8 cm thick layer as from the end of this operation a square tungsten frame with 5 cm edges is rapidly immersed in the silicon bath through the molten eutectic layer after holding for approximately 3 minutes the frame is removed from the silicon at a speed of 1 cm minute a silicon diaphragm is then entrained by the frame and when the latter is removed from the silicon bath but still in the molten eutectic medium solidification starts by oriented programmed cooling the frame and the solidified diaphragm are then removed from the bath a second operation can then commence by remelting the silicon mass a pure graphite crucible containing the eutectic caf 2 mgf 2 and silicon in an adequate quantity corresponding to the desired plate is heated to beyond the melting point of the silicon i e approximately 1450 u00b0 c the silicon then systematically collects in the form of a single drop under the action of the surface active properties of the agents present this drop is positioned at the bottom of the graphite crucible a tungsten frame having an extensible shape but with a reduced configuration is then introduced until it is in contact with the silicon drop fig5 by wetting the silicon is attached to the close together posts of the frame and stabilizes in a few minutes the development of the surface of the frame can then commence by a vertical movement of its lower post 7 at a speed of approximately 1 cm per minute when the surface is developed the attached silicon diaphragm is then solidified in the liquid eutectic before being removed as in example 2 the silicon drop is formed in a bath and in this case its density is higher than that of the.