Hydroxyperovskites: Frustrated magnetism and hydrogen disorder

Hydroxide perovskites represent a rich class of materials that were recently demonstrated to host correlated proton disorder, similar to that known in hexagonal water ice. Many of these compounds host magnetic transition-metal ions. Of particular interest are so-called double hydroxyperovskites with a rock-salt–type arrangement of magnetic and nonmagnetic transition-metal ions on the B site, which realize a geometrically frustrated fcc magnetic sublattice. The theory of frustrated magnetism on the fcc lattice is a subject of intense current research, indicating that this magnetic model may hold great promises for the realization of quantum-disordered ground states known as spin liquids. However, experimental realizations of such lattices remain very limited. The high chemical tunability of hydroxide perovskites makes them an excellent platform for studying frustrated magnetism, yet the experimental characterization of their magnetic properties are lacking until now. For some double hydroxyperovskites containing 5d transition-metal ions even the crystal structure still awaits to be clarified.

We therefore intend to synthesize magnetic hydroxide perovskites and perform chemical, thermal and crystallographic characterization. This project is ideally suited for a student with a background in synthesis of inorganic materials, solid-state and structural chemistry and crystallography. In collaboration with physicists, in-depth study of their magnetic properties by thermodynamic measurements and neutron scattering are scheduled.