Week+of+4-11+and+4-12

The week before I was on spring break and the week before that, Natalie had appendicitis and advised Guido and I to not come in to the lab. 4-11-12 I came in today and began scanning a sample of Octanethiol on Au(111) that Natalie prepared. After image "AA', I noticed that the LED screen on the piezoelectric box had begun to fade. Rather than checking the voltages of individual battery I decided to change the first one because I have learned from experience that the first one is usually the only one with a low voltage. After I did this, the screen began working properly again and I resumed scanning. Two of the first three attempts after resulted in tip crashes and the other attempt was very blurry. The next one started out decently but ended up being too blurry after adjusting parameters. I changed the tip part of the way through it. The next two scans approached successfully but were quite blurry. The two after these crashed and I restarted the STM. The next scan approached correctly but was very blurry. The same happened with the next scan. I cleaned the sample holder, the wire cutter, the pliers, and the platform with Ethanol. I cut a new tip and the STM worked much better than before but the image I got was very blurry. I cut the tip part of the way through. The STM after that continuously crashed the sample into the tip. I restarted the system. The next scan approached but was very erratic. I cut the tip one fourth of the way through it. The next scan was a large improvement but it was not spectacular. I finished the scan but did not try zooming in on it. 4-11-12AA media type="custom" key="14139930" The features in this image are decently large and somewhat well-defined. However, it is clear from the bottom region that the tip was fairly dull and that a closer image would be very blurry and provide no more insight into the surface. 4-11-12AB media type="custom" key="14140002" This image does not have very many clear features. The boundaries of the regions are not well defined. There is a general blurriness that pervades the entire image. 4-12-12 I came in today and began scanning the sample of Octanethiol on Au(111) from yesterday.The first scan crashed. I cleaned everything and restarted the STM. "AA" had a lot of streaks but also a lot of features. I zoomed in to the bottom middle region to try to gain a better image. "AB" had a pretty blurry but mostly flat surface. I zoomed in to the upper left corner. "AC" was pretty blurry. I changed the tip afterwards. The next scan was not nearly as good as the previous three. I changed the tip halfway through it. The STM would not approach. I restartd the STM and cut the tip. It worked after this. The scan originally looked very promising but turned out fairly poor. I changed the tip 1/2 of the way through it. I zoomed in to the region slightly to the right of the middle of "AD" which was fairly blurry but had many features. After "AE", I changed the tip because it was very blurry. After this, the STM would not approach again for the rest of the day. 4-12-12AA media type="custom" key="14188610" It is clear from the heavy blurriness in this image that the tip is not of high quality. There are lots of features, though they are not very well defined in this scale. There are streaks throughout the entire image, indicating the poor quality of this tip. 4-12-12AB media type="custom" key="14188630" One can more clearly see the features in this image. The hills in this image are numerous and have decently defined boundaries. The haze of the bottom left corner indicates the poor quality of the tip. 4-12-12AC media type="custom" key="14188766" The diagonal pattern that pervades the entire image and the fuzzy boundaries on the different levels and around the features depict a decent but still poor tip. The hills are mostly fuzzy and give no real insight into the Octanethiol on the surface. 4-12-12AD media type="custom" key="14188866" The top right region of this image show us that this image was scanned with a somewhat blunt, not sharp enough tip. The features in this image are numerous and somewhat well-defined. I tried to gain a better look at them by zooming in to the region in the bottom right quadrant. 4-12-12AE media type="custom" key="14188976" The features in this image are not as well-defined as I had hoped. The noise in this image somewhat resembles unorganized Octanethiol molecules but is most likely just a result of the poor tip. There is not much that can be gained from this image since there is not atomic resolution.

I talked to Professor Kandel today and he said that I will most likely be going in a different direction with my research come summertime.