Depth dependence of itinerant character in Mn-substituted Sr3Ru2O7

TL;DR

This study investigates how Mn substitution affects the electronic character of Sr3Ru2O7, revealing a transition from itinerant to localized electrons and depth-dependent differences between surface and bulk properties.

Contribution

It provides the first detailed core-level photoemission analysis showing depth-dependent electronic character changes due to Mn doping in Sr3Ru2O7.

Findings

Suppression of metallic features with Mn substitution

Transition from itinerant to localized electronic character

Differences in surface and bulk electronic states

Abstract

We present a core-level photoemission study of Sr3(Ru 1-xMnx)2O7, in which we monitor the evolution of the Ru-3d fine structure versus Mn substitution and probing depth. In both Ru 3d3/2 and 3d5/2 core levels we observe a clear suppression of the metallic features, i.e. the screened peaks, implying a sharp transition from itinerant to localized character already at low Mn concentrations. The comparison between soft and hard x-ray photoemission, which provides tunable depth sensitivity, reveals that the degree of localized/metallic character for Ru is different at the surface than in the bulk.