The invention belongs to the field of luminescent materials. Disclosed are silicate luminescent materials doped with metal nano particles and preparation methods there for. The silicate luminescent materials doped with metal nano particles are represented by the chemical formula:MLn.sub.1-xSiO.sub.4:xRE,yA; wherein M is one or two elements selected from Li, Na and K; Ln is one or two elements selected from Y, Sc, La and Lu; A is a metal nano particle selected from Ag, Au, Pt, Pd and Cu; RE is one or two ions selected from Eu, Gd, Tb, Tm, Sm, Ce and Dy; 0<x0.1; 0<y0.005. When silicate luminescent materials doped with metal nano particles of the invention are excitated by electron beam, they have higher luminescent efficiency. The luminescent materials are good to be used in field emission light source devices.

Provided is a phosphor including: a host material expressed by a general formula (Ca1-xMex)a(Ce1-y-zLayPrz)bSicXd (0.5b/a7, 1.5c/(a+b)3.5, 4d/(a+b)6, 0x0.5, 0y<1, 0z0.5, and 0y+z<1, where X is at least one element selected from N, O, F, and Cl); and at least one activator that is selected from Mn, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Ho, Er, Tm, and is solid-solutioned in the host material, wherein Me is at least one element selected from Ba, Mg, Sr, Mn, and Zn, and the host material includes, as a main phase, a phase that exhibits a diffraction peak having a relative intensity of 5% or more in ranges of Bragg's angles (2) of 10.68-11.41, 18.52-19.46, 31.21-31.58, 31.61-32.20, and 36.81-37.49 of an X-ray diffraction pattern when a relative intensity of a diffraction peak having the strongest intensity is set to 100% in the X-ray powder diffraction pattern.

To provide a phosphor being chemically-thermally stable and having high luminous intensity if combined with LED of not exceeding 470 nm. A phosphor of the present invention includes: inorganic compound including: a crystal represented by Li.sub.1Ba.sub.2Al.sub.1Si.sub.7N.sub.12; a crystal represented by (Li, A).sub.3(D, E).sub.8X.sub.12; and an inorganic crystal having the same crystal structure as the crystal represented by Li.sub.1Ba.sub.2Al.sub.1Si.sub.7N.sub.12; and a solid-solution crystal thereof, which contains Li, A, D, E, and X elements (A represents at least one selected from Mg, Ca, Sr, Ba, Sc, Y and La; D represents at least one selected from Si, Ge, Sn, Ti, Zr and Hf; E represents at least one selected from B, Al, Ga and In; and X represents at least one selected from O, N and F), wherein M element (M represents at least one selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb) is solid-solved into each.