Numerical quantification of the vibronic broadening of the SrTiO3 Ti L-edge spectrum
Keith Gilmore, Eric L. Shirley
The 2p5-3d1 excited state of the Ti4+ ion in SrTiO3 couples to e_g distortions of the oxygen cage leading to a Jahn-Teller splitting of the degenerate excited states, which are additionally broadened by a Franck-Condon emission of phonons. We quantify these contributions to the broadening of the spectral features of the Ti L-edge of SrTiO3 by solving a model Hamiltonian, taking parameters for the Hamiltonian from previous first-principles calculations. Evaluation of the model Hamiltonian indicates that this vibronic coupling accounts for the majority of the broadening observed for the L_3-edge, but only a minority of the L_2-edge spectral width. The calculations reveal that, with increasing temperature, the spectral features become increasingly asymmetric and the amount of vibronic broadening grows approximately linearly.
and Shirley, E.
Numerical quantification of the vibronic broadening of the SrTiO3 Ti L-edge spectrum, Journal of Physics: Condensed Matter, [online], https://doi.org/10.1088/0953-8984/22/31/315901
(Accessed December 2, 2023)