Yb3+掺杂稀土钽铌酸盐的晶体场从头计算研究

Yb³⁺掺杂晶体材料是重要的激光材料,在超短脉冲激光、大功率激光等领域有重要应用前景,但长期以来很难通过实验拟合确定Yb3+晶体场参数,尤其是低对称体系,从头计算是解决此问题的重要途经.本文介绍了适合计算稀土离子掺杂晶体的从头计算DV-Xα方法和有效哈密顿量模型,用该方法计算了Yb³⁺掺杂M型和M'型钽铌酸盐的晶场参数和旋轨耦合参数,得到的能级结构和实验能很好地符合,并发现了Yb³⁺掺杂钽铌酸盐的晶场强度参数随稀土原子序数呈现规律变化.表明结合DV-Xα计算和有效哈密顿量方法是计算Yb³⁺掺杂低对称钽铌酸盐晶体场的有效途径,结果显示Yb3+掺杂钽铌酸盐晶体有望成为新型全固态激光工作物质.

Ab-Initio Calculations of the Crystal Field of Yb^3+ Doped inTantalate and Niobate

Yb^3+doped crystal material,an important laser material,has promising applications in the fields of ultra short pulse laser and high power laser.However,it was very difficult to determine the crystal field parameters of Yb^3+,especially of the hosts with low-symmetry.Ab-initio calculation was an important way to solve this problem.In this paper,the ab-initio DV-Xαmethod and the effective Hamiltonian model were introduced,which was suitable for calculating rare earth ion doped in hosts.With the ab-initio DV-Xαmethod and effective Hamiltonian model,the crystal field parameters of Yb^3+doped in the tantalite and niobate with M-type and M'-type were calculated.It is concluded that the part energy level structure fits well with the experimental spectra.And the crystal field parameters of Yb^3+doped in the tantalite and niobate show regular changes with the atomic numbers of rare earth.It is shown that DV-Xαmethod and effective Hamiltonian model are effective methods to calculate the crystal field of Yb^3+doped in the tantalite and niobate with low-symmetry,Yb^3+doped in the tantalite and niobate is the potential laser medium for high eifficiency laser operation.