PHOSPHOR FOR X-RAY INTENSIFYING SCREEN, AND X-RAY INTENSIFYING SCREEN

摘要

PROBLEM TO BE SOLVED: To obtain a phosphor which has a high X-ray emission efficiency and a spectrum fitting to the spectral sensitivity of an X-ray film and of which the content of an afterglow component is low by forming a divalent-europium- activated alkaline earth metal fluoride halide phosphor represented by a specific formula. ;SOLUTION: This phosphor for an X-ray intensifying screen is a divalent- europium-activated alkaline earth metal fluoride halide phosphor represented by the formula: MFX.aM'X'.bEu, cLn and is prepared by mixing MF, MX, EuX", and LnX" in a specified molar ratio, baking the resultant mixture in a weakly reducing atmosphere (e.g. a carbon dioxide atmosphere containing carbon monoxide) at 600-1,000°C for 1-12 hr, breaking up the baking product in a solvent (e.g. methanol), and separating and drying the product. In the formula, 0a≤0.01; 0b≤0.2; 0c≤0.01; M is Ca, Sr, or Ba; M' is Li, Na, K, Rb, or Cs; Ln is Er, Tm, Ho, or Yb; X is Cl, Br, or I; and X' and X" are each F, Cl, Br, or I.;COPYRIGHT: (C)2000,JPO