Growth in solution in a float zone of crystals of a compound or an alloy

A process for the production of a crystal of a material with non-congruent melting, made from at least one first element and a second element, with the process comprising the following stages:

• Placing, in a vertical alignment, and maintaining under a neutral atmosphere or under vacuum, a bar of the first element gripped between a lower bar and an upper bar made out of said material;
• Transforming the bar of the first element into a floating zone by heating to a temperature that avoids the evaporation of the first element, the heating being obtained by heating means that provides a temperature gradient in the floating zone so that one of the faces of either the lower bar or the upper bar, which are in contact with the bar of the first element, appears as a cold face;
• and
• Contra-rotating the lower and uppers bars around the alignment axis and moving the whole bar assembly along the alignment axis in relation to the heating means in order to move the cold face away and obtain said crystal, on the cold face, by growth in solution.