Week+of+3-5+and+3-6

3-5-12 I came in today and began scanning a sample of octanethiol on Au(111) that Natalie prepared. Guido is not here today and is not coming in this week so I may use his sample, depending on how mine turns out. The first two scans were blurry. I decided that after my third attempt, I would turn off the Piezoelectric stack and see how this would affect the results. The third scan was also horrible. I turned the piezo stack off. The quality of the next scan improved drastically. I zoomed in to the bottom middle of "AA". This scan was quite poor though. I stopped it 40% of the way through and changed the tip. The next scan was not very good. I cut the tip and scanned again. The following scan had a large amount of features. However, it had a large amount of streaks also but I wanted to see what I could get with the bottom right quadrant. This next scan was quite blurry. I changed the tip halfway through. "AC"'s top half was blurry. It's bottom fourth was also fairly blurry. I wanted to check out the middle of the scan though. I zoomed in here and this scan was also very blurry and undefined. I changed the tip halfway through it. The next scan had a large amount of features. It was fairly blurry though. I zoomed into the left middle region of "AD". It ended up very blurry and I changed the tip halfway through. The next scan also had a pretty poor tip. I cut it after I adjusted the parameters to no avail. The next scan was a large improvement.There was a ridiculous amount of features on it. I zoomed in to the left middle of "AE". The zoomed in scan was unfortunately very blurry. I did not end up finishing the scan because it had very little definition. 3-5-12AA media type="custom" key="12886106" This image has a good amount of decently defined features. However, there is a slight general haze that does indeed cover the whole of the image, preventing us from seeing clearly into the nature of the surface. 3-5-12AB media type="custom" key="12886140" This image dropped drastically in quality near the end as evidenced by the nonsense in the top 15% of the image. Because of this, the tip decreased in quality (although it was not very high to begin with) and this decreased the quality of the zoomed in image. The streaks in the darker valley in the upper left quadrant show that the tip was not of high quality to begin with.

3-5-12AC media type="custom" key="12886130" The streaks in the upper left quadrant should have alerted me of the nature of the tip, which was fairly poor and blunt. The features in this image are decently defined but there is no atomic resolution in this image, which gives us no insight into the Octanethiol molecules on the surface.

3-5-12AD media type="custom" key="12886118" This image is poorly defined because of the scanning parameters used and the low quality tip. The streaks in the bottom middle let me know that the tip is of low quality and I should have changed the tip before zooming in to conserve time. 3-5-12AE media type="custom" key="12886112" This image has an incredibly large amount of features, particularly hills. It looks as though there are even more here then there were on the image I got last week, which I believe to have been the most concentrated image I had ever taken. However, the lack of quality in the tip dwarfs the importance of this vast expanse of features because I was not able to gain more insights into the nature of the surface and the Octanethiol molecules.

3-6-12 I came in today and began scanning the same sample of Octanethiol on Au(111) from yesterday. I started scanning with 30.0 V charged to the piezoelectric stack. The sample would not approach so I turned the STM off and on. It still would not approach so I cleaned the apparatus and it continued to not approach. I crashed the sample on purpose then brought it back and approached quickly. This worked but the quality of the scan was very poor. I changed the tip and it would not work again. Also, after moving the sample back to change the tip, I noticed that one of the wires connecting to the Piezoelectric stack was no longer connected. I tried fixing this but it was welded with some metal that was not lead. I just told Natalie about it. The scan I got after this was not good but it was better than nothing. I think the sample is possibly contributing to the problem -- it is probably damaged. I changed the tip after that image, "AA". The next image was a huge improvement in terms of features but it was still fairly blurry. I finished it then changed the tip. The scan after that was of incredibly low quality and I stopped it about 1/4 of the way through. 3-6-12AA media type="custom" key="12886224" This image is very blurry. It has no recognizable features and is mostly incomprehensible. It provides no insight into the surface of the gold or into the molecules of Octanethiol. 3-6-12AB media type="custom" key="12886228" This image is very fuzzy as shown by the streaks lining the right ridge of the general, visible area. The features are not well-defined but are indeed numerous.

I went to Brian Greene's lecture and learned a lot about inflationary cosmology and the multi-verse theory. It was a very interesting lecture and Dr. Greene did a fantastic job. 3-8-12 I attended the Masterclass on this morning. Overall, it was a very good experience. After going over our events and generating histograms we began the video conference. It was a very cool experience to talk with students from other nations and with the directors at CERN. I learned more about particle physics and more about how people live their daily lives at CERN.