Sintered body
A sintered material is provided having a phase of a compound at least containing a rare earth element and fluorine, the sintered material having an L* value of 70 or more in the L*a*b* color space. The crystal grains of the sintered material preferably has an average grain size of 10 μm or less. The sintered material preferably has a relative density of 95% or more. The sintered material preferably has a three-point flexural strength of 100 MPa or more. The sintered material preferably contains no oxygen, or preferably has an oxygen content of 13% by mass or less when containing oxygen. The compound is preferably rare earth element fluoride or oxyfluoride.
1 . A sintered material having a phase of rare earth element oxyfluoride as a main phase, wherein
the sintered material has properties including:
an L* value of 75 or more and less than 90, an a* value of −1 to 3, and a b* value of −1 to 3 in an L*a*b* color space;
a three-point flexural strength of 110 MPa or more; and
a relative density of 98% or more, and
crystal grains of the sintered material have an average grain size of 10 μm or less.
2 . The sintered material as set forth in claim 1 , wherein
the sintered material contains oxygen and has an oxygen content of 13% by mass or less.
3 . The sintered material as set forth in claim 1 , for use in a halogen-containing dry etching gas atmosphere.
4 . The sintered material as set forth in claim 1 , wherein
the sintered material has a phase of rare earth element fluoride as a sub phase.
5 . The sintered material as set forth in claim 4 , wherein
a peak height of a peak assigned to a (020) plane of the rare earth element fluoride is from 5 to 70%, based on a peak height of a main peak assigned to the phase of the rare earth element oxyfluoride.
6 . The sintered material as set forth in claim 1 , wherein the rare earth element oxyfluoride is represented by LnO x F y , where 0.3≤x≤1.7 and 0.1≤y≤1.9, and
the sintered material has a rare earth element fluoride that is represented by LnF 3 .
7 . The sintered material as set forth in claim 1 , wherein
the three-point flexural strength of the sintered material is 500 MPa or less.
8 . The sintered material as set forth in claim 1 , wherein
relative to a main peak assigned to a phase of the rare earth oxyfluoride, a peak height of a largest peak attributable to a component in the sintered material other than a compound containing Ln and F in the sintered material is 10% or less.
9 . The sintered material as set forth in claim 1 , wherein
the average crystal grain size is 5 μm or less.