PRECURSOR COMPOUND AND CRYSTALLISED COMPOUND OF THE ALKALINE-EARTH ALUMINATE TYPE, AND METHODS OF PREPARING AND USING THE CRYSTALLISED COMPOUND AS PHOSPHOR.

摘要

The invention relates to an alkaline-earth-aluminate-type compound whichis at least partially crystallised such as in the form of a beta- or tridymite-typealumina and which comprises a composition having formula a(M1O).b(MgO).c(Al2O3),in which M1 denotes at least one alkaline-earth and a, b and c are integeror non-integer numbers whereby 0.25 = a = 4, O = b = 2 and 0.5 = c = 9, M1 beingpartially substituted by europium and at least one other element belonging tothe group of rare earths having an ionic radius of less than that of Eu3+. In addition, the compound takes the form of substantially-whole particleswith a maximum average size of 6 ?m. Said compound can be used as phosphor in plasma-typescreens or in trichromatic lamps, backlights for liquid crystal displays orplasma excitation lighting or in light-emitting diodes. The invention alsorelates to a precursor compound of the aforementioned compound.