NSF Nugget for FY06 Investigating the scattering processes in MgB 2 Work in the group of Newman and Rowell, Arizona State University, DMR Sept FRG on Two Gap Superconductivity Wisconsin-Penn State- Arizona State-Puerto Rico- Mayaguez collaboration DMR PI David Larbalestier, Eric Hellstrom and Paul Voyles (UW), Zi-Kui Liu (Penn State), Nate Newman and John Rowell (Arizona State), and Oswald Uwakweh (U. Puerto Rico Mayaguez)

Investigating the scattering processes in MgB 2 Work in the group of Newman and Rowell, Arizona State University, DMR – in collaboration with Xi (Penn State) The green area consists of data taken from samples that were damaged using high energy particles and carbon doped bulk samples. It seems that O doping also enhances Hc2 though not as strongly as C. Understanding the role of scattering processes in MgB 2 is of great practical importance as H c2 of C- doped MgB 2 films exceeds that of Nb-based conductor materials. Carrier scattering can be altered by varying the synthesis process, by doping, and by energetic particle irradiation. The effect of damage induced by 2-MeV alpha particles, followed by annealing, on the critical temperature (T c ), resistivity (  ), and upper critical field (H c2 ), of MgB 2 films made by different deposition processes has been studied. We also study the incorporation of oxygen into MgB 2 films grown by MBE (at ASU). To increase carrier scattering, which in turn increases H c2, many groups have doped MgB 2, particularly with carbon. We find that MgB 2 films with high oxygen content have reduced T c but enhanced H c2.

Education: Substantial progress has been made in designing and developing the project Science is Fun modules that address the National and Arizona Science Education Standards (Physical Sciences) associated with magnetism for elementary grades. Under direct supervision, two Science is Fun senior Interns have compiled a variety of exciting explorations for the modules. Field testing of the 15-minute presentation is expected to begin during the second half of the Fall semester, with field testing of the 45-minute presentation to begin in Spring Societal Impact: A fundamental understanding of the scattering processes occurring within MgB 2 is essential for MgB 2 to reach its full potential. Once a reliable means of increasing H c2 is obtained, MgB 2 will be ready to compete with the existing Nb- based superconductors from which all MRI and high field magnets are made. Investigating the scattering processes in MgB 2 Group of Newman, Arizona State University, DMR Please visit