Influence of hydrostatic pressure on the bulk magnetic properties of Eu$_{2}$Ir$_{2}$O$_{7}$

TL;DR

This study investigates how hydrostatic pressure affects the magnetic transition temperature and local magnetic structure of Eu₂Ir₂O₇, revealing non-monotonic pressure dependence and supporting the preservation of a specific magnetic ground state.

Contribution

It provides experimental evidence for pressure-induced changes in magnetic properties and supports theoretical models of the magnetic phase diagram in Eu₂Ir₂O₇.

Findings

Non-monotonic pressure dependence of T_N observed

Magnetic configuration remains weakly perturbed at low pressures

Results support preservation of 4-in/4-out magnetic ground state

Abstract

We report on the magnetic properties of Eu$_{2}$Ir$_{2}$O$_{7}$ upon the application of hydrostatic pressure $P$ by means of macroscopic and local-probe techniques. In contrast to previously reported resistivity measurements, our dc magnetization data unambiguously demonstrate a non-monotonic $P$-dependence for $T_{N}$, i.~e., the critical transition temperature to the magnetic phase. More strikingly, we closely reproduce the recently calculated behaviour for $T_{N}$ under the assumption that $P$ lowers the $U/W$ ratio (i.~e., Coulomb repulsion energy over electronic bandwidth). Zero-field muon-spin spectroscopy measurements confirm that the local magnetic configuration is only weakly perturbed by low $P$ values, in agreement with theoretical predictions. The current results experimentally support the preservation of a $4$-in/$4$-out ground state and, simultaneously, a departure from the single-band $j_{\text{eff}} = 1/2$ model across the accessed region of the phase diagram.