Week+of+7-18+to+7-22

7-18-11 Natalie gave me the week of 7-11 to 7-15 off because she was helping with the nanotech. Sharon and I began scanning a sample of octanethiol on Au(III) that Natalie had prepared. the box to control the voltage of the piezo stack was ready and working when I arrived in the morning. It has more possible voltage than the last system we used. This new system uses 15 9-volt batteries as apposed to the 6 we had before. We tried scanning and got one image before the piezo power supply began fluctuating and we opened up the box and tested all of the batteries with the voltmeter. Inside, there were two batteries that had a voltage unlike any of the others and so we went down to the Physics shop and got two new batteries. The first image we shot the laser at was 7-18-11AD. It was a decent image and the piezo power supply started out at 42.0 Volts before we scanned then after we scanned we brought it down to 2.5 volts. After this, we shot the laser for 30 seconds then let the sample cool for 30 more seconds. We brought the voltage back up to 42.0 volts and scanned it. We saw that it was not the same area as before and figured it moved so we stopped scanning it. However, this new area we found was quite nice and we decided to shoot the laser at it: 7-18-11AE. We retracted the power of the piezo stack from 42.0 Volts to 16.4 Volts then fired the laser for 30 seconds. We let it cool for 30 seconds then we reapproached with the piezo power supply to 42.0 volts and began scanning and got the same area just down a bit. The after image, 7-18-11-AF, showed an increase in size in most of the features. After lunch, I came back and sharon now has her own computer and will be doing her own scanning apart from me now and will no longer be working on the laser with me. I tried changing the tip and scanning but a little while after I tried scanning, a battery exploded in the piezo stack's power supply so I will not be able to use it for a while. Howeever, I did get one decent scan, 7-8-11AH, that I was going to shoot the laser at but I was interrupted by the exploding battery. Before:7-18-11AE media type="custom" key="10200029" After:7-18-11AF media type="custom" key="10200061" Image: 7-18-11AH media type="custom" key="10200095" 7-19-11 Today I scanned octanethiol on Au(III). It was the same sample from yesterday. I came in and the power box for the piezo stack was still not fixed so I was unable to use it to utilize the functionalities of the laser.The STM acted oddly all day and would not approach the way it should. When I finally did get the STM to work, I got a few scans. None of these scans was very good. This could be due to bad tips or the sample. The piezo stack power box was fixed by the end of the day so I will be able to use it and the laser Thursday since I will not be here tomorrow 7-20. I only successfully scanned three areas and these areas were not very good. 7-20-11 Did not go to lab today 7-21-11 I scanned a sample of Octanethiol on Au(III). Overall, the scans today were better than previous days. I did not have as many terrible images as I have on other days but I also did not get that many images that were too spectacular. Most of the images have been pretty noisy but some have had some pretty distinguishable features like in "7-21-11AJ". I was not able to get a good enough image to fire the laser at until after lunch. The first laser try was on image "7-21-11AP" and the after image was"7-21-11AQ". I brought the voltage of the piezo stack from 50.0 V to 20.0 V. I shot the laser for 45 seconds then let it cool for 45 more seconds. It appeared though that the after image had moved a bit to the right because some of the features on the image were still recognizable from the first image, just shifted. However, it is possible and almost more likely that the image moved to a completely different region. The only possibility of a similar area would be if the after image was the top left region of the before image. Image: 7-21-11AJ media type="custom" key="10200123" Before: 7-21-11AP media type="custom" key="10200135" After: 7-21-11AQ media type="custom" key="10200173"

7-22-11 I came in today and Natalie had prepared a new sample of octanethiol on Au(III) for me. I started the day by scanning this sample. I took a couple images then changed the tip. After I changed the tip, I got a good enough image to shoot the laser at: "7-22-11AC". I brought the voltage of the piezo stack from 40.0 V to 10.0 V.Then, I shot the laser for 45 seconds then let it cool for forty five seconds. I put the voltage back to 40.0 V. I think that, in my after image, the scanning region might have moved to a completely different area from the before image. It is unlikely that much will be gained from this set of before and after images because they did not seem to be the same area and it will be hard to analyze any changes. I got another image, "7-22-11AH", that I thought was good enough to scan. I brought the voltage of the piezo stack from 45.0 V to 10.0 V. I shot the laser for 35 seconds then let it cool for 70 seconds. What I found in this trial was not what I hoped for but it was important. I found out that some of the light does go through the gold and affect the tip. I discovered this because after letting the gold for about 70 seconds and bringing the voltage back to its previous amount, the tip still crashed into the gold and I could not scan it. This laser attempt proved unsuccessful also because it appeared to have moved to a completely different region. I got some pretty good scans overall today but my laser trials were mostly unsuccessful. Before: 7-22-11AC media type="custom" key="10200227" After:7-22-11AD media type="custom" key="10200241" Before: 7-22-11AH media type="custom" key="10200255" After: 7-22-11AI media type="custom" key="10200277"