コランダム(A1₂O₃)のPbO-B₂O₃系フラックスへの溶解度と単結晶の育成

抄録

Solubilities of Al₂O₃ in PbO-B₂O₃ flux were investigated in various mole fractions of B₂O₃ at 1, 300°C, 975°C and 600°C, and growth condi tion of corundum crystal in the flux were studied. Heat of solution and related thermodynamic values were calculated corresponding to the B₂O₃mole fractions. Two regions may be distinguished concerning with the changes of these thermodynamic values versus B₂O₃ mole fractions ; one region is more than 0.2 mole fraction of B₂O₃ and the other is less than 0.2 mole fraction. It is concluded that the solubility is significantly affected by the chemical interaction between solute and solvent. Moreover, a Co-doped corundum was synthesized by the same flux growth technique, where the crystal formed a pale green-colored transparent and thin plate containing 0.06 wt.% of Co (III) . Lattice para meters of the Co-doped corundum are as follows.a=4.757±0.001Åc=12.989±0.010Å Since these values are almost the same as those of the corundum with out any dopants, Co atom seems to substitutionally occupy the Al site in its crystal structure.