Phosphor

Abstract

A rare earth element activated complex halide phosphor represented by the formula BaF.sub.2.aBaX.sub.2.bMgF.sub.2.cMe.sup.I F.dMe.sup.II F.sub.2.eMe.sup.III F.sub.3 :fLn wherein X is at least one halogen selected from the group consisting of Cl, Br and I, Me.sup.I is at least one alkali metal selected from the group consisting of Li and Na, Me.sup.II is at least one divalent metal selected from the group consisting of Be, Ca and Sr, Me.sup.III is at least one trivalent metal selected from the group consisting of Al, Ga, Y and La, Ln is at least one rare earth element selected from the group consisting of Eu, Ce and Tb, and a, b, c, d, e and f are numbers satisfying the conditions of 0.90.ltoreq.a.ltoreq.1.05, 0.ltoreq.b.ltoreq.1.2, 0.ltoreq.c.ltoreq.0.9, 0.ltoreq.d.ltoreq.1.2, 0.ltoreq.e.ltoreq.0.03, 10.sup.-6 .ltoreq.f.ltoreq.0.03 and c+d+e.noteq.0. The phosphor emits light of high luminance when stimulated by light of wavelength ranging from 450 to 800 nm after exposure to ionizing radiations, ultraviolet rays, cathode rays, or the like. Further, the phosphor emits thermoluminescent light of high luminance when heated after exposure to ionizing radiations, ultraviolet rays, cathode rays, or the like.

Dependencies are inferred from the claim text.