High-Pressure Laser Floating Zone Furnace

TL;DR

This paper introduces a high-pressure laser floating zone furnace that enables crystal growth at pressures up to 1000 bar, surpassing traditional systems and expanding the range of materials that can be processed.

Contribution

The development of a novel laser-based floating zone system allowing high-pressure growth up to 1000 bar, overcoming limitations of conventional mirror-based furnaces.

Findings

Achieved crystal growth at pressures up to 675 bar.

Demonstrated growth of complex oxides at high pressures.

Enhanced chamber strength enables higher processing pressures.

Abstract

The floating zone technique is a well-established single crystal growth method in materials research, able to produce volumetrically large specimens with extremely high purities. However, traditional furnace designs have relied on heating from high-powered bulb sources in combination with parabolic mirrors, and hence are constrained to transparent growth chambers with large solid angles of optical access. This results in a stark limitation on achievable processing gas pressures, and in turn renders a range of compounds unsuitable for crystal growth by the floating zone technique, either due to excessive volatility or due to metastability. Here, we demonstrate a novel high-pressure laser-based floating zone system (HP-LFZ). The use of lasers for heating allows implementation of a high-strength metal growth chamber, permitting greatly enhanced processing pressures over conventional mirror-based designs, with the current design allowing for pressures up to 1000 bar. We demonstrate a series of example single crystal growths using this design in pressures up to 675 bar, a significant increase over processing pressures attainable in commercially available floating zone systems. The general utility of the HP-LFZ is also illustrated via growths of a range of complex oxides.