Elizabeth Lindquist, Anna Lunderberg, and Anna Wormmeester presented their research from the summer of 2016 at the Wayne State University CUWiP poster session.
Rylan Prafke won an award and the 2016 Annual Meeting and National Student Conference of the American Institute of Chemical Engineers (AIChE). His presentation “Response of Surface Bound Hexacyanoferrate Films to Binary & Tertiary Metal Alloy Compositions” was co-authored with Dr. Jennifer Hampton, associate professor of physics.
Jacob Pledger also presented at the conference. His work “Crystalline Channeling of MeV Ion Beams,” which was co-authored with Dr. Stephen Remillard, associate professor of physics; and Dr. Paul A. DeYoung, who is the Kenneth G. Herrick Professor of Physics. It also appeared in the “Materials Engineering and Sciences 8” category.
Friday, October 14
Exploring the Effects of Copper on Composition and Charge Storage of Prussian Blue Analogue Pseudocapacitors
As energy usage has increased in recent years, there has been great demand for efficient, cost-effective, and earth-abundant materials to be used for energy storage. The ability to produce hexacyanoferrate (HCF) modified nickel film for use as a pseudocapacitor has already been demonstrated. This project focuses on the effects on the modification procedure and the resulting material of adding copper to the nickel metal film. A NiCu film was deposited onto a gold substrate with a controlled potential electrolysis experiment, then was modified and characterized with a cyclic voltammetry experiment. The composition was determined with a scanning electron microscope with energy dispersive x-ray spectroscopy before and after the modification process. Copper was selectively removed in some cases as a result of the modification. With increased levels of copper, the material can become structurally unsound and result in unintentional stripping of the material. Preliminary data suggests that as the pre-modification level of copper is increased, the resulting charge storage of the HCF film increases as well.
Scanning of the Intermodulation of Superconductor Resonators
At the resonant frequency, superconductor resonators produce intermodulation distortions, smaller signals near the resonant frequency. By inducing external microwave signals, it is possible to analyse the patterns of intermodulation distortions (IMD) in several different types of superconductor resonators. These measurements can be used to complement the main peak values like quality factor and frequency shift in order to understand nonlinearities present in the material of the superconductor. Once spatial distributions of IMD have been identified, they can be used to interpret IMD signals from unknown superconductors and identify various defects in the crystal structure. Using a probe outputting two combined tones into the resonator, it was possible to map the whole of a two-dimensional resonator, using the IMD as the z-direction. In order to best resolve the intermodulation distortions, two superconductors were imaged, a hairpin wide-line resonator and a thin, line resonator. A contour plot of the data was then generated, which displays the IMD of the given resonator.
Determining the Nuclear Structure of an Unstable 25O Isotope
One of the primary goals of nuclear physics research is to better understand the force that binds nucleons. This can be accomplished by studying the structure of neutron-rich isotopes. For this experiment, excited 25O nuclei were formed by a collision between a 101.3 MeV/u 27Ne ion beam and a liquid deuterium target at the National Superconducting Cyclotron Laboratory. One resulting reaction involved two-proton removal from 27Ne particles, which created excited 25O nuclei that decayed into three neutrons and an 22O fragment. The four-vectors for the neutrons and 22O fragments were determined, allowing the calculation of the decay energy for this process on an event-by-event basis. However, another reaction would also take place, in which an alpha particle was stripped from the beam, creating 23O nuclei that decayed into an 22O fragment and a single neutron. In order to distinguish between 22O fragments and neutrons from both 25O and 23O isotopes, members of the MoNA collaboration are conducting GEANT4 simulations of each decay process in order to uncover their distinguishing characteristics. By successfully correlating simulated decay processes to experimental data, the relative cross sections of the two decay processes will be determined, and their decay energies will reveal more about their nuclear structures.
The Physics Department welcomes Prof. Geoffrey Lenters from Grand Valley State University. Prof. Lenters is visiting in our department during the fall 2016 semester and is working with Prof. Remillard on optical spectroscopy of microplasma emissions. As an astrophysicist, Prof. Lenters brings critical knowledge of plasmas and their optical emissions to the project. Please stop by the Microwave Lab in Vanderwerf Hall to greet Prof. Lenters.
Research Advisor: Dr.Stephen Remillard
Thin films of strontium titanate (SrTiO3) on single crystal magnesium oxide (MgO) substrate and strontium manganate (SrMnO3) also on single crystal MgO substrate are being considered for use in engineered superlattices. These superlattice structures exhibit unique properties which make them valuable in the semiconductor industry as well as applications which require a high sheering resistance. Crystal matching of the films to the substrates, which is essential for a low defect density, is indicated by effective channeling of ion beams through the lattice. Ion beam channeling, which occurs when the beam’s incidence angle is parallel to crystal planes, can occur in well-ordered and pure crystals. With the addition of the ability to control the azimuthal angle as well as the altitudinal angle, two dimensional rastering of the incident angle is achieved. Comparison of the backscattering yields at different incident altitudinal and azimuthal angles shows a drop in yield as the channeling angle is approached. Channeling is seen in both the bulk SrTiO3 and MgO samples, although the yield suppression revealed structure around normal incidence. This structure is observed to be consistent between two MgO samples obtained from different suppliers and has different spacing in peaks than the SrTiO3 sample.
This research was supported in part by an award to Hope College from the Howard Hughes Medical Institute through the Undergraduate Science Education Program and by the Hope College Department of Physics.