Annealed alkaline earth metal fluorohalide storage phosphor, preparation method, and radiation image storage panel

US5549843A · kind A · utility

Assignee

• EASTMAN KODAK COMPANY · US

Inventors

• Kyle E. Smith · Victor, US
• Joseph F. Bringley · Rochester, US
• Patrick M. Lambert · Rochester, US
• David P. Trauernicht · Rochester, US
• Philip S. Bryan · Webster, US
• Paul M. Hoderlein · Rochester, US
• Andrea M. Hyde · Hamlin, US

Key dates

• Filing date: Nov 21, 1991
• Grant date: Aug 27, 1996
• Expiry date: Nov 21, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G21K2004/06
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A method, a storage phosphor prepared by the method, and a storage panel. In the method, a precursor mixture is fired, at a temperature between 700.degree. C. and the melting point of the phosphor, to produce an intermediate product. The precursor mixture comprises a combination of species characterized by the relationship: EQU MFX.sub.1-x I.sub.z.uM.sup.a X.sup.a :yA:eQ wherein M is selected from Mg, Ca, Sr and Ba; X is selected from Cl and Br; M.sup.a is selected from Na, K, Rb and Cs; X.sup.a is selected from F, Cl, Br and I; A is selected from Eu, Ce, Sm, and Tb; Q is metal oxide; and 0<z.ltoreq.1; 0<u<1; 0<y.ltoreq.0.1; and 0<e<0.1. The intermediate product is then annealed in a slightly oxidizing atmosphere, at a temperature, which is lower than said temperature of firing and between about 400.degree. C. and about 800.degree. C., for a time sufficient to reduce the erase fraction of the resulting phosphor relative to the same phosphor produced by firing in the same manner, but not annealing.