Electron transfer between Eu3+ and Tb3+ in BaB4O7 matrix

The BaB4O7:Eu, Tb phosphors are first synthesized in air atmosphere. We investigate their luminescent properties, and find that europium(II) and europium(III) can coexist in the BaB4O7:Eu phosphor. We observed that the relative intensity of europium(II) is increased when terbium(III) is incorporated. The electron spin resonance (ESR) spectra are carried out. The intensity of ESR peaks corresponding to europium(II) is also increased when terbium(III) is increased, so the valency state of europium is influenced by terbium(III). We explain these phenomena by an electron transfer mechanism. (C) 1996 Academic Press, Inc.

Electron transfer between Eu3+ and Ce3+ in SrM-F-4 matrix

Emissions of europium (II) and europium (III) have been observed in SrMgF4:Eu and SrMgF4:Eu,Ce phosphors which are synthesized in Ar flow, It is notable that the intensity of the ESR peaks corresponding to Eu2+ is increased when cerium ion is incorporated which can be explained by electron transfer mechanism.

EXTENDED ADJACENCY MATRIX INDEXES AND THEIR APPLICATIONS

In this paper, new topological indices, EA Sigma and EAmax, are introduced. They are based on the extended adjacency matrices of molecules, in which the influences of factors of heteroatoms and multiple bonds were considered. The results show that EA Sigm