Summer Research Experience for Teachers
In the summer of 2014, the following teachers joined the MRSEC team:
Pam Rasmussen, Raymond Central High School
worked with Jeffrey Shield, Mechanical & Materials Engineering.
"I once again have been blessed with a chance to work in Professor Shield’s Lab under the MRSEC. Each year I go back to school refreshed with new tales to tell my students about life of a Grad Student. I wish I had kept data on the number of my students who now enroll in engineering compared to the number before I began with the MRSEC. I know there would be a significant percentage increase. As for work, I particularly appreciate the new x-ray machine. It makes analysis of samples quick and easy."
Steven Wignall, Seward High School
worked with Stephen Ducharme, Physics.
"This summer I continued to do research with Professor Ducharmes' group. My experiences began another new pathway with the fabrication of different Diisopropylammonium (DIPA) salts. My role was to grow these salt crystals and try to find a reproducible way of doing this consistently. This has been become a new 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 NCMN and MRSEC to Nebraska science teachers and students. This summer the outreach grew considerably with my involvement in 8 activities. There were 3 teacher workshops in cooperation with NCMN and also 3 Nanotechnology camps through Bright Lights and Upward Bound for middle and high school students. Also added this summer was a 3 week STEM activity with 120 students at Culler Middle school in Lincoln.“
Eugene Kirianov, Lincoln Southwest High School
worked with Andrei Sokolov, Physics.
"I was very pleased to continue my work with A. Sokolov's group, which is generally aimed at investigating the possibility of controlling magnetic and structural properties of materials by applied electric field. This summer, our research was focused on the fabrication of thin films of NiMnIn magnetic shape memory alloy on different substrates. We were interested to elucidate their effect on epitaxial growth and the possibility to observe martensitic transformation in bounded thin films. The key point of this study, which defined my role in this project, was to visualize the substrate, thin film interface, using the High Resolution Transmission electron Microscope (HRTEM) that was recently installed at NCMN. To observe the samples in HRTEM, they needed to be thinned to approximately 50-100nm in their cross-section. The thinning of the samples was conducted in two steps. First, I thinned the samples to approximately 50-60 μm using the Allied MuliPrep Polishing system. Second, using Focused Ion Beam Microscope (FIB), a sample was mounted on a half grid and thinned further to 50-100nm using H-bar milling technique. As a result, we were able to investigate the interface that will provide further optimization of fabrication of magnetic alloys studied in our research."
Mark Shearer, Lincoln Southwest High School
worked with Shireen Adenwalla, Physics.
"My focus this summer was on testing and characterizing ferroelectric thin film samples created using an organic thermal evaporation chamber. The ferroelectric vinylidene difluoride (VDF) was grown atop a ferromagnetic thin film (cobalt) to study the magnetoelectric coupling between the ferroelectric and ferromagnetic layers. However, depositing VDF in the proper ferroelectric crystalline phase is very difficult and requires a very specific set of deposition parameters (substrate temperature, deposition rate, etc.). Therefore, much effort was put into finding and characterizing this correct set of deposition parameters.
I assisted by preparing substrates and operating three separate deposition chambers, including the organic thermal evaporator, needed to create the samples. Typically, the structure of the samples was as follows: glass/Pt (50nm)/Co (8-15 Å), vinylidene difluoride (VDF)/ Al (30-80 nm). I then conducted pyroelectricity measurements to determine if a pyroelectric current could be established from the bottom electrode to the top by polarizing the VDF 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.
I then determined the magnetization direction of the ferromagnetic layer by utilizing a method known as the Magneto-Optic Kerr Effect (MOKE). MOKE uses reflected polarized light from a sample subjected to a magnetic field allowing us to determine direction changes in the magnetic domains. Finally, once the magnetization direction of the cobalt was known, I looked for changes in this magnetization as a function of VDF polarization."