FeAs-based superconductivity: a case study of the effects of transition metal doping on BaFe2As2

TL;DR

This paper reviews the impact of transition metal doping on BaFe2As2, highlighting how doping influences phase transitions and enables superconductivity in FeAs-based materials with high transition temperatures.

Contribution

It provides a comprehensive overview of how TM doping affects the phase diagram and superconductivity in BaFe2As2, offering insights into the interplay of structural, magnetic, and superconducting phases.

Findings

Doping with Co, Ni, Cu, Pd, Rh induces superconductivity in BaFe2As2.

Phase diagrams show the relationship between doping levels and phase transitions.

Superconductivity is stabilized within specific doping regions.

Abstract

The recently discovered FeAs-based superconductors are a new, promising set of materials for both technological as well as basic research. They offer transition temperatures as high as 55 K as well as essentially isotropic and extremely large upper, superconducting critical fields in excess of 40 T at 20 K. In addition they may well provide insight into exotic superconductivity that extends beyond just FeAs-based superconductivity, perhaps even shedding light on the still perplexing CuO-based high-Tc materials. Whereas superconductivity can be induced in the RFeAsO (R = rare earth) and AEFe2As2 (AE = Ba, Sr, Ca)) families by a number of means, transition metal doping of BaFe2As2, e.g. Ba(Fe1-xTMx)2As2, offers the easiest experimental access to a wide set of materials. In this review we present an overview and summary of the effect of TM doping (TM = Co, Ni, Cu, Pd, and Rh) on BaFe2As2. The resulting phase diagrams reveal the nature of the interaction between the structural, magnetic and superconducting phase transitions in these compounds and delineate a region of phase space that allows for the stabilization of superconductivity.