Doping evolution of antiferromagnetism and transport properties in the non-superconducting BaFe2-2xNixCrxAs2

TL;DR

This study investigates how doping with Ni and Cr affects antiferromagnetism and transport properties in BaFe2-2xNixCrxAs2, revealing suppression of magnetic order without superconductivity and highlighting impurity scattering effects.

Contribution

It provides new insights into the doping evolution of magnetic and transport behaviors in BaFe2-2xNixCrxAs2, emphasizing the role of Cr impurities and the absence of superconductivity.

Findings

Antiferromagnetic order is suppressed near x=0.20 without superconductivity.

Cr impurity scattering influences transport properties and can cause metal-insulator crossover.

Non-Fermi-liquid behavior may not directly relate to static AF order disappearance.

Abstract

We report elastic neutron scattering and transport measurements on the Ni and Cr equivalently doped iron pnictide BaFe$_{2-2x}$Ni$_{x}$Cr$_{x}$As$_{2}$. Compared with the electron-doped BaFe$_{2-x}$Ni$_{x}$As$_{2}$, the long-range antiferromagnetic (AF) order in BaFe$_{2-2x}$Ni$_{x}$Cr$_{x}$As$_{2}$ is gradually suppressed with vanishing ordered moment and N\'{e}el temperature near $x= 0.20$ without the appearance of superconductivity. A detailed analysis on the transport properties of BaFe$_{2-x}$Ni$_{x}$As and BaFe$_{2-2x}$Ni$_{x}$Cr$_{x}$As$_{2}$ suggests that the non-Fermi-liquid behavior associated with the linear resistivity as a function of temperature may not correspond to the disappearance of the static AF order. From the temperature dependence of the resistivity in overdoped compounds without static AF order, we find that the transport properties are actually affected by Cr impurity scattering, which may induce a metal-to-insulator crossover in highly doped BaFe$_{1.7-y}$Ni$_{0.3}$Cr$_{y}$As$_{2}$.