500 A METHOD FOR THE PREPARATION OF DOPED GARNET STRUCTURE SINGLE CRYSTALS WITH DIAMETERS OF UP TO 500 MM

摘要

The preparation of a lutetium and yttrium aluminate single crystal doped with rare earth oxides and transition elements is characterized by the processing of an oxide mixture sinter which is completely melted and homogenized for a period of more than one hour. The single crystal seed has a minimum dimension of 8 x 8 mm and a length of 100 mm. The crystal growth rate and the widening of the crystal cone are uniformly maintained to a diameter of 80% or more of the crucible diameter of at least 100 mm at an angle of 60 DEG or more from the crystal axis. Thereafter, its diameter is continuously maintained by temperature control at the crystal / melt interface and by crystal pull and rotational speed. Completion of the process occurs by separating the crystals from the melt, but the crystals are subsequently placed in the zone where the crystals grow inside the crucible, and the final tempering of the crystals also occurs.