摘要
本文利用光谱方法测定了SmP_5O_(14)晶体中Sm^(3+)离子的能级,通过拟合定出晶场参数,利用这些参数所计算的能级和实验能级符合得很好。
Crystal field parameters for SmP5O14 crystals in the approximation of C2v point group symmetry and the reduced matrix elements(f5a SLJ//Uk//f5 a'S'L'J') were calculated.The crystal field parameters were fitted and the values of energy levels of Sm3+ ions were calculated. Beside these, calculated values of energy levels were compared with the experimental values which were measured from spectra.The paper is composed of three parts. Energy level were measured and are reported in part one. We measured fluorescence spectra of 4G6/2 -6H6/2 ,6H7/2, 6H9/1 , 6H11/2 and absorption spectra in infrared region for SmP5O14 crystals at liquied nitrogen temperature. According to these spectra, the stark energy levels which are lower than 4G5/2 level are appointed for Sm3+ ions in SmP6O14 crystals. Experimental energy levels are shown in Table 2. Part two involves the calculation techniques of crystal field. A concrete technique was given for C2v point group after analyzing the general expression of crystal field potential energy, those arc: (1) calculaion of reduced matrix elements (f5aSLJ//Uk// F5a' S'L/J').(f5aSLJ//Uk//f5a'S'L'J')=In calculation, the intermediate coupled wave functions given by B.G.Wybourne was used. The calculated results of this reduced matrix element are shown in Table 1. (2.) by means of the theorem of Wigner - Ecart, the matrix element between the states was obtained:According to these expressions and the reduced matrix elements in Table 1, parametric potential energy matrix of crystal field was obtained. In part three, the fitting process is explained in detail. In the fitting process, initial values of crystal field parameters were given. By means of JACOB, the potential energy matrix of crystal field was changed into diagonalization. The calculated values of energy levels Were compared with experimental values. By means of mean square deviation between the values of calculation and experiment. the calculated results were appraised. Computer changed the crystal field parameters continually for the leas
出处
《发光学报》
EI
CAS
CSCD
北大核心
1989年第3期206-206,212,共2页
Chinese Journal of Luminescence
