| 摘要 |
PURPOSE:To obtain a high-quality rutile single crystal free from sub-grain texture, by keeping the oxygen partial pressure in the growth atmosphere below a specific pressure, and growing the single crystal of TiO2 from the molten liquid, thereby developing only one kind of crystal phase. CONSTITUTION:A single crystal of TiO2 is made to grow from the molten liquid of TiO2 keeping the oxygen partial pressure in the atmosphere to <=3X10<-2>atm. There is no particular restriction in the crystal growth method, however, a floating zone process is preferable from the viewpoint of the contamination from the crucible, etc. The oxygen partial pressure in the crystal growth atmosphere can be maintained to <=3X10<-2>atm, e.g. by the high-temperature thermal equilibrium reaction or heat-decomposition reaction near the temperature of crystal growth, or by the use of gas emitting a specific amount of free oxygen, e.g. CO2, NOX, etc. Only one kind of a crystal phase can be crystallized by the above process, and a high-quality rutile crystal free from sub-grain texture can be prepared.
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