| abstract |
The present invention is a material of the formula M 1-y A 1 + x Si 4-x N 7-x-2y O x + 2y : RE, where M comprises Ba, Sr, Ca, Mg and mixtures thereof Selected from the group, A is selected from the group comprising Al, Ga, B and mixtures thereof, RE is selected from the group comprising rare earth metals, Y, La, Sc and mixtures thereof, x is 0 or more and 1 The following relates to an improved red-emitting fluorescent material, and wherein y is from 0 to 0.2. This material is believed to crystallize with a novel structural type containing two separate lattice sites for rare earth metal uptake. |