Light wavelength conversion member and light-emitting device
In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al 2 O 3 crystal grains and crystal grains represented by formula X 3 Al 5 O 12 :Ce. In the optical wavelength conversion member 9 , atoms of element X are present also in an Al 2 O 3 crystal grain adjacent to the interface between the Al 2 O 3 crystal grain and an X 3 Al 5 O 12 :Ce crystal grain.
1. An optical wavelength conversion member comprising a polycrystalline ceramic sintered body containing, as main components, Al 2 O 3 crystal grains and crystal grains represented by formula X 3 Al 5 O 12 :Ce, wherein
X of X 3 Al 5 O 12 :Ce is at least one element selected from the following element group:
X: lanthanoids (except for Ce), Y, and Sc; and
atoms of element X are present also in an Al 2 O 3 crystal grain adjacent to the interface between the Al 2 O 3 crystal grain and an X 3 Al 5 O 12 :Ce crystal grain, wherein said atoms of element X are present at depths of 1 nm to 20 nm as measured from the surface of the Al 2 O 3 crystal grain adjacent to the interface.
2. A light-emitting device comprising an optical wavelength conversion member as recited in claim 1 and a light-emitting element.