| abstract |
An α-sialon is offered which is represented by general formula: (M1) X (M2) Y (Si, Al) 12 (O, N) 16 (wherein M1 represents one or more elements selected from the group which consists of Li, Mg, Ca, Y and lanthanoid (except La and Ce) and M2 represents one or more elements selected from the group which consists of Ce, Pr, Eu, Tb, Yb and Er and wherein 0.3<X+Y<1.5 and 0<Y<0.7), the α-sialon containing from 30 ppm to 1% of fluorine as an impurity. By making primary particles of the α-sialon 1 to 10 μm in average particle size, an α-sialon phosphor can be obtained reproducibly, stably and in a large quantity. Especially, if containing 30 to 200 ppm of impurity fluorine, the α-sialon phosphor can exhibit an excellent emission characteristic as a white fluorescent matter. |