Understanding the Dynamics of Molecular Solids

Superconductors, single-molecule magnets, and spin-ladders materials are at the center of interest in condensed matter science. All of these materials have incredibly important potential applications and their exploration is the key to the future technologies. We carried out various measurements on representative compounds of each group of interest. The main tool for all these projects was optical spectroscopy, varied in each case to apply magnetic field or change temperature. In our magneto-optical measurements of κ-(ET)₂Cu[N(CN)₂]Br and κ-(ET)₂Cu[N(CN)₂]Cl, we sought to understand correlations between intramolecular vibrations and superconductivity. We found several totally symmetric intramolecular modes that change significantly at the field-induced superconducting to normal state transition. In our polarized vibra- tional and electronic spectra of [(C₆H₁₅N₃)6Fe₈(_µ3-O)2_(µ2-OH)₁₂]Br₇(H₂O)Br.8H₂O, we aimed to understand the charge excitations and benchmark electronic structure calculations. We found excellent agreement with theoretical work. And finally, in our low temperature measurements of (DT-TTF)₂Au(mnt)₂, we sought to under- stand phase transitions and investigate the possibility that this material may be a spin-ladder. We identified and characterized two low temperature magnetoelas- tic and structural transitions. The overall goal of entire work was to understand mechanisms that drive complicated and challenging physical phenomena.