Patent ID: 6361714
Filing Date: 2002-03-26
Classification: C09K

Abstract:
A method of preparing a barium fluorohalide phosphor represented by the formula (Ba1âˆ’a, MIIa) FX.bMI.cMIII.dA: xLn, wherein MIIa is at least one alkaline earth metal selected from the group consisting of Sr, Ca and Mg; MI is an alkali metal compound comprising at least one metal selected from the group consisting of Li, Na, K, Rb and Cs; MIII is a trivalent metal compound comprising at least one metal selected from the group consisting of Al, Ga, In, Tl, Sc, Y, Cd and Lu, except for Al2O3; X is at least one halogen selected from the group consisting of Cl, Br and I; Ln is at least one rare earth element selected from the group consisting of Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Nd, Er, Tm and Yb; A is at least one metal oxide selected from the group consisting of Al2O3, SiO2 and ZrO2; and a, b, c, d and x are 0&lE;a&lE;0.3, 0(a) preparing a mixture of phosphor materials; (b) firing the mixture of phosphor materials by the substeps: (i) burning the mixture of phosphor materials in an atmosphere at a substantially constant temperature; and (ii) removing the atmosphere and replacing with a different atmosphere while maintaining the substantially constant temperature; and (c) annealing the mixture of phosphor materials.