Research on fluorescence spectra and structure of single-phase 4SrO centerdot 7Al(2)O(3): Eu2+ phosphor prepared by solid-state reaction method

In the view of material physical chemistry, the solid-state reaction proces s and phase-forming rule of 4SrO . 7Al(2)O(3) have been studied. It is veri fied that 3SrO . Al2O3 which is rich in strontium is formed firstly at appr oximate to 1000 degrees C, and with the calcining temperature going up to 1 300 degrees C gradually, aluminates rich in strontium change to the rich in aluminum in turn. In other words, strontium aluminates are found in the or der from 3SrO . Al2O3, SrO . Al2O3 to 4SrO . 7Al(2)O(3) and SrO . 6Al(2)O(3 ), and the aluminate is 4SrO . 7Al(2)O(3), which exists steadily at 1300 de grees C. The synthesis conditions of single-phase 4SrO . 7Al(2)O(3) are det ermined, and the data of X-ray powder diffraction and lattice structure of 4SrO . 7Al(2)O(3), which crystallizes in the orthorhombic Pmma space group with a = 24.765 Angstrom, b = 8.478 Angstrom and c = 4.882 Angstrom are pre sented. Also the differences of fluorescence spectrum between phosphor 4SrO . 7Al(2)O(3):Eu2+ and phosphor SrO . Al2O3:Eu2+ are discussed. And the rel iable basis is provided for the synthesis and determination of the new blue -green phosphor 4SrO . 7A(l)2O(3):Eu2+ with high efficiency. (C) 1998 Elsev ier Science S.A. All rights reserved.