| 摘要 |
PROBLEM TO BE SOLVED: To produce an yttrium oxide sintered body having a high sintered density and high transparency. SOLUTION: This method for producing a transparent yttrium sintered body comprises adding a basic agent to a solution containing an yttrium salt in a concentration of 0.02-2 mole/liter at a temperature of <30 deg.C to produce yttrium hydroxide comprising agglomerates which each comprises many <=20 nm thick flaky particles agglomerated in a state wherein the table surfaces and the end surfaces are jointed to each other in a card-house structure and which each has a diameter of >=0.5μm, adding a sulfate ion-containing compound in an amount corresponding to 10<-3> to 1 fold mole of the sulfate ion that of the yttrium ion to the yttrium hydroxide so that the pH of the mixture is >=5 at the finish point of the addition, calcining the mixture at >=900 deg.C to form yttrium oxide powder having an average primary particle diameter of 30-500 nm, molding the obtained yttrium oxide particles, and sintering the molded product at a temperature of 1,500-2,000 deg.C in an atmosphere in which the total partial pressure of one or more kinds of atoms substantially not diffused in the yttrium oxide, such as nitrogen atom or argon atom is <=1/3 atm.
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