Phosphor and light emitting device using the same

A light emitting device comprising a light source and a phosphor which is excited by light emitted from the light source and has a composition represented by the following general formula:

• (M11−yRy)aMgM2bM3cOa+2b+(3/2)cX2
• wherein M1 is at least one element selected from the group consisting of Ca, Sr, Ba, Zn and Mn, M2 is at least one element selected from the group consisting of Si, Ge and Sn, M3 is at least one element selected from the group consisting of B, Al, Ga and In, X is at least one element selected from the group consisting of F, Cl, Br and I, R is at least one element selected from the group consisting of rare earth elements with Eu being inevitable element, and y, a, b and c satisfy the following relationships of 0.0001≦y≦0.3, 8.5≦a<9.5, 3.0≦b<5.0 and 0≦c<1.0.

A phosphor having a composition represented by the following general formula:

• (M11−yRy)aMgM2bM3cOa+2b+(3/2)cX2
• wherein M1 is at least one element selected from the group consisting of Ca, Sr, Ba, Zn and Mn, M2 is at least one element selected from the group consisting of Si, Ge and Sn, M3 is at least one element selected from the group consisting of B, Al, Ga and In, X is at least one element selected from the group consisting of rare earth elements with Eu being inevitable element, and y, a, b and c satisfy the following relationships of 0.0001≦y≦0.3, a=7.5, 3.0<b<5.0 and 0≦c<1.0.