| 摘要 |
1,212,638. Luminescent materials. WESTINGHOUSE ELECTRIC CORP. 9 April, 1969 [3 May, 1968], No. 18133/69. Heading C4S. A phosphor comprises a divalent Eu activated halophosphate of an alkaline earth metal, the halogen being at least one of F, Cl and Br. The phosphor is prepared by mixing the constituents with an excess of alkaline earth metal halide beyond. that required to provide the exact proportions such that halide provides at least 10 atom per cent of alkaline earth metal in the mix, firing the mixture in a reducing atmosphere and dissolving excess metal halide from the fired composition. Sr chlorophosphate is prepared from a mixture of SrHPO 4 , SrCO 2 , SrCl 2 . and EuCO 3 with additional SrCl 2 to act as a flux - during-firing in an alumina container at 1100‹ C. in N 2 -H 2 atmosphere. The fired material is broken up and excess SrCl 2 is washed away leaving particles which may be refined with NH 4 Cl. The resulting particles are shaped as hexagonal prisms. Ba and Ca may be substituted for Sr and F for Cl in percentages from 0 to 100. Eu 2 O 3 and EuCl 3 may replace EuCO 3 . Small amounts of Al added as Al(OH) 3 may replace Sr. |
