Week+of+Aug+31-Sep+4

= Week of Aug 31-Sep 4 =

September 2nd
Today I didn't get very good scans, but I more so preped for lab work on Friday. I cleaned of the sample holder of dust from the microtherm thin-sheet insulator and I cut a new piece of microtherm thin-sheet insulator for the sample holder and cut a hole in it so that the laser could be shot through the back of the sample holder. Becky annealed a piece of gold and I then attached this to the sample holder. Immediately after we anneal the gold we usually put the sample in the scope and wait for a short period for the sample to equilibrate. The scans are extremely drifty immediately after the gold has been annealed. I also cleaned off the end of the laser. The last time I did this the laser spot became very crisp and less hazey so I do this occasionally. After doing all of this I attempted to scan. The scope was working properly, but it was very drifty seeing that the piece of gold was recently annealed. It was also very humid in the lab. This again brings up the thought that the temperature and humdity can affect the scope.But today I was switching stuff out and did some scanning. There weren't any really good or particularly interesting images. Today I did not shoot the laser at the sample. I did however find out a little bit more about why I am trying to heat up the surface of the gold. Becky and Annette said the reason I was doing this is to develop a tool that they can use in their projects. If I am able to create a controlled temperature increase with a laser then they could use this to remove molecules or "junk" that they do not wish to see on the surface by changing the temperature in a way that it will only remove these molecules, not the ones they wish to see. For instance the gold will change if you increase the sample 50 degrees Celsius. However, they may be other molecules on the surface that you can remove if you raise the temperature 20 degrees Celsius. So by heating it 20 degrees Celsius you remove these molecules, but you do not effect the gold itself. Aside from this the other reason that I am shooting the laser at the gold is to see if I can actually alter the surface of the gold.

September 4th
Today was a good day in the lab. While my scans were not very clear (they were better though than they have been the last two weeks) I did get some good data from them. In the past the largest amount the gold expanded was between 2500-3000 Angstroms. Today the first time I shot the laser during a single line scan the needle went entirely across the feedback with a z-position of 2. So I turned the z-position down to one in order to allow it to travel farther. I started the needle at the far left of the feedback and when I shot the laser it went almost all of the way across to the right. When I opened the image after the scan and did a section view of the image I found out that the gold had expanded 4000 Angstroms. This was a significant amount larger than what we had gotten in the past. What seems to be the only explanation for this significant change is that the laser was aligned better. I ran a couple more single line scans and the 4000 Angstrom increase was the lowest increase of all of the single line scans. The largest increase was 4500 Angstroms. I also took scans before I shot the laser and after I shot the laser. I got two images that might be the same area. There are three features that look the same, however some things new features appeared after the laser was shot. It is hard to distinguish if these two images are in fact the same area. Something that I have to figure out how to do is overlap the two pictures. If the features match up then this would be very intriguing because the laser has then changed the surface of the gold. The numbers of these scans are 09040900BD and 09040900BI.



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