Week+of+2-29+and+3-1

2-29-12 I came in today and began scanning a sample of Octanethiol on Au(111) that Natalie prepared. "AA" was very blurry. I tried zooming in and adjusting the parameters and I was correct in my original assumption that the tip was very poor. I stopped it and changed the tip. "AB" was also blurry. It was more clear in this image that the tip was bad because I adjusted all of the necessary parameters and it still had a large amount of noise. I changed the tip after it. The next scan, after adjusting all its parameters, was also very poor. I stopped it 1/3 of the way, cut the tip, and resumed scanning. The next image looked blurry but had plenty of features, I zoomed in on it. I zoomed in to the upper right region. "AD" was blurry but had a lot of features. I changed the tip after it. The next scan also had a great deal of features. I zoomed in and the resulting scan was too blurry to finish so I changed the tip. "AF" had more features than I think any other previous image I have ever had. I zoomed in to the large upper region. I zoomed in to the left middle of this image. The following scan was horribly blurry and I changed the tip halfway through it. 2-29-12AA media type="custom" key="12743932"

This image, although it is clear that it has a large amount of features, has very low quality and low definition. The image is quite fuzzy and this makes it hard for me to gain any knowledge about the Octanethiol molecules on the surface. 2-29-12AB media type="custom" key="12743938" This image also has a very large amount of features but when one looks at the center rift of this image, it is very obvious that the tip is poor from the streaks that run through the whole rift. When assessed, there is no substantial reason to continue on because the smaller zoomed-in images will be even more blurry and will not provide any more insight into the Octanethiol molecules. 2-29-12AC media type="custom" key="12743946" This image has probably the second largest number of valleys ("AF") that I have ever seen in a scan. It is not as clear from this image that the tip is poor. The only evidence for it would come from the top left corner where the image is slightly fuzzy. This image does not have the best definition but because of its incredibly large concentration of features, I wanted to zoom in and see what else I could get. 2-29-12AD media type="custom" key="12743952" This image shows much more clearly the poor nature of the tip. It looks as if it is a smaller image magnified, revealing the blurry pixels at the smallest level. This image is still interesting because it essentially shows me that this is indeed a good sample because of all the features. 2-29-12AE media type="custom" key="12743954" This image, although its left half has a great deal of features, has a blatant lack of definition. This is most well-seen from the small region in the bottom middle. The streaks in this and in the upper left show clearly that the tip was lacking in quality. 2-29-12AF media type="custom" key="12743956" This image probably has the largest number of valleys that I have ever seen. The scanning parameters used in this image were not very well-refined and that is why it was difficult to tell whether it had a poor tip. I zoomed in to the large region on the left side of the image. 2-29-12AG media type="custom" key="12743960" The bottom right corner shows that the tip was not of the highest quality but the features throughout the image show that the tip was a fairly decent tip. The features are fairly well-defined and there is an abundance of them, supporting the idea that the sample is a well-made and well-formed sample.

3-1-12 I came in today and began scanning the same sample of Octanethiol from yresterday. The Piezoelectric stack power supply box was losing brightness on its LED screen and when I turned the voltages down and turned if off, the sample crashed into the tip. I decided I would scan once more before checking the voltages. After the first three successful approaches(with poor results), the STM would not approach. I changed the tip multiple times, restarted the computer and STM, and cleaned the sample holder and apparatus - 4:37 p.m. I finally got it to approach at 4:49 p.m. with some comprehensible quality with a 200 nm x 200 nm scanning region. Unfortunately, the two sides differed greatly in elevation so I zoomed in to the bottom lower right side and continued scanning. This showed that the image was of much less quality than I originally thought. After, I checked the voltages of the batteries.
 * Battery# || Voltage ||
 * 1 || 6.71 ||
 * 2 || 7.83 ||
 * 3 || 6.59 ||
 * 4 || 8.10 ||
 * 5 || 7,93 ||
 * 6 || 8.33 ||
 * 7 || 8.33 ||
 * 8 || 8.34 ||
 * 9 || 8.33 ||
 * 10 || 8.33 ||
 * 11 || 8.32 ||
 * 12 || 8.32 ||
 * 13 || 8.33 ||
 * 14 || 8.33 ||
 * 15 || 8.33 ||

I changed batteries #1 and #3 and then everything worked correctly. After this, I resumed scanning but unfortunately was unable to procure any more results. The poor weather could have been a cause for this decrease in quality from yesterday since it was much colder and rainy than yesterday. This could also help explain the dry spell of results I had through most of the winter. A lack of tip quality and laboratory noise most likely also contributed to this. 3-1-12AA media type="custom" key="12768406" This image has a very large amount of streaks. The hills of this image are ill-defined. The tip on this image was very poor and there is no clear Octanethiol molecules on the surface of this image.