The MRSEC provides up-to five metro-Atlanta high school physics teachers a research experience every summer. The objective of the program is to familiarize participating physics teachers with the modern materials and physics concepts and their applications to engineering as well as their relevance to today’s technology. Each teacher works on an individual research project with a MRSEC faculty.
Participants get unique opportunities to:
- Have a 8 week research experience at the state-of-the-art MRSEC facilities
- Receive a $6,000 stipend
- Attend MRSEC seminars, lectures and journal club
- Participate in professional development activities
- Prepare a research-based lesson plan
The 2013 program will run from June 3 to July 26. The program will start with a half-day orientation and end with each participant giving an oral presentation on the last day of the program. Teachers will be admitted and hired through the STEP-UP program. Interested teachers can apply to the program on-line by completing the STEP-UP application form.
The MRSEC research projects are challenging and many have outcomes that could directly be used in technological applications in the near future. The Center faculty developed techniques for using the material “graphene”, that is recognized in the physics Nobel Prize in 2010, in electronic devices. The abstracts of the past year teacher research projects are provided in the table below. Each teacher’s research presentation can be viewed by clicking on her/his project title.
|GT MRSEC RET 2014|
Participant Name & Affiliation
|Molly Golloday – Shiloh High School||Modeling the Electronic Behavior of Twisted Bilayer Graphene|
We are interested in the interlayer coupling between two layers of graphene rotated at small angles. Using a computational model of this system, we study the band structure as a function of interlayer bias, altering the Fermi surface. The first star approximation of this band structure has already been well explored, so we turn our attention to the next significant level of interaction. We verify that when accounting for these interactions, our theory is still in agreement with experiment so that we may turn our attention to less studied cases of bias.
|Cisely Marshall – Booker T. Washington High School||Measuring the Height to Angle Ratio of Dimpled-ground SiC Samples|
The growth of epitaxial graphene on SiC has been shown to begin at step edges. Therefore, control of the step-edge density and step bunching on the substrate is important for the production of large-area and high-quality graphene. Here we study the kinetics of graphene growth as a function of SiC step morphology by using dimple-ground SiC samples. This method of sample preparation allows for the study of a continuous range of miscut angles, prepared under identical growth conditions. Samples are annealed inside a graphite furnace with the flux of silicon controlled via physical confinement and a controlled background pressure of argon or silane. The morphology and graphene coverage of the samples are characterized in-situ with LEED and Auger spectroscopy and ex-situ by AFM, SEM, and Raman spectroscopy. The height to angle ratio of the dimpled-ground SiC sample was measured using Veerco AFM to determine if any source of oxidation occurred over a given time period. An alternation of large and small terraces, separated by steps of 0.75 nm heights are observed and only for well defined azimuthal directions, equally spaced terraces separated by steps of 1.5 nm height are found. In addition, the polar variations have been studied by taking various line-scans along the concave-shaped surface with AFM. It seems that for polar angles above 3°, step bunching of several SiC steps occurs whereas below 3° the bimodal terrace width distribution is observed.
|John Nice– South Gwinnett High School||Electronic Properties of Graphene Nanoribbons|
Graphene Nanoribbons can be modeled utilizing the tight binding method. The project was to write a code that would model the energy bands for various ribbon configurations of varying thicknesses. The two configurations modeled were the armchair and zigzag configurations. The program looks only at effects on band structure due to nearest neighbor atoms. The band structures modeled is consistent with what is seen in the literature.
|Karen Porter-Davis – Chamblee Charter High School||Super-resolution Imaging of Frustrated Phagocytosis|
Actin is the most prolific protein in almost all of eukaryotic cells. It plays many roles in the cell including the maintenance of the cell’s shape and muscular contraction. The Curtis group is interested in the characteristics and forces involved with the actin cytoskeleton during phagocytosis. To study and understand this process it is important to produce clear images of the cell’s cytoskeleton and especially the actin protein. Optical microscopes are unable to produce these clear images of such small structures within the cell due to the diffraction limit of the optics. To reduce this obstacle a super resolution microscope, specifically, a structured illumination microscope (SIM) was used. It is important to note that this is a type of fluorescent microscopy and the cells are treated with a fluorescent dye to make particular parts of the cell easier to detect. The SIM, specifically, uses interference patterns superimposed on the sample that are rotated a certain number of times while images are being taken. This captured raw data is then processed with an algorithm to create an image that has an axial resolution range around 150 to 300 nm. In particular, the Curtis group employs this super-resolution microscopy to investigate the organization of the actin cytoskeleton in macrophages during frustrated phagocytosis and to look for the presence of a contractile actin ring.
|Malynda Wood –Southwest DeKalb High School||Temperature Optimization of the Generation of Graphene via Hydrogen Passivation|
The purpose of this project was to determine the optimum conditions for producing monolayer graphene on a silicon carbide substrate through hydrogen intercalation. A sample that had been grown at 1100C in an earlier project had proven to be damaged by the high temperature intercalation process. Several samples were hydrogen passivated between the temperatures of 700C and 1000C using the FirstNano Graphene Furnace. The samples were evaluated by Raman Spectroscopy. A comparison of the D peaks and 2D peaks in the Raman Spectroscopy indicated that there was less disorder in the sample intercalated for two hours at 900C than in samples intercalated for lower temperatures indicating that the intercalation was not complete for those times and temperatures. Leaving the sample in for longer periods of time causes larger D-peaks due to damage done to the graphene due to reactions between the graphene and the hydrogen. Higher temperatures seemed to accelerate this damage giving Raman signals that once again had larger D-peaks and smaller 2D-peaks even at the two hour time. When a sample was intercalated at 900 C for ten minutes, it had a small, narrow D-peak and a large, sharp 2D peak. While this sample still had a significant D-peak indicating defects, the 2D-peak was even larger in comparison to this D-peak than in the 2 hour sample, indicating that while 900 C seems to be the optimum temperature, the optimum time may be shorter than was originally expected.