| dc.description |
THIS communication describes a method of preparing colourless, extremely pure crystals of α-silicon carbide by a modified Lely process in a high-vacuum, high-temperature furnace from silicon of a purity sufficient for semi-conductors and pure graphite. The temperature at which the main reaction occurs, in the course of which the crystals are formed, is 2,800° C. The energy gap, determined according to the method devised by Macfarlane and Roberts, is 2.96 eV. Crystal wafers 100â 200µ thick with fresh surfaces exhibited a transmission factor of 80â 85 per cent at the characteristic wave-length of 2â 4µ. |
