PRODUCTION OF GALLIUM SUBSTITUTION TYPE YIG SINGLE CRYSTAL FOR MICROWAVE

摘要

PURPOSE:To convert the Ga ion distributions in a single crystal from high temp. type to low temp. type by moving a Ga-contg. raw material bar combined with a seed crystal under application of centralized heat thereto to grow a single crystal, and heating said single crystal gently at specific temps. CONSTITUTION:A quartz tube 2 is located at the center enclosed by a bielliptical circular reflecting mirror 1 and the IR rays from halogen lamps 3 installed in focal parts are condensed at one place in the tube 2. A shaft 4 is provided in the tube 2, and a seed crystal 5 is placed thereon; further a raw material bar 6 of yttrium-iron type garnet contg. Ga is located in the upper part thereof. An after-heater 7 is mounted in such a way as to enclose the grown crystal. The single crystal right after the growing descends slowly in the heater 7, and is heat treated in an oxygen atmosphere of 1,500-800 deg.C and about =10-2kg/cm2 during the process thereof, whereby the distributions of the Ga in the single crystal are converted from high temp. type to low temp. type.