Week+of+7-25+to+7-29

7-25-11 I began the day scanning clean gold because Natalie was preparing a sample of Octanethiol on Au(III) that was not ready for until after lunch. I was unable to get any good scans of the clean gold. I went to lunch and came back and started scanning Natalies new sample. I only managed to get two images of this sample but both were pretty good images. I tried to set up a laser trial on the first image I got but after I had applied the laser, I found that the region had completely moved and wasn't scanning correctly, so I backed up the sample holder then re approached and began scanning again. I was unable to get any images after the first two: "AI" and "AJ". This could be due to either bad tips or the STM not working properly. Image: 7-25-11AI media type="custom" key="10200459" Image: 7-25-11AJ media type="custom" key="10200513"

7-26-11 I began the day by scanning Natalie's sample of Octanethiol on Au(III) from yesterday. I took several images and found one that was pretty good: "7-26-11AE". I brought the voltage of the piezo stack from 45.0 V to 10.0 V on the piezo power supply. I then shot the laser for 35 seconds and let the sample cool for 70 seconds. The laser was not directly on the gold at the beginning so I let it run for a few seconds more than 35 seconds. I was able to reapproach with the extension of the piezo stack and scanned an area that seemed similar to the before image. I think that the scanning region had moved to an entirely different place because it doesn't seem to have any of the same features. I decided to take two images of the after image to see if anything might change after a short time.All that happened was a slight shift to the right. I tested the new tips made by the etching technique. These new tips are extremely sharp and have given me much higher quality images than ever before. However, as Annette pointed out to me, the sample is not as orderly as it should be. The sample I used with these new tips is the new Octanethiol on Au(III) sample that Natalie prepared for me this morning. Natalie and Annette looked over one of the images I got and decided it would be better to leave the sample in solution overnight instead of leaving it for only 3 hours like we have for the past two days to let the solution become more orderly on the gold's surface. Before: 7-26-11AE media type="custom" key="10200539" After: media type="custom" key="10200555" Tip #5: 7-26-11AJ media type="custom" key="10200567" 7-26-11AK media type="custom" key="10200581" 7-26-11AL media type="custom" key="10200591"

7-26-11AM media type="custom" key="10200599"

7-26-11AN media type="custom" key="10200603"

7-27-2011 did not come in today 7-28-2011 I began the day by scanning a sample of octanethiol on Au(III). The sample was left in solution by Natalie over night. I began the day using tip #7. I scanned the gold on a different sample holder for a short time while Natalie glued a piece of microscope glass to the sample puck. After a short while of scanning without results, I switched to tip #9(1127). I managed to get three total scans with tip #9 but they were not very good.Scan 7-28-11AA was much better than the other two scans, 7-28-11AB and 7-28-11AC."AA" had some definition but it was still not too good of a scan. It was just much better in comparison to the other two. The problematic scans are most likely due to the sample since the etched tips are very sharp and very good. It might have just been a certain area of the sample that might have been damaged somehow or maybe the sample was just not a very good sample overall. Tip #9: 7-28-11AA media type="custom" key="10200707" 7-28-11AB media type="custom" key="10200725" 7-28-11AC media type="custom" key="10200755"

7-29-2011 I came in and began scanning Natalies sample of octanethiol on Au(III) from yesterday with tip #9. I attempted to scan several times but did not find any regions of value so I decided to switch the tip to tip #10 (1128). Around 10:15 a.m., the piezo stack's power supply box started acting strangely and kept turning off while I was trying to scan. I decided that I would just scan the sample on the normal sample holder. Because of this, I will not be able to use the laser today. After lunch, Natalie had me check the voltages of the batteries for the piezo stack power supply. After i checked and recorded all the voltages I went back to trying to scan with tip #10 and the sample on the regular sample holder made for the STM, not the one i use for my project. After a short time of not really getting any good areas to scan I changed the because I thought I might have ruined it by crashing it when the STM was not working properly and the software on the computer kept approaching even after it crashed because it wasn't picking up the current so i had to readjust the clip on the sample puck. I was unable to successfully scan anything at all today. On top of that, the hollow sample holder that Natalie made came apart and the sample holder made for the STM also came apart.This was the final day of my research for my summer. I will resume when the school year begins.