摘要 |
There is provided a method for preparing a highly accelerated-phosphorescent phosphor whose erasability and after-image characteristic are both improved. Phosphor materials are mixed together to obtain a mixture, and the mixture of phosphor materials is fired in a furnace having a firing region whose capacity is 2 to 500 L per kilogram of the mixture, at a temperature of 550 to 1000° C. while introducing 1 to 200 ml of oxygen in volume at room temperature per liter capacity of the firing region in the furnace, to thereby prepare a phosphor represented by the following compositional formula (I):wherein, MIIa is alkaline earth metal such as Sr, Ca or Mg; MI is alkali metal such as Li, Na or K; MIII is Al, Ga or In; X is Cl, Br or I; Ln is rare earth element such as Ce, Eu or the like; A is a metallic oxide such as Al2O3; and a, b, c, d and x are numerical values within the ranges of 0<=a<=0.3, 0<b<=2, 0<=c<=2, 5x10-5<=d<=0.5, and 0<x<=0.2.
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