The 2DCC Double Crucible Vertical Bridgman (DCVB) furnace is a custom-designed Bridgman furnace installed in December 2022, dedicated to bulk crystal growth under vacuum or high-pressure inert atmosphere. This apparatus is the first Bridgman furnace in the world to be equipped with a double-crucible geometry as well as a high-pressure chamber. The implementation enables the growth of homogeneous crystals even if the target material melts incongruently and precise control of chemical composition.

 

The DCVB furnace utilizes two crucibles for distinct purposes. The one located at the bottom is for growing crystals, whereas the top one is for continuously feeding source materials to the growth crucible, compensating for the otherwise unavoidable compositional fluctuation of the melt. Maintaining the desired melt composition throughout the growth run allows for obtaining bulk crystals (1) of incongruent melting materials, (2) with intended chemical composition, and (3) of homogeneity. In addition, the volatilization of elements such as chalcogens is suppressed by applying high pressure, which further hampers the appearance of off-stoichiometric phases.