The identification of electronic states and the analysis of their evolution with n is key to understanding n-layered ruthenates. To this end, we combine polarization-dependent O 1s x-ray absorption spectroscopy, high-purity Srn+1RunO3n+1 (n = 1,2,3) single crystals, and ab initio and many-body calculations. We find that the energy splitting between the empty x(2) - y(2) and 3z(2) - 1 state is considerably smaller than previously suggested and that, remarkably, Sr bands are essential to understanding the spectra. At low energy, we identify the main difference among the materials with a substantial rearrangement of t(2g) orbital occupations with increasing n. This rearrangement is controlled by the interplay of Coulomb repulsion, dimensionality, and changes in the t(2g) crystal field.
Electronic structure trends in the Sr(n+1)Ru(n)O(3n+1) family (n=1,2,3)
Fittipaldi R;Cuoco M;Parmigiani F;Vecchione A
2011
Abstract
The identification of electronic states and the analysis of their evolution with n is key to understanding n-layered ruthenates. To this end, we combine polarization-dependent O 1s x-ray absorption spectroscopy, high-purity Srn+1RunO3n+1 (n = 1,2,3) single crystals, and ab initio and many-body calculations. We find that the energy splitting between the empty x(2) - y(2) and 3z(2) - 1 state is considerably smaller than previously suggested and that, remarkably, Sr bands are essential to understanding the spectra. At low energy, we identify the main difference among the materials with a substantial rearrangement of t(2g) orbital occupations with increasing n. This rearrangement is controlled by the interplay of Coulomb repulsion, dimensionality, and changes in the t(2g) crystal field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
