Week+of+4-24+and+4-25

4-24-12 I came in today and began scanning a sample of Octanethiol on Au(111) that Natalie prepared. The first scan was bumpy and blurry with a Z-range of 200 nm so I stopped it quickly and changed the tip. The next image was better but was also not spectacular. I finished it, "AA", then changed the tip because it was evident that the tip was of low quality. "AB" had a lot of features. I zoomed in to the right half of the bottom left quadrant. The zoomed-in image had lots of streaks and was very blurry. I stopped it and changed the tip. "AC" had an interesting surface. There were many hills as well as valleys. I zoomed in to the middle left of the top half. The next image was blurry as expected. I changed the tip during it. "AD" had an incredible amount of features. However it was also very blurry, probably too blurry to zoom in. I changed the tip after it. 4-24-12AA media type="custom" key="17434746" Although this image has many reasonably good features, the streaks in the bottom fifth of the image indicate a poor tip. This is what I used to decide that I should not continue with this tip 4-24-12AB media type="custom" key="17435084" The region in the upper left quadrant is very clear in showing the quality of the tip. It is grainy and undefined. The features throughout the image have a general haze over them. I zoomed in to a region in the bottom left quadrant that turned out to be even blurrier than this image.

4-24-12AC media type="custom" key="17435456" This image is very interesting. The surface has hills and valleys seemingly on top of each other. There are many streaks in this image. There are not very clear boundaries between any of the regions on this image. 4-24-12AD media type="custom" key="17435620" There are countless features in this image. However, they are undefined and covered by a haze.The boundaries of the rift in the top half show us very clearly that the tip is of poor quality. They are undefined and look very pixelated. 4-25-12 I arrivded today and scanned the same sample of Octanethiol on Au(111) from yesterday. "AA" was fairly blurry. I changed the tip after it. The next scan crashed. As did the one that followed. "AB" was quite foggy. I cut the tip after it. "AC" was less blurry than the previous two images. It had some decent features. I zoomed in to the middle of the right side of "AC". I shot the laser at "AD" for thirty seconds without using the Piezoelectric system or trying to retract it with the computer. I let it cool for 45 seconds then I resumed scanning. It was most assuredly the same area. I wanted to try it again with the same region so I shot the laser again for thirty seconds. It cooled for 45 seconds. The second image was also of the same region. I cut the tip after because I tried moving the region and the scan was horrible. The next scan had many streaks. I changed the tip halfway through it. "AG" had many features. I zoomed in to the top left half of it. The next scan was very blurry. The features were not very visible and there were many streaks so I changed the tip. My last attempt for the day ended with the tip crashing. 4-25-12AA media type="custom" key="17435798" There are many decent features in this image. The surface looks like it is unpolished. There is noise that pervades the entirety of the image. The boundaries in the bottom right quadrant indicate the dullness of the tip. I changed it afterward. 4-25-12AB media type="custom" key="17436062" There are few recognizable features in this image and they are covered very heavily in haze. There is very little definition throughout this entire image.It was very clear that I needed to cut the tip. 4-25-12AC media type="custom" key="17436266" This image has more clearly visible features than the last one. Although it is blurry, this image looks like it is more easily fixed through adjustment of scanning parameters than the last image. I decided to test it and zoomed in to the middle of the right side. 4-25-12AD media type="custom" key="17436522" Although one cannot see the molecules on the surface in this image, the features are fairly decent and I have had a lot of trouble getting images of at least this quality all semester. I decided to shoot the laser at it for 30 seconds. I let it cool for 45 seconds and then took "AE". 4-25-12AE media type="custom" key="17436826" These two images are most definitely of the same region. I have included the previous image here. This is because the hills in the areas which I have circled have disappeared from the before image (below) to the after image (above). This is indeed very interesting and could give us insight into the molecules. media type="custom" key="17437084" I decided to shoot the laser at this image again to see what would happen. 4-25-12AF Before media type="custom" key="17437632" After: media type="custom" key="17438200" I have indicated the areas which have changed from the before image of "AE" to the after of "AF". Two hills were lost and one valley. 4-25-12AG media type="custom" key="17437812" There are many decently defined features in this image. However, one can tell from the streaks in the lower third that the tip is of low quality here. I tried getting a closer image by zooming in but my efforts proved fruitless. I had hoped that, by adjusting the scanning parameters, I would have been able to improve the quality.