Process of preparing crystals of compounds and alloys

摘要

A liquid phase, which comprises either at least one of the constituents of the compound or alloy of which the crystal is to be prepared, or a foreign material, is fed continuously at its surface with the other constituent or constituents of this compound or alloy (or with all the constituents when the liquid phase comprises a foreign material). This liquid phase is subjected to two successive temperature gradients the first of which is slight and the second steep, so that the constituents are transported through the liquid phase and so that the crystallization of the compound or alloy takes place at the level of the second gradient. The liquid phase and the temperature gradients are displaced with respect to each other at a speed determined such that the composition of the liquid phase does not change and such that the crystallization always takes place at the same temperature.