First+Semester+Final+Exam+Draft

For the majority of my senior year thus far, I have been using Scanning Tunneling Microscopy to research the effects of heat on surfaces coated with Buckminsterfullerene(C-60). Unfortunately, however, I ran into two major problems while doing so. The first major problem was that the scope was heavily contaminated with thiols and after about an hour or so of scanning, thiols could be seen forming on the surface of the samples that were supposed to have C-60. This would corrupt our results. The second major problem was that the tip used for scanning became lodged inside of the piezoelectric tube and it was impossible to remove. This made it difficult to place in other tips stably and it immensely decreased the quality of the scans. Matt and I concluded that, in order to move forward and get applicable results, we would need to design a new scope. The design for the new scope will utilize a Peltier to control the temperature of the sample. It will still use the resistor to heat the gold sample directly while the Peltier will cool it. I have chronicled the assembly of the power supply for the Peltier here: https://sjhsrc.wikispaces.com/Week+of+11-19-2012 and https://sjhsrc.wikispaces.com/Week+of+11-26-2012 .The temperature controls will allow for more efficient scanning as scanning is more often than not affected negatively by the temperature fluctuations in the lab. The scope we will be using will be much more compact than the current one. I am not particularly certain on the exact design of it because the most important metal for its design, invar, arrived while I was on break and Matt was still finalizing the designs. Following break, I will begin assembling the scope with Matt. Matt and I did have to design a specific circuit board to act as an input switch for this new scope and that process can be seen here: https://sjhsrc.wikispaces.com/Week+of+12-16-2012. I will continue to update this post as I work more on the scope’s assembly. We hope to have it finished and running by mid to late January.