Patent ID: 6929693

Claim:
A process for manufacturing a tetragonal single crystal ( 1 , 11 ) by growth from solution, from an approximately parallelepipedal single-crystal seed ( 2 , 22 ), the edges of the faces of which have lengths of AG 1 , AG 2 and AG 3 , which is supported on a platform ( 50 ) immersed in the solution ( 60 ) and set in rotation, said single crystal ( 1 , 11 ) having growth rates (Vx, Vy, Vz) of the same order of magnitude along the principal crystallographic axes (X, Y, Z), characterized in that it comprises at least the following steps: the seed is cut from a single crystal so that at least one length of the edges, AG 3 , of the seed is less than or equal to one fifth of the greatest length of the edges of the seed, AG 1 , and so that at least one length of the edges of the seed is greater than or equal to 25 mm, the seed is positioned on the platform ( 50 ) in the desired orientation; and the platform ( 50 ) with the seed ( 2 , 22 ) is put into a crystallizer ( 70 ) containing the solution ( 60 ) and then set in rotation, in order to carry out the growth of the single crystal ( 1 , 11 ).