摘要
基于DSCPCF模型,本文给出LaOX:Eu^3(+)(X^-=Cl^-,Br^-,I^-)和Ln0Cl:Tb^(3+)(Ln^(3+)=La^(3+),Gd^(3+),Y^(3+))系列磷光体的配位场微扰能级,并对其液氮及液氦温度下的荧光光谱进行了理论归属.结果表明:(1)DSCPCF微扰能级与实测光谱较好吻合;(2)随着基质阴离子(Cl^-→Br^-→I^-)或阳离子(Y^(3+)→Gd^(3+)→La^(3+))离子半径增大,电负性降低,晶场参数B_m^k呈增大趋势;(3)配位场微扰导致的电子云膨胀效应与DSCPCF模型的特征参数——配体有效核电荷Z_j~*及键电荷qi的变化趋势相一致;(4)与PCF模型相比,DSCPCF模型使B_m^k的计算结果得到明显改善。
Based on Double Sphere Coordination Point Charge Field (DSCPCF) model. thecoordination field perturbation energy levels of Eu^(3+) and Tb^(3+) ions doped in LnOXmatrixes (Ln^(3+)= La^(3+), Gd^(3+), Y^(3+); X^- = Cl^-, Br^-, I^-) were calculated and thecorresponding spectra at liquid nitrogen and liquid helium temperature were assigned.The result shows that 1) the DSCPCF perturbation energy levels agree well with thespectra observed, 2) the coordination field parameters B_m^k show an increasing trendwith the increasing of the ionic radius al1d the clectronogativity of both Ln^(3+) and X-host ions, 3) the Nephelauxetic effect on RE ions and the orbital overlap betweenRE ion and its ligands are partly revealed by their characteristic parameters ----theeffective nuclear charge Z_j and the bond charge q_j in DSCPCF model, and 4) bycomparison with Point Charge Field (PCF) model, B_m^2 in DSCPCF model decreasesliggtly, while B_m^4 especially B_m^A increase greatly. This correction may overeome theshortcoming of PCF model in certain degree.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1990年第5期580-588,共9页
Acta Physico-Chimica Sinica
