Advances in High-Pressure Floating Zone Crystal Growth

The development of new quantum materials is often catalyzed by advances in crystal growth techniques that allow for new compounds to be stabilized in bulk single crystal form. Either through enabling the growth of previously inaccessible compounds, allowing the resolution of hidden anisotropies, or through facilitating access to ultrahigh purity material, bulk crystal growth is often an engine for discovery in quantum materials. Floating zone crystal growth is one technique that is particularly well suited for quantum materials due to its high-purity, crucible-free growth geometry and due to its ability to grow large-volume single crystals of both congruent and incongruently melting compounds. However, one of the historical limitations of the floating zone technique is the constraint of relatively low reactive and blanketing gas pressures in the growth chamber. This often precludes the growth of compounds whose desired oxidation states or phase stabilities require high partial pressures of reactive gases to form or of compounds whose volatility prohibits growth under low blanketing gas pressures. In this talk, I will present some of the recent advances in pushing the growth pressures of floating zone optical furnaces upward. I will highlight some of the new tools developed in our group and illustrate the impact high-pressure floating zone growth can have on the stabilization and understanding of various quantum materials.