| 摘要 |
PURPOSE:To obtain grown crystal of high purity by retarding decomposition of carbonate by applying higher gaseous CO2 pressure than equilibrium gaseous CO2 pressure to a soln. consisting of alkali earth metal carbonate and an oxide and allowing the oxide to grow in the liquid phase utilizing the soln. as solvent. CONSTITUTION:A substrate 2 for single crystal is placed on an end of a crucible 1 consisting of sintered BaTiO3, and BaCO3, powder 3 is arranged to another end. The crucible 1 is inclined in one direction under ca. 2atm CO2 pressure and the crucible is heated at about 1,300 deg.C to decompose a part of BaCO3 and a soln. contg. BaCO3 and BaO is formed. The wall of the crucible 1 is dissolved in the solvent to form satd. soln. 4 contg. BaTiO3 as solute. Then, the crucible 1 is inclined to the reverse direction to cover the substrate for the single crystal 2 with the satd. soln., and the temp. of the crucible is lowered slowly. Thereafter, the gaseous CO2 pressure is reduced to <=1atm, and residual solvent is converted to BaO, and BaO is removed by washing with water. Thus, the aimed grown crystal is obtd. |
