PRECURSOR COMPOUND AND CRYSTALLIZED ALKALINO-TERROUS ALUMINATE COMPOUND, PROCESSES FOR THE PREPARATION AND USE OF THE CRYSTALLIZED COMPOUND AS LUMINOPHORE

摘要

The compound of the invention is of the alkaline earth aluminate type, crystallized at least partly in the form of a beta or tridimite type alumina in particular, and it has a composition of formula a (M10) .b (MgO). c (Al2O3) wherein M1 is at least one alkaline earth and a, b and c are integer or non-integers satisfying the relationship of 0.25 ≤ a ≤ 4; 0 ≤ b ≤ 2 and 0.5 ≤ c ≤ 9; M1 being partially substituted by europium and at least one other element belonging to the group of rare earths whose ionic radius is lower than that of Eu3 +. It is also in the form of substantially whole particles and average size of at most 6 m. It can be used as a phosphor in plasma type screens or in trichromatic lamps, backlighting LCD screens or plasma excitation lighting or in light emitting diodes. The invention also relates to a precursor compound of the above compound.