Week+of+10-12+and+10-13

10-12-11 I came in today at 3:30 and the computer and the STM were disconnected and put away. I reconnected everything which took about fifteen minutes, including the time I took aligning the STM with the laser. Then after everything was set up, I began trying to scan the new sample of Octanethiol on Au(111) that Natalie prepared for me. It would not approach or work and then the STM lost connection with the computer. I checked all the cables and the one from the actual microscope to the power box that connects to the outlet and to the computer was not fully screwed in correctly. I tightened the screws and it gained connection with the computer. I tried to approach after this and once more, it did not work. I cleaned the sample holder and the STM where the sample holder lays. I changed the tip after this too nad then tried scanning again. I finally got my first image at 4:44 P.M. This was "AA". It was not very good. I tried zooming into a region on the right side of "AA" but when it started to scan, the quality was so bad that I decided to stop scanning and just move on and change the tip. The actual image of "AB" I scanned after changing the tip was also terrible. It was not as bad as the previous one I attempted to take though and so I tried zooming in to the bottom left corner of the image. This was "AC", and it was terrible, but not as terrible as what I tried to get after "AA", so I changed the tip afterwards. "AD" was fantastic. "AE" was also a great image. I decided to shoot the laser at "AE". I turned the voltage down from 45.0 V to 5.0 V then shot the laser. I then saw that the laser was hitting the wire connecting the piezoelectric stack on the sample holder to its power supply. I tried to fix this without moving the sample holder but I was unable to do so. The sample holder moved and I was not able to get an after image. I re-approached after this fiasco and the three images following were good images, but not good enough to shoot the laser.

10-12-11AA media type="custom" key="10841195" This image was terrible in terms of quality and features. It shows only a few features in a wide 200x200 nm range. It's difficult to distinguish what anything is in this image and it's clear here that the tip is bad. Noise is always a factor but the noise would not make it look this bad. It was clearly the tip's poor quality. 10-12-11AB media type="custom" key="10841211" I took this image after changing the tip following my attempted scan of a zoomed in region of the previous image that proved terrible, too terrible to even waste the time to finish. This image showed a bad tip as seen in the horrible resolution. There are few features that one can see. I tried to see if I could make anything out of a zoomed in region of this image. I zoomed in to the bottom left corner. 10-12-11AC media type="custom" key="10841227" In retrospect, I probably should not have finished scanning this image. This image confirmed the terrible tip present in the previous scan and showed no easily recognizable features such as valleys, hills, or Octanethiol. I changed the tip after because of the terrible quality. 10-12-11AD media type="custom" key="10841237" I took this image after changing the tip and the first half of the image was great. However, about halfway through, the image started to show great changes in topography so I had to lower the resolution to continue scanning and seeing some stuff. This image showed a large amount of features, mostly valleys and several hills. I tried to zoom in to the middle of the right side of this image for a better image.

10-12-11AE media type="custom" key="10841285" This image showed a high amount of valleys and a pretty good amount of hills. It's possible that some Octanethiol can even be seen in this image. However, the streaks that look similar to what Octanethiol would look like are most likely streaks caused by the tip or by noise. I tried to shoot the laser at this image but as described in the situation above, I was unsuccessful. 10-12-11AF media type="custom" key="10841293" I took this image after fixing the wire and approaching. This image was a pretty good image. There are many recognizable features throughout the image and had I scanned at a higher level of resolution, we would be able to see them better. 10-12-11AG media type="custom" key="10841311" This image was not as good as "AE" was but the upper right corner extending to about halfway towards the middle of the image going downwards and more than halfway going to the left had a lot of potential for a future image. It wast the most defined part of the image and the features looked the best there. Although we cannot see Octanethiol on that part, it was possible that we could have seen it by zooming in and getting a well-defined image. Unfortunately, we were not so lucky. 10-12-11AH media type="custom" key="10841323" I tried zooming in to the top right corner area of the previous image and when I went to click the "Start" button on the computer, I accidentally clicked the button to the right of it which caused it to move upward. This image still have some pretty clear features: the four clear valleys and the one obvious hill in the middle. The tip's quality seemed to have diminished by this scan as one can see by the image's streaks. It's tough to see if there is any Octanethiol. 10-13-11 10-13-11

I came in today at 3:40 and began scanning the same sample of Octanethiol on Au(111) from the previous day. The first image I got was not very good but I tried zooming in to see if I could get better results. This is not what happened and "AB", my second image, was just as bad, as the first image, if not worse. I changed the tip after "AB" and took "AC". "AC" was also awful and I changed the tip after. The STM has not been working very well and has not been approaching. It is already 5:00 p.m. and I have only approached successfully two times. At 5:05, I managed to get it to approach and this image was once more awful. I changed the tip afterwards and tried to approach again. It would not approach again for another 8 minutes at 5:13. This image I got was not as bad as the others had been. This was "AD". I zoomed in on the right upper corner this image in the hope of finding something. My endeavor was unsuccessful. The image was terrible. There was no definition or features. I changed the tip after. The STM would not approach again for the rest of the day despite my multiple tip changes. I also tried to get it to work by restarting the program on the computer and restarting the microscope's hardware. None of these attempts proved successful. Today was quite possibly the worst day I have ever had in lab. Another factor that could have influenced the ability of the microscope was the change in weather with the rain. I doubt this affected it much but it could have had a small impact on the quality of the scans or the ability of the microscope. Most of the terrible quality of the images is due to the poor quality of the tips which is my fault. Noise also contributed to the poor quality. The sample could have also been scratched. It also might have diminished in quality over time or it might have never been a very good sample to begin with which might explain yesterday's atrocities and would have put me a predisposition for scanning quality. With all these possible factors, it's difficult to pinpoint the most important one. However, I think that it was mostly due to poor tips rather than anything else. 10-13-11AA media type="custom" key="10859598" This image showed no definition and no features.The tip was awful. 10-11-11AB media type="custom" key="10859602" This confirmed even more that the tip used in the previous image was awful. There is even less definition in this image than in the previous image and there are no features. 10-13-11AC media type="custom" key="10859612" This image was atrocious. There was no definition and there were no features at all. This was also a terrible tip. I changed it afterwards. 10-13-11AD media type="custom" key="10859606" This image had no definition or features either. I changed the tip after. 10-13-11AE media type="custom" key="10859620" This image, like the others, had no definition or features. I could not get the STM to approach again after this. It is quite possible that it was not the quality of the tips that caused the poor quality of the image. It is quite likely that the sample had diminished in quality from yesterday, when I also did not get very good results. It's also possible that the increase of humidity due to the rain could have impacted the ability to scan but it is not likely it would have negatively affected it a large amount.