Fig. 4: ab initio and multiplet calculations compared to experimental EELS.
From: Atomic scale crystal field mapping of polar vortices in oxide superlattices
a Theoretical local polarization profile of polydomain structures in PTO/STO superlattices. Background gray scale represents the local tetragonality. b Experimental polar displacement of A sites with c/a ratio maps overlaid in the background. c Change in crystal field parameters (\(\triangle {e}_{g}\) in orange, \(\triangle {t}_{2g}\) in green, and CFS in magenta) at five different positions of the Ti4+ ions within the superlattice, as indicated in a. The inset shows the overlapping of the Ti \({3d}_{{z}^{2}}\) orbital and the O \(2p\) orbital as the \(c/a\) ratio (points 1 and 2), the direction (points 1 and 3), and magnitude (points 4 and 5) of the Ti4+ displacement. d Comparison of multiplet calculated EEL spectra using parameters in b as inputs and experimental EEL spectra for the five Ti4+ positions.
