OBSERVATION OF EU2-EU8+, TB8+( AND TB4+ IN SRMG4)

Europium(II) and terbium(LV) drive boon observed in SrMgF4: Eu3+, Tb5 phosphors which are synthesized in Ar stream. The valence state of eu ropium is influenced by terbium. It is notable that the intensities of electron paramagnetic resonance (EPR) peaks corresponding to Eu2+ are increased when Tb3+ ion is incorporated in SrMgF4:Eu3+ phosphors, whi le X-ray photoelectron spectra of Tb-8d5/2 in SrMgF4:Eu3+,Tb3+ shows a n additional peak at high energy to that of Tb-3d5/2 in SrMgF4: Tb3+, which is due to Tb4+. These phenomena can be explained by an electron transfer mechanism.