0 0 1) surface.
Banwart Steven A.
Haward Simon J.
Leake Jonathan R.
McMaster Terence J.
Ragnarsdóttir Kristín Vala
No associations
LandOfFree
In situ atomic force microscopy measurements of biotite basal plane reactivity in the presence of oxalic acid does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with In situ atomic force microscopy measurements of biotite basal plane reactivity in the presence of oxalic acid, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and In situ atomic force microscopy measurements of biotite basal plane reactivity in the presence of oxalic acid will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-738634