掺Gd^(3+)钼酸盐AMoO_4(A=Ca,Sr,Ba,Pb)自旋哈密顿参量的理论计算

Theoretical investigation on the spin-Hamiltonian parameters for Gd^(3+)-doped molybdates AMoO_4(A = Ca,Sr,Ba,Pb)

采用基于单电子晶体场机制的对角化能量矩阵方法,计算了Gd3+在钼酸盐AMoO4(A=Ca,Sr,Ba,Pb)晶体中的自旋哈密顿参量(g因子g//,g⊥和零场分裂b20,b40,b44,b60,b64).矩阵中的晶体场参量采用重叠模型计算.计算结果显示,应用三个合理的可调参量[即重叠模型中的内禀参量2(R0),4(R0)和6(R0)],计算的七个自旋哈密顿参量与实验结果符合甚好,表明该方法可用于计算或解释Gd3+在晶体中的自旋哈密顿参量.

In this paper the spin-Hamiltonian parameters, g factors g//, g⊥ and zero-field splittings b20, b40, b44, b60, b64, for Gd3＋ ion in molybdates AMoO4 （A=Ca, Sr, Ba, Pb） are calculated by a diagonalization （of energy matrix） method based on one-electron crystal field mechanism. The crystal field parameters in the matrix are calculated from the superposition model. The results indicate that seven calculated spin-Hamiltonian parameters are in good agreement with the experimental values by using only three reasonable adjustable parameters （i.e., the intrinsic parameters Ak （R0）, where k=2, 4, 6, in the superposition model）. It is shown that the diagonalization method can be used to calculate and explain the spin-Hamiltonian parameters of Gd3＋ ion in crystals. The results are discussed.