Ca_5(PO_4)_3Cl中铕和铽间的电子转移

ELECTRON TRANSFER BETWEEN Eu AND Tb IN Ca_5(PO_4)3Cl MATRIX

本文通过对铕和铽在Ｃａ５（ＰＯ４）３Ｃｌ基质中的发光特征的研究，发现铕和铽之间存在着电子转移现象，并对其反应机理进行了探讨。Ｅｕ３＋（４ｆ６）和Ｔｂ３＋（４ｆ８）通过电子转移使它们达到电子结构稳定的Ｅｕ２＋（４ｆ７）和Ｔｂ４＋（４ｆ７）。在同一基质中双掺铕和铽时，在２５４ｎｍ紫外光激发下，能同时观察到Ｅｕ２＋，Ｅｕ３＋和Ｔｂ３＋的发射，这一现象的发现为单基双掺希土三基色荧光粉的研制提供了理论依据。

The luminescent properties of europium and terbium in Ca_5(PO_4)3Cl matrix have been studied, and we find that an electron transfer takes place between Eu^3+ and Tb^3+ ions: Eu^3+(4f6)+Tb^3+(4f8)→Eu~2+(4f7)+Tb^4+(4f7). We have investigated the reaction mechanism. Eu^3+ and Tb^3+ ions tend to transfer an electron to get their more stable configurationEu^2+(4f7) and Tb^4+(4f7) ions. When Eu^3+ and Tb^3+ ions are codoped in Ca_5(PO_4)3Cl matrix, the emission spectra of Eu^2+, Eu^3+ and Tb^3+ ions are all observed under 254 nm excitation. We proposed a new method to synthesize a new trichromatic lamp phosphor that europium and terbium are codoped in only one matrix.