abstract |
Provided is a β-type SiAlON that comprises Eu, is represented by the general formula Si 6-z Al z O z N 8-z , and is a β-type SiAlON in which an a-axis lattice constant and chromaticity x of CIE chromaticity satisfy formula 1.na-axis lattice constant (Å) ≤ 0.1075 × chromaticity x + 7.5742 (formula 1)nFurthermore, the β-type SiAlON preferably has an average grain diameter (D50) (μm) / BET diameter (μm) as calculated by formula 2 and formula 3 that is less than 1.9.nBET diameter (μm) = 6 ÷ (3.22 × BET value (m 2 /g)) (formula 2)nD50 (μm) / BET diameter (μm) < 1.9 (formula 3) |