Week+of+1-25+and+1-26

1-25-12 I came in today and the table that held all of my resources had been moved to accomodate for George and Matt's experiment. All of my stuff was packed away and I spent the first 30 minutes in lab reassembling and realigning the laser apparatus, the STM, the computer, and the laser power supply. Afterwards I began scanning a sample of Octanethiol on Au(111) that Natalie prepared. The first tip was extremely poor and this forced me to stop the scan halfway through and change it. The same thing happened with the second tip but it was slightly better. Then, while changing the tip after my second attempt, I noticed that the LED screen on the Piezoelectric supply box was slowly fading. I opened up the box and checked the voltage of all the batteries.as


 * Battery Number || Voltage ||
 * 1 || 5.53 ||
 * 2 || 8.35 ||
 * 3 || 8.35 ||
 * 4 || 8.36 ||
 * 5 || 8.36 ||
 * 6 || 8.36 ||
 * 7 || 8.35 ||
 * 8 || 8.35 ||
 * 9 || 8.38 ||
 * 10 || 8.38 ||
 * 11 || 8.37 ||
 * 12 || 8.39 ||
 * 13 || 8.39 ||
 * 14 || 8.39 ||
 * 15 || 8.38 ||

I changed battery #1 and everything began working as it should. I managed to get a couple images before the day was over but none of them was too great.

1-25-12AA media type="custom" key="12245174" This image shows a definite double tip: each feature has what is like a shadow caused by this double tip. The hills and valleys are somewhat undefined because of this and it's very difficult to obtain anything of importance from this image.The diagonals throughout the image show a possible, but unlikely arrangement of Octanethiol molecules. 1-25-11AB media type="custom" key="12245184" There is an increased amount of noise in this image. The diagonal arrangements appear again in this image but they appear to be more so caused by the STM than to be actual Octanethiol molecules. I had planned on shooting the laser at this image to see what would happen. However, Natalie tried to do something with the spectroscopy panel to attempt to eliminate the double tip present in this and the past image, eventually resulting in a loss of time and position.

1-26-12 I came in today and began scanning the same sample of Octanethiol on Au(111) from yesterday. The first image,"AA", showed a pretty wide selection of features. I zoomed in to the top right quadrant. This next image, "AB", was decently blurry after adjusting some parameters, making it more obvious that the tip was not very sharp. I cut the tip afterwards. The next image, "AC", was decently blurry but also had an incredibly large amount of hills. I zoomed in to the bottom left quadrant but found it too blurry to finish. I changed the tip. The next scan proved fruitless with its unbearable blurriness. The following scan provided an equal or higher amount of incomprehensible junk compared to the previous scan. An annoingly long time period of about 30 minutes passed before I was able to get another scan. The STM continually crashed or bottomed out. Then when I was finally able to scan, the image was horrible. I was unable to get anymore decent scans the rest of the day. When trying to get the STM to work, I had tried cleaning the sample holder and landing, restarting the STM, and changing tips before it finally worked. One thing I noticed when I was changing the tip was that this particular tip was shorter on the side facing the sample than the amount of tip extended on the tip holder. It may just be coincidence but after I moved it forward I was finally able to get the aforementioned horrible scan that I did.

1-26-12AA media type="custom" key="12245264" This image showed a very high amount of features and its lack of definition is caused by the scanning parameters used here. It held high hopes for a possibility of atomic resolution and high quality features. However, another look at the bottom right and middle left regions suggests that it was not as defined as I had originally thought. I zoomed in to the top right quadrant. 1-26-12AB media type="custom" key="12245270" This image unfortunately shows no atomic resolution and went contrary to my original hopes of it being a good tip. This image is simply noisy and not well-defined. I changed the tip after it.

1-26-12AC media type="custom" key="12245282" This image shows an intensely high amount of noise. It is not well-defined and neither are the features. There are streaks throughout and it is clear that atomic resolution is unlikely with this tip. However, I wanted to make sure it was not simply the scanning parameters and zoomed in to the bottom right quadrant. My original thoughts were correct though and it proved even more to me that the tip was dull.