Resonant Ultrasound Studies pnictide superconductors

1. Resonant Ultrasound Studies pnictide superconductors Veerle M. Keppens, University of Tennessee Knoxville, DMR 0804719 The discovery of high-temperature Fe-based superconductivity has resulted in substantial activity leading to the finding of a wide range of Fe-based superconductors, including a number of materials based on the BaFe2As2parent. We have carried out a series of measurements of the temperature-dependence of the resonant frequencies of parent compound BaFe2As2and Co- doped BaFe1-xCoxAs2. The observed reduction in f2 indicates a dramatic softening of cs, as shown in the figure. The amplitude of the effect indicates a strong magnetoelastic coupling, consistent with the observed softening of some phonon frequencies. Relative changes in the resonant frequencies vs. temperature for parent compound BaFe2As2 and Co- doped BaFe1-xCoxAs2.

2. Resonant Ultrasound Studies pnictide superconductors Veerle M. Keppens, University of Tennessee Knoxville, DMR 0804719 Education and training Exposing students to real-world science and the cutting-edge technology with emphasis on the challenges and opportunities associated with Materials for the 21st Century, is of the utmost importance to motivate them to consider future careers that relate to technology. Not only is the training of graduate students and post-docs essential but motivating high school students is imperative to the advancement of science. In addition to the graduate students and post-docs involved in various aspects of this work, several high school students were sponsored through internships to spend one or more semesters in the Keppens lab and have learned different aspects of materials physics through hands on experience and interaction with the group. High school students from Farragut High School (TN) are learning aspects of materials physics and low-temperature technology through direct contact with the group and active involvement in the research.