Patent GB-949233-A (GB)
Title: A fusion process for producing a compound or an alloy in crystalline form
IPC: C01G1/00
Filed: 1961-06-05
Abstract: <PICT:0949233/C1/1> A compound or an alloy in crystalline form, e.g. containing zinc or cadmium, with at least one readily volatile component such as arsenic or phosphorus and at least one sparingly volatile component such as indium, gallium, tin or germanium, is produced by sealing the components in a vessel, first heating the bottom thereof sufficiently to form a melt of the sparingly volatile component(s) at the bottom of the vessel while the readily volatile component(s) condense(s) at the top, then gradually heating the remainder of the vessel, e.g. at least to the same temperature, so that a vapour phase consisting of at least one readily volatile component is formed over the melt and becomes dissolved therein, prior to solidifying the melt either as oriented or unoriented crystals. For example, a quartz vessel 21 may be charged with the components and sealed in a vacuum or protective gas atmosphere such as argon, and its bottom inserted into a tubular furnace as shown in Fig. 2, where it is heated to melt the sparingly volatile components preferably initially prepared as an alloy, the readily volatile component 23 condensing and being preferably retained by a annular container 22 at the top.  After thorough mixing by shaking preferably in the horizontal position, the vessel may be granually withdrawn from the furnace for growing a single crystal.  The process is suitable for the production of solid solutions of the type <FORM:0949233/C1/1> <FORM:0949233/C1/2> where numerals denote the Groups of the Periodic System, e.g. alloys consisting of (Cd0.4, Pb0.2, Sb0.4) As and (Ag0.4, Pb0.2, Sb0.4) Te respectively, the subscripts being in atomic weights. Examples of compounds produced are Cv3P and In (P0.2 As0.8) where the furnace was maintained at 1000 DEG  C. and 1100 DEG  C. respectively. Specification 786,818 is referred to.ALSO:A compound or an alloy in crystalline form, e.g. containing zinc or cadmium, with at least one readily volatile component such as arsenic or phosphorus and at least one sparingly volatile component such as indium, gallium, tin or germanium, is produced by sealing the components in a vessel, first heating the bottom thereof sufficiently to form a melt of the sparingly volatile component(s) at the bottom of the vessel while the readily volatile component(s) condense(s) at the top, then gradually heating the remainder of the vessel, e.g. at least to the same temperature, so that a vapour phase consisting of at least one readily volatile component is formed over the melt and becomes dissolved therein, prior to solidifying the melt <PICT:0949233/C3/1> either as oriented or unoriented crystals.  For example, a quartz vessel 21 may be charged with the components and sealed in a vacuum or protective gas atmosphere such as argon, and its bottom inserted into a tubular furnace as shown in Fig. 2 where it is heated to melt the sparingly volatile components preferably initially prepared as an alloy, the readily volatile component 23 condensing and being preferably retained by an annular container 22 at the top.  After thorough mixing by shaking preferably in the horizontal position, the vessel may be gradually withdrawn from the furnace for growing a single crystal.  The process is suitable for the production of solid solutions of the types (AII BIII CIV) DV and x/2  1-x x/2 (AI BIV CV) DVI where numerals denote x/2  1-x  x/2 the Groups of the Periodic System, e.g. alloys consisting of (Cd0.4 Pb0.2 Sb0.4) As and (Ag0.4 Pb0.2 Sb0.4) Te respectively, the subscripts being in atomic weights. Examples of compounds produced are Cu3 P and In (P0.2 As0.8) where the furnace was maintained at 1000  DEG C. and 1100  DEG C. respectively. Specification 786,818 is referred to.