Rutile (TiO₂) has long been known to incorporate hydrogen as OH-  groups when subjected to reducing conditions. More controversial is the possibility of hydride (H-) incorporation as a direct substitute for O2- ions. These hydride defects are predicted to be quite stable (see my DFT study here) but are not extensively characterized. I am currently carrying out experiments exploring the behavior of hydrogen in the oxygen-deficient rutile system.

Stishovite, a high-pressure polymorph of SiO₂ with the rutile structure, is an important component of the deep earth. Recent experiments have shown that stishovite is capable of incorporating significant hydrogen through silicon vacancies coupled to OH- groups (a hydrogarnet-like defect). I conducted calculations to determine the likely configurations of this defect and simulate its spectroscopic behavior, with close agreement to experimental data. Read the paper here.

Transition metal perovskites (especially from the group (Ca,Sr,Ba)TiO₃) are capable of incorporating high concentrations of hydride, sometimes to stoichiometric levels. These phases are not only technologically important, but are also structural analogues to the most abundant minerals in the deep earth. My current work on these materials is focused on inducing and characterizing the hydride defect in SrTiO₃. In particular, I am interested in establishing a frame of reference for detecting hydride in perovskites via vibrational spectroscopy.