High-Pressure Laser Floating Zone Furnace*

The floating zone technique is one of the most established methods in growing single crystals for materials research applications, due to its propensity to produce large, extremely high quality specimens. However, limitations in the ultimate pressures of growth atmospheres in standard furnace designs renders many compounds not suitable for crystal growth employing the floating zone technique, either due to excessive volatility or metastability. Here we demonstrate a high pressure laser floating zone system which pushes the envelope of processing pressure for this technique. Focused laser light allows for extremely sharp heating gradients, uniform radial heating profiles and high processing temperatures. In turn this allows for the implementation of a high strength metal growth chamber, allowing for greatly enhanced processing pressures. We demonstrate successful single crystal growths of a range of oxide compounds up to 10 kpsi applied gas pressures, a more than two-fold increase in processing pressures compared to commercially available floating zone systems.