METHOD OF THERMAL TREATMENT OF CORUNDUM ACTIVATED MONOCRYSTALS AND ARTICLES MADE OF THE MONOCRYSTALS Russian patent published in 1994 - IPC

FIELD: monocrystals. SUBSTANCE: treatment is carried out by annealing under temperature of no less than 1750 C in oxygen and hydrogen atmosphere. Monocrystals with concentration of activator of no more than 0.2 weight % are subjected to annealing first in oxidizing atmosphere with partial oxygen pressure 1·10³-1·10⁵ Pa, then - in hydrogen. Annealing in oxidizing medium is exercised within time period of τ₁=x²/8D and in hydrogen - within 5 hours. "X" in above formula means minimum size of monocrystals in cm, D=2·10^-6 cm²/c - diffusion factor of anion vacancies in corundum monocrystals. EFFECT: method increases beam strength of corundum monocrystals. 2 cl, 1 tbl, 1 ex