Recent Development in Crystal Growth from High-Temperature Solutions

The growth of crystals from molten salt solutions or “fluxes” has historically been an empirical art which developed principally as a tool for mineral synthesis. The use of fluxes to grow crystals of technological interest began with the work of Remeika who grew barium titanate, BaTiO3, from molten potassium fluoride, KF [1], and ferrimagnetic spinels, MFe2O4, from molten lead oxide, PbO [2]. A major impetus to flux growth was the discovery that magnetic garnets, Ln3Fe5O12, could be grown from PbO [3], Bi2O3 [3], and PbO-PbF2 mixtures [4]. That work and Remeika’s discovery of the addition of boric oxide to PbO and Bi2O3 to improve their solvent power for the growth of many oxides set the stage for wide application of the flux method.