Suppression of antiferromagnetic order and orthorhombic distortion in superconducting Ba(Fe0.961Rh0.039)2As2

TL;DR

This study uses neutron and x-ray diffraction to show that in Ba(Fe0.961Rh0.039)2As2, superconductivity suppresses antiferromagnetic order and orthorhombic distortion, highlighting the competition between these phases in electron-doped iron-based superconductors.

Contribution

It provides direct experimental evidence of the suppression of magnetic and structural order parameters below Tc in a specific Rh-doped iron pnictide superconductor.

Findings

Magnetic order decreases below Tc

Orthorhombic distortion diminishes below Tc

Superconductivity coexists and competes with magnetic order

Abstract

Neutron diffraction and high-resolution x-ray diffraction studies find that, similar to the closely related underdoped Ba(Fe[1-x]Cox)2As2 superconducting compounds, Ba(Fe0.961Rh0.039)2As2 shows strong evidence of competition and coexistence between superconductivity and antiferromagnetic order below the superconducting transition, Tc = 14 K. The transition temperatures for both the magnetic order and orthorhombic distortion are in excellent agreement with those inferred from resistivity measurements, and both order parameters manifest a distinct decrease in magnitude below Tc. These data suggest that the strong interaction between magnetism and superconductivity is a general feature of electron-doped Ba(Fe[1-x]TMx)2As2 superconductors (TM = Transition Metal).