Prof. Dallas Trinkle in Materials Science Has Research Openings for Graduate Students

Prof. Dallas Trinkle in Materials Science is looking for graduate students for two PhD research projects. His group uses and develops new computational materials modeling focusing on electronic structure methods (DFT) to study defects in materials, and build larger scale models using that information. Both involve development of theory and building a computational implementation. Students with interest in condensed matter or materials theory, and computational methods are encouraged to contact Prof. Trinkle for more information.

Density functional theory energy-density method -- The energy density method (EDM) for DFT, first developed by Richard Martin, provides a spatial map of the electronic energy in a material; when combined with integration over atom-centered volumes to remove gauge dependence, the energy of defects can be separated into individual atomic contributions. The Trinkle group has used their implementations of the method to evaluate metal/oxide interfaces, and more recently, steps on surfaces. A new student would expand this methodology to magnetic defects in materials, and evaluate the ability of the energy density method to evaluate spin-coupling in different magnetic materials. Extensions to the EDM for beyond-DFT methods (such as GGA+U) could be considered for the future.

Coupled antisite and vacancy transport in crystals -- Mass transport in materials occurs through the motion of defects: interstitial defects for light elements, or by coupled motion with vacancies for substitutional solutes. In general, such motion is characterized as a correlated random walk. In the case of ordered crystals with two elements, the motion of vacancies is complicated by the creation and annihilation of "antisite" defects (where a chemical element is on an incorrect lattice site). In order for diffusion to take place, a vacancy needs to sample pathways that create defects, but eliminate the defects in a finite number of steps; this is analogous to propagation with Feynman diagrams. A new student would build on previous work in the group using Green function methods for the correlated motion of vacancies, and expand it to incorporate antisite defects. The theoretical work would be implemented into the python framework currently under development for mass transport.

For more information:  http://dtrinkle.matse.illinois.edu