Summer Research Experience for Teachers
In the summer of 2013, the following teachers joined the MRSEC team:
"This summer my project has been programming Mathematica to calculate electrostatic energy due to dipole-dipole interactions for various configurations of polar molecules on metal surfaces. Our goal is to determine whether particular arrangements are energetically favorable in an attempt to understand why different combinations of molecules and surfaces result in different alignments. The results of our research will hopefully help to explain the role of electrostatic dipolar interactions in the organic self-assembly on surfaces where competing forces determine the outcome of the self-assembly."
"This summer I continued to do research with Professor Ducharmes' group. My experiences began a new pathway with the training and building of thin film polymer slides and their development and use as capacitors. This has been a main emphasis of the group, and it was very interesting and beneficial for me to be involved in this aspect of the research.
Besides this, I continue to assistance in the educational outreach of Nanotechnology and MRSEC research to Nebraska science teachers and students. Examples this summer were a teacher workshop in cooperation with NCMN and also 2 Nanotechnology camps through Bright Lights for middle school students."
"This year I worked to help graduate students with their research. It was very rewarding, and I keep learning more about materials. I plan to include more crystal structure information in my chemistry classes."
"This summer I continued working with different materials used as dielectrics in capacitors. I learned how to make thin film capacitors using the spin-coating technique. Liquid solution containing the crystal material we are studying can be slowly added to a substrate spinning near 2,000 rpm's which produces a relatively uniform thin film approximately 30 nm thick. Capacitance measurements are then made at different frequencies and voltages to study the ferroelectric properties of the material.”
"This summer I focused on the analysis of tunneling and ballistic currents in two types of samples:
- LSAT (LaAlO3)-substrate, LSMO (LaxSr1-xMnO3) and PZT (Pb[ZrxTi1-x]O3) – thin films
- STO (SrTiO3)-substrate; SRO(SrRuO3) and BTO (BaTiO3)-thin films
The multilayered thin films were produced using Pulse Laser Deposition technique. I was responsible for making a lithographic mask on the surface of the samples, which was used for creating a gold contact surrounded by a layer of titanium oxide (semiconductor). Both, gold and titanium oxide, were deposited on the service of the samples by sputtering method."
"This summer I was involved with Dr. Adenwalla’s group studying the magneto-electric effect, more specifically, the magneto-electric coupling between a ferroelectric organic thin film and ferromagnetic thin film. My focus this year was on collecting pyroelectricity data and assisting with the refining, testing, and use of the new oligomer evaporation chamber used to deposit the organic thin films.
To study the magneto-electric effect, I assisted by preparing substrates and operating the three separate deposition chambers, including the new organic evaporator, needed to create the samples. I've conducted pyroelectricity measurements to determine if a pyroelectric current could be established from the bottom electrode to the top by polarizing the oligomer (VDF) layer in between the two electrodes. Pyroelectricity is observed by using a laser to modulate the temperature across the crystal structure, which then results in a potential difference. The observed pyroelectric current is directly proportional to the polarization of the ferroelectric layer.
My involvement with the new evaporator included operation of the unit, assisting with its calibration by comparing the projected thickness of the material against the actual, and testing to see if VDF was actually deposited on to the substrate by using x-ray diffraction (XRD). Cooling the evaporator allows the VDF to condense on the substrate in its ferroelectric phase, so liquid nitrogen (LN2) was added to a reservoir built into the top of the evaporator. Initially, LN2 was poured by hand into the reservoir from a small dewar. I was able to develop another technique where the LN2 was added directly to the intake tube of the evaporator via an insulated copper pipe connected to our 230 liter LN2 dewar. This technique allowed for lower deposition temperatures and more convenient operation when compared to the previous method. Finally, I was safety trained in the areas of lasers and radiation."