Chemical Pressure and Physical Pressure in BaFe_2(As_{1-x}P_{x})_2

TL;DR

This study compares the effects of chemical pressure via phosphorous substitution and physical pressure on the superconducting transition temperature in BaFe_2(As_{1-x}P_x)_2, finding both methods produce similar phase diagrams and do not cause significant impurity scattering.

Contribution

It demonstrates that chemical and physical pressures have equivalent effects on T_c and phase diagrams in BaFe_2(As_{1-x}P_x)_2, clarifying their relationship in tuning superconductivity.

Findings

Maximum T_c of 31 K under both pressures

Chemical substitution does not cause significant impurity scattering

Phase diagrams are similar for chemical and physical pressure

Abstract

Measurements of the superconducting transition temperature, T_c, under hydrostatic pressure via bulk AC susceptibility were carried out on several concentrations of phosphorous substitution in BaFe_2(As_{1-x}P_x)_2. The pressure dependence of unsubstituted BaFe_2As_2, phosphorous concentration dependence of BaFe_2(As_{1-x}P_x)_2, as well as the pressure dependence of BaFe_2(As_{1-x}P_x)_2 all point towards an identical maximum T_c of 31 K. This demonstrates that phosphorous substitution and physical pressure result in similar superconducting phase diagrams, and that phosphorous substitution does not induce substantial impurity scattering.