Abstract: A magnetic powder of an Sm—Fe—N alloy, which has a mean particle diameter of 0.5 to 10 &mgr;m, and either an average acicularity of 75% or above or an average sphericity of 78% or above. The powder exhibits an extremely high residual magnetization and an extremely high coercive force, since particles characterized by the above acicularity or sphericity have particle diameters approximately equal to that of the single domain particle and nearly spherical particle shapes. The powder can be produced by preparing an Sm—Fe oxide by firing a coprecipitate corresponding to the oxide, mixing the obtained oxide with metallic calcium and subjecting the mixture to reduction/diffusion and nitriding successively.

Abstract: A magnetic powder of an Sm—Fe—N alloy, which has a mean particle diameter of 0.5 to 10 &mgr;m, and either an average acicularity of 75% or above or an average sphericity of 78% or above. The powder exhibits an extremely high residual magnetization and an extremely high coercive force, since particles characterized by the above acicularity or sphericity have particle diameters approximately equal to that of the single domain particle and nearly spherical particle shapes. The powder can be produced by preparing an Sm—Fe oxide by firing a coprecipitate corresponding to the oxide, mixing the obtained oxide with metallic calcium and subjecting the mixture to reduction/diffusion and nitriding successively.

Abstract: A magnetic powder of an Sm—Fe—N alloy, which has a mean particle diameter of 0.5 to 10 &mgr;m, and either an average acicularity of 75% or above or an average sphericity of 78% or above. The powder exhibits an extremely high residual magnetization and an extremely high coercive force, since particles characterized by the above acicularity or sphericity have particle diameters approximately equal to that of the single domain particle and nearly spherical particle shapes. The powder can be produced by preparing an Sm—Fe oxide by firing a coprecipitate corresponding to the oxide, mixing the obtained oxide with metallic calcium and subjecting the mixture to reduction/diffusion and nitriding successively.

Abstract: An afterglow lamp has a light emitting section for converting electric energy to optical energy. A fluorescent layer is excited to emit-light by the light emitting section and is represented by the general formula (M.sub.1-p-q, Eu.sub.p Q.sub.q)O.multidot.n(Al.sub.1-m B.sub.m).sub.2 O.sub.3 .multidot.kP .sub.2 O.sub.5 .multidot..alpha.X. The values of p, q, n, m, k, .alpha. and .alpha./n are in the ranges 0.0001.ltoreq.p.ltoreq.0.5, 0.0001.ltoreq.q.ltoreq.0.5, 0.5.ltoreq.n.ltoreq.3.0, O.ltoreq.m.ltoreq.0.5, O.ltoreq.k.ltoreq.0.2, O.ltoreq..alpha..ltoreq.0.5, and O.ltoreq..alpha./n.ltoreq.0.4. M is at least one selected from a group of divalent metals including Mg; Q is a coactivator and at least one selected from a group including Mn, Zr, Nb, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; and X is at least one selected from halogen elements.

Abstract: A phosphor composition and a lamp having a phosphor film formed of the composition. The composition contains red, green and blue luminescence components. The blue component emits blue light by the excitation of 253.7-nm ultraviolet light. It has a main luminescence peak wavelength of 460 to 510 nm, and a half width of the main peak of a luminescence spectrum of not less than 50 nm. The color coordinates of the luminescence spectrum of the blue component falls within a range of 0.15.ltoreq.x.ltoreq.0.30 and of 0.25.ltoreq.y.ltoreq.0.40 based on the CIE 1931 standard chromaticity diagram. The blue component has a spectral reflectance of not less 80% at 380 to 500 nm, assuming that a spectral reflectance of a smoked magnesium oxide film is 100%.

Abstract: A green light-emitting fluorescent material prepared from terbium-activated lanthanum cerium orthophosphate expressed by the structural formula:La.sub.x Tb.sub.y Ce.sub.z PO.sub.4where:x+y+z=10.05<x<0.350.05<y<0.30.6<z<0.9and a fluorescent lamp comprising said green light-emitting fluorescent material used alone or in combination with any other form of fluorescent material.