| abstract |
The present invention provides a method for producing transparent ceramics comprising a Tb-based composite oxide that improves diffuse transmittance in the visible region and functions as a magneto-optical element in a wide wavelength region from visible to the near infrared region. SOLUTION: The molar ratio of terbium oxide is 40 mol% or more, the other rare earth oxide is the remaining rare earth oxide as a main component, and the sintering aid is at least selected from group 2 elements and group 4 elements. After forming a molded body using raw material powder containing an oxide of one element, the molded body is heated to a sintering temperature T (1300 ° C. ≦ T ≦ 1650 ° C.) and sintered to a predetermined temperature from room temperature. The temperature increase rate up to T1 (1200 ° C. ≦ T1 ≦ T) is set to 100 ° C./h or more, and when the temperature is further increased from the predetermined temperature T1, the temperature increase rate is set to 1 ° C./h or more and 95 ° C./h or less. Sintering is performed by heating, and then HIP is performed at 1300 ° C. or more and 1650 ° C. or less to obtain a transparent ceramic made of a composite oxide sintered body having a crystal grain size of 0.5 μm or more and 2 μm or less. [Selection] Figure 1 |