Doping and dimensionality effects on the core-level spectra of layered ruthenates

TL;DR

This study investigates how doping and structural dimensionality influence the core-level spectra of layered ruthenates, revealing effects on electron localization and chemical environment through X-ray photoelectron spectroscopy.

Contribution

It provides new insights into doping effects and structural influences on core-level spectra in layered ruthenates, highlighting changes in electron localization and chemical bonding.

Findings

Mn doping affects Ru 3d spectral weight distribution

Ru 3p levels remain unchanged with doping

Sr 3d levels shift with increasing layer number

Abstract

Core-level spectra of the Mn-doped Sr3Ru2O7 and Srn+1RunO3n+1 (n = 1, 2 and 3) crystals are investigated with X-ray photoelectron spectroscopy. Doping of Mn to Sr3Ru2O7 considerably affects the distribution of core-level spectral weight. The satellite of Ru 3d core levels exhibits a substantial change with doping, indicating an enhanced electron localization across the doping- induced metal-insulator transition. However, the Ru 3p core levels remain identical with Mn-doping, thus showing no sign of doping-induced multiple Ru valences. In the Srn+1RunO3n+1 (n = 1, 2 and 3), the Ru 3d core-level spectra are similar, indicating that the chemical bonding environment around Ru ions remains the same for different layered compounds. Meanwhile the Sr 3d shallow core levels shift to higher binding energy with increasing n, suggesting their participation in Sr-O bonding with structural evolution.