Ab initio and crystal field studies of the Mn4+-doped Ba2LaNbO6 double-perovskite

作者：Srivastava, A. M.^*; Brik, M. G.

来源：Journal of Luminescence, 2012, 132(3): 579-584.

DOI：10.1016/j.jlumin.2011.09.017

• Perovskite
• Ba2LaNbO6
• Mn4+
• Ab initio DFT based calculations
• Energy level scheme

A detailed study using the ab initio DFT-based calculations of the electronic and optical properties of pure and Mn4+ doped Ba2LaNbO6 is presented in this paper. Comparison of the calculated electronic bands structure, density of states diagrams, and dielectric functions for the pure and doped crystal reveals the changes induced by the Mn4+ impurity ions. In addition, the energy levels of the Mn4+ ion in the ordered perovskite Ba2LaNbO6 are calculated by the exchange charge model (ECM) of crystal field theory and compared with the experimental data that has been presented in the literature. The calculated Mn4+ energy levels are in good agreement with the experimental spectra. Additionally, the excitation band shapes of the (4)A(2g)(F-4)-T-4(2g)(F-4) and (4)A(2g)(F-4)-T-4(1g)(F-4) transitions are modeled to estimate the zero-phonon lines (ZPL) positions and the effective number of phonons, which are involved in the corresponding excitation transition. The results of our calculations yield the crystal field parameter of D-q=1780 cm(-1) and Racah parameters B=670 and C=3290 cm(-1) with C/B=4.9 for the Mn4+ ion in the double-perovskite Ba2LaNbO6.

• 出版日期2012-3