Phosphor material and light-emitting device
A phosphor material according to an embodiment of the present disclosure contains a major component represented by the formula A 2-v-w-x-y B v Ln w Eu x Sm y M 2-z D z O 8 , where A is one or more elements selected from the group consisting of alkaline-earth metal elements; B is one or more elements selected from the group consisting of alkali metal elements; Ln is one or more elements selected from the group consisting of rare-earth elements other than Eu and Sm; M is one or more elements selected from the group consisting of W and Mo; D is one or more elements selected from the group consisting of Nb and Ta; and v, w, x, y, and z satisfy the inequalities 0≦v≦0.5, 0.15≦x+y≦0.7, 0≦y≦0.05, and 0<z≦1.7 and the equation w+x+y=v+z.
1. A phosphor material containing a major component represented by the formula A 2-v-w-x-y B v Ln w Eu x Sm y M 2-z D z O 8 , where A is one or more elements selected from the group consisting of alkaline-earth metal elements; B is one or more elements selected from the group consisting of alkali metal elements; Ln is one or more elements selected from the group consisting of rare-earth elements other than Eu and Sm; M is one or more elements selected from the group consisting of W and Mo; D is one or more elements selected from the group consisting of Nb and Ta; and v, w, x, y, and z satisfy the inequalities 0≦v≦0.5, 0.15≦x+y≦0.7, 0≦y≦0.05, and 0<z≦1.7 and the equation w+x+y=v+z.
2. The phosphor material according to claim 1 , further containing 0.1% to 1.0% by weight of one or more elements selected from the group consisting of Li 2 O, Na 2 O, K 2 O, LiF, MgF 2 , and ZnF 2 as one or more minor components.
3. The phosphor material according to claim 1 , wherein v satisfies the inequalities 0<v≦0.33, and z satisfies the inequalities 0.5≦z≦1.5.
4. The phosphor material according to claim 1 , wherein y satisfies the inequality 0.01≦y≦0.05.
5. The phosphor material according to claim 1 , wherein A is Ca, B is one or more elements selected from the group consisting of Li and Na, Ln is one or more elements selected from the group consisting of Gd and Y, M is W, and D is Nb.
6. The phosphor material according to claim 1 , being a sintered body.
7. A light-emitting device comprising:
an excitation light source; and
the phosphor material according to claim 1 , wherein the phosphor material absorbs excitation light emitted from the excitation light source to emit light.