Mott versus Slater-type metal-insulator transition in Mn-substituted Sr3Ru2O7

TL;DR

This study investigates the nature of the metal-insulator transition in Mn-substituted Sr3Ru2O7, demonstrating it is driven by electronic correlations characteristic of a Mott transition rather than magnetic order, with implications for understanding its intrinsic instability.

Contribution

The paper provides experimental evidence distinguishing the Mott-type transition from Slater-type in Sr3(Ru1-xMnx)2O7, highlighting the role of local antiferromagnetic correlations and impurity effects.

Findings

MIT induces local antiferromagnetic correlations around Mn impurities

The transition is of Mott-type, driven by electronic correlations

The (1/4,1/4,0) order persists across various Mn concentrations

Abstract

We present a temperature-dependent x-ray absorption (XAS) and resonant elastic x-ray scattering (REXS) study of the metal-insulator transition (MIT) in Sr3(Ru1-xMnx)2O7. The XAS results reveal that the MIT drives the onset of local antiferromagnetic correlations around the Mn impurities, a precursor of the long-range antiferromagnetism detected by REXS at T_order<T_MIT. This establishes that the MIT is of the Mott-type (electronic correlations) as opposed to Slater-type (magnetic order). While this behavior is induced by Mn impurities, the (1/4,1/4,0) order exists for a wide range of Mn concentrations, and points to an inherent instability of the parent compound.