My research interests span the broad areas of functional oxides (particularly oxide interfaces) and crystal structure prediction algorithms. This may seem like an unusual combination of interests, but as a materials physicist, I study the relationships between the structure of materials and the physics of their properties. The problem is that we often have only limited information (both experimental and theoretical) about interfacial structures, so we currently have a poor understanding of the ways in which interface structure affects material properties. If this problem were solved, scientists could confidently design interfaces with desired properties, such as tunable electrical conductivity or increased toughness. I was recently part of a team that designed a genetic algorithm to predict the structures of interfaces in materials composed of multiple chemical species (we studied grain boundaries in a technologically important oxide, Strontium Titanate SrTiO3). This work represents a significant step towards solving the crystal structure prediction problem for systems in which the global energy minimum is not the target. You can read more in our Nature Materials paper here.
I am currently researching the theory of phase transitions in layered perovskite oxides, in particular, Ruddlesden-Popper (RP) phases. The RP phases provide ideal ‘laboratories’ for studying the effects of reduced dimension on electronic properties. RP materials are structurally similar to some high-temperature superconductors and display a wide range of interesting properties: ferromagnetism, ferroelectricity, superconductivity and metal-insulator transitions. I try to link the lattice dynamical properties of RP oxides (phonons and phonon dispersion relations, interatomic force constants) to their structure and chemistry.