| 摘要 |
PROBLEM TO BE SOLVED: To obtain a luminous phosphor activated with bivalent europium, having a specific chemical compositional formula, thus attaining long afterglow time/high afterglow luminance compared to conventional silicate-based luminous phosphors, presenting diversified luminescent colors ranging from blue to yellowish green colors, therefore useful for e.g. night signs. SOLUTION: This luminous phosphor is such one as to be activated with bivalent europium and have a chemical composition of the formula (R is at least one element selected from the group consisting of Ca, Sr and Ba; M is a coactivator, being at least one element selected from the group consisting of Nb, Zr, Bi, Mn, Sn, In, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y; 0.4<=(a)<=0.9; 0.00001<=b<=0.30; 0.25<=c <=1.5; 0.00001<=d<=0.2; 0.00001<=e<=0.2; 0<=x<1.0; 0<=y< 1.0). This luminous phosphor is obtained by the following process: appropriate amounts of respective specified stocks are weighed, mixed together, put into an alumina crucible, and then burned at 950-1,500 deg.C for 1-12 h in a reductive atmosphere.
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