Patent ID: 9115311
Filing Date: 2015-08-25
Classification: C04B,C09K

Abstract:
1. An oxide ceramic fluorescent material comprising a transparent polycrystalline ceramic sintered body of at least one oxide selected from the group consisting of Y 3 Al 5 O 12 , Lu 3 Al 5 O 12 , (Y,Lu) 3 Al 5 O 12 , (Y,Gd) 3 Al 5 O 12 , and Al 2 O 3 in which at least one rare earth element as a fluorescent activator selected from the group consisting of Ce, Eu and Tb has been diffused into the polycrystalline ceramic sintered body, wherein the concentration of the rare earth element is 1% by weight at a depth in the range of 50 μm to 600 μm deep as measured from the sintered body surface and at least 1% by weight at any position nearer to the sintered body surface than said depth.