Theodosios Famprikis

I am broadly interested in how atomic-scale dynamics and disorder influence the properties of functional materials. With dual expertise in both experimental and computational approaches, I apply synthetic methods, diffraction and spectroscopic techniques, as well as computer simulations in my research.

Ion conductors

Much of my work has focused on the fundamental mechanisms by which ions move through solids—critical for electrochemical applications such as batteries, sensors, ionic transistors and many others. While the phenomenon of ion conduction has been known since Faraday, many unanswered questions remain such as how the movement of ions correlates with dynamics of the host lattice (phonons) and how does atomic scale disorder modulates macroscopic ionic conductivity.

On the latter question, for example, our recent work (link) provided new insights into this question, made possible through a novel computational analysis framework. We demonstrated that, synthetically we can introduce anion disorder in the host lattice using mechanochemistry and we showed that in the case of anion-disorder, the problem can be thought of as the anion disorder breaking the degeneracy of local cation-hopping barriers, enabling facile long-range percolation paths. Thus in this case local disorder helps promote macroscopic ion conduction and offers a promising design lever for improving existing materials and discovering new ones.

Plastic Crystals

More recently I have investigating an underexplored phase of matter termed plastic crystals or rotor phases. These so-called mesophases exhibit characteristics of both solids and liquids: while maintaining long-range order and solid-like mechanical stability, they locally exhibit dynamic disorder and pronounced atomic mobility reminiscent of liquids. Their combination of structural rigidity and dynamic flexibility leads to naturally unique property profiles and I would like to explore possibilities for their applications as functional materials in solid-state ionics, thermoelectrics, barocalorics and more—where dynamic disorder can be harnessed as a functional design feature.