Competing magnetic ground states in non-superconducting Ba(Fe1-xCrx)2As2

TL;DR

This study investigates how chromium doping affects magnetic ground states in Ba(Fe1-xCrx)2As2, revealing a transition from SDW to G-type antiferromagnetic order and explaining the lack of superconductivity.

Contribution

It provides detailed neutron diffraction analysis of magnetic phase evolution in Cr-doped BaFe2As2, identifying a new G-type antiferromagnetic phase at high Cr concentrations.

Findings

SDW moment remains constant for x<=0.2

Rapid decrease of SDW moment for x>=0.3

Emergence of G-type antiferromagnetic phase at x>0.3

Abstract

We present neutron diffraction measurements on single crystal samples of non-superconducting Ba(Fe1-xCrx)2As2 as a function of Cr-doping for 0<=x<=0.47. The average SDW moment is independent of concentration for x<=0.2 and decreases rapidly for x>=0.3. For concentrations in excess of 30% chromium, we find a new G-type antiferromagnetic phase which rapidly becomes the dominant magnetic ground state. Strong magnetism is observed for all concentrations measured and competition between these ordered states and superconductivity naturally explains the absence of superconductivity in the Cr-doped materials.