Local Magnetic States of the Weakly Ferromagnetic Iron-Based Superconductor Sr$_2$VFeAsO$_{3-\delta}$ Studied by X-ray Magnetic Circular Dichroism

TL;DR

This study uses X-ray magnetic circular dichroism to investigate the origin of weak ferromagnetism in Sr$_2$VFeAsO$_{3-eta}$, revealing V 3d electrons' role in the phenomenon.

Contribution

It provides the first direct evidence linking V 3d electrons to weak ferromagnetism in this iron-based superconductor.

Findings

V 3d electrons contribute to weak ferromagnetism

Fe 3d electrons behave like in other iron pnictides

Finite magnetic signals from V 3d electrons at zero field

Abstract

We have performed x-ray magnetic circular dichroism (XMCD) measurements on the iron-based superconductor Sr$_2$VFeAsO$_{3-\delta}$ to study the origin of weak ferromagnetism (WFM) reported for this compound. While Fe 3$d$ electrons show a magnetic response similar to the other iron pnictides, signals from V 3$d$ electrons remain finite at zero magnetic field and may be responsible for the WFM.