Dr. Kaspar has nearly 20 years of experience with epitaxial oxide deposition by oxygen-plasma-assisted molecular beam epitaxy and pulsed laser deposition in the Oxide Epitaxy Laboratory at PNNL. Her expertise centers on systematic structural characterization of epitaxial films with scattering, spectroscopic, and imaging techniques. This information is then combined with the evaluation of electronic, magnetic, photocatalytic, and/or piezoelectric properties to establish structure–property relationships that provide insight into the physics underlying observed phenomena. The role of intentional and unintentional defects (e.g., dopants, cation and anion non-stoichiometry, misfit dislocations) on oxide structure and properties is a running theme of Dr. Kaspar’s work.

Previous work focused on the magnetic properties of transition-metal-doped TiO2 and ZnO as potential dilute magnetic semiconductors. More recent work has investigated the electronic, photoactive, and magnetic properties of doped binary and complex oxides. Particular emphasis is placed on the relationship between the electronic changes that occur with doping and the resulting photoabsorption and carrier generation processes. Other recent research areas have included the synthesis of lattice-mismatched epitaxial metal films on oxide substrates for both mechanical deformation and radiation damage studies, the development of new complex oxides as high-temperature, radiation-resistant piezoelectrics for use in advanced in situ sensors, and fundamental investigations into radiation-enhanced cation and anion diffusion mechanisms using isotopic tracers incorporated into epitaxial oxide thin films.