Effect of pressure and Ir substitution in YbRh2Si2

TL;DR

This study investigates how pressure and Ir substitution influence the electrical resistivity and magnetic phase transitions in YbRh2Si2, revealing proximity to a quantum critical point with minimal disorder effects.

Contribution

It demonstrates that Ir substitution acts as chemical pressure and that the system remains near a quantum critical point under applied pressure, with minimal disorder influence.

Findings

Ir substitution suppresses antiferromagnetic transition temperature.

Yb(Rh0.94Ir0.06)2Si2 is near a volume-controlled QCP.

Disorder effects from substitution are minor.

Abstract

In this article we present a study of the electrical resistivity of Yb(Rh-xIrx)2Si2, x=0.06, under high pressure and in magnetic field. Ir substitution is expanding the unit cell and leads to a suppression of the antiferromagnetic transition temperature to zero, where eventually a quantum critical point (QCP) exists. We applied hydrostatic pressure to reverse the effect of substitution. Our results indicate that Yb(Rh0.94Ir0.06)2Si2 is situated in the immediate proximity to a volume controlled QCP, but still on the magnetically ordered side of the phase diagram. The temperature - pressure phase diagram of Yb(Rh0.94Ir0.06)2Si2 resembles that of the pure compound. Substitution acts mainly as chemical pressure. Disorder introduced by substitution has only minor effects.