Week+of+10-15-2012

8-15-2012 I came in today, change the tip from what Matt had been working on and began scanning a sample of Gold that had been submersed in Adamantanethiol for 12 hours and Decanethiol for 2 minutes after the first. AM-8135.09 Å, 4 A/D, 300 ms/line. I zoomed in to the lower left corner of this image because it looked the most interesting. I chose to zoom in to that region because it was mostly flat and had a good deal of features in a small region.  AN-2000 Å, 16 A/D, 300 ms/line. I realized about halfway through that the time I had chosen was not suitable for the area I was scanning. I let it finish then scanned it again. This image is somewhat blurry. I was not expecting much to come from this image but the drift moved it away from the drop-off at the top, thereby improving its quality. AO-2000 Å, 16 A/D, 200 ms/line. There was indeed an improvement between the two images here and I believed I had a good enough tip to raise the A/D gain even more to get a better picture. The many collections of lines, especially in the upper right quadrant, are indicative of a monolayer formed from some thiol compound. This is the first real indication of atomic resolution in a very long while. AP-2000Å, 32 A/D, 200 ms/line. This was a much better image. the domain boundaries were much clearer. Unfortunately it drifted near the end. I tried scanning the same region a second time. This image even more clearly shows those lines of molecules visible in the previous image. The pits are formed as a result of the monolayer forming on the surface. AQ- 2000 Å, 32 A/D, 200 ms/line. The same thing happened. I decided just to move the scanning region up. It looks to also have developed a double tip. AR- 2000 Å, 32 A/D, 200 ms/line. The tip gave out once more. I zoomed in to the region on the left side. The double tip unfortunately remained in this image also. AS-1000 Å, 64 A/D, 150 ms/line. The tip died halfway through again. There looked to be atomic resolution. I scanned it again. The strings of brightly colored objects in this image appear to me to be the thiolate molecules. It is one of the clearest images of a monolayer that I have ever gotten and shows fairly clearly what is on the surface. AT- 1000 Å, 64 A/D, 150 ms/line. The tip died about three-fourths of the way through. Matt suggested I take another image then heat it up. Unfortunately, the quality decreased a bit between this and the previous image. The molecules are still fairly clear though AU-1000 Å, 64 A/D, 150 ms/line. I fixed the Y-slope so that I could finally finish the image. AV-1000 Å, 64 A/D, 150 ms/line. I retracted the tip fifteen steps then heated it for 3 seconds. I let it cool for several minutes. The approach took 19 steps. The molecules on this surface are not nearly as clear as the previous few images, indicating that a decrease in the tip's quality occurred. It was either that or the pit on the left edge  AW-8134.5 Å, 32 A/D, 300 ms/line. AX-2000 Å, 32 A/D, 200 ms/line. I moved the scaning region to the left to look for the region from earlier. A general haze unfortunately covers this image. The quality of the tip has definitely decreased since the heating of the sample. However, this is also not of the exact area as before. AY-2000 Å, 32 A/D, 200 ms/line AZ-1000 Å, 64 A/D, 150 ms/line. I retracted the tip 15 steps then heated it for 3 seconds. I let it cool for a couple of minutes then it took 19 steps to approach. This image is much blurrier than those before the heating, possibly because of the expansion of the pit on the left side but also because of the decrease in the quality of the tip.

BA-8135.09 Å, 4 A/D, 300 ms/line. I found the area from earlier. I zoomed in to that region. BB-2000 Å, 32 A/D, 200 ms/line. I found the area quickly from earlier, stopped the scan, and zoomed in to that region. BC-1000 Å, 64 A/D, 150 ms/line. This image does not appear to have increased in quality from before the heating. The molecules are no longer clearly visible in this image, eliminated our ability to really learn much about the surface from the heating, a very unfortunate consequence. BG- 1000 Å, 64 A/D, 150 ms/line 8-16-2012 I came in today and Matt was scanning a sample of overly concentraded Decanethiol. He then informed me that he realized that this was the problem with yesterday's sample, which is why we got such strange-looking molecules. The tip that Matt had been using when I arrived was not the greatest. I cut it and then approached. After it had approached, I was unable to ever scan. The drift was the main problem. It would go crazy every time I tried to scan or adjust the X or Y slopes. I checked the tip and found it to be very loose. I changed it and attempted to approach one more time. The same problem occurred after multiple failed scans. I noticed that the tip was again loose and by that time it was unfortunately time for me to leave. Next week, Matt will prepare a more accurate concentration for the solution so I will most likely be able to get better results.