Magnetic field and pressure tuning of the heavy fermion antiferromagnet CePdIn

TL;DR

This study explores how magnetic fields and pressure influence the magnetic phases of the heavy fermion compound CePdIn, revealing two distinct antiferromagnetic phases and the role of Kondo hybridization in their evolution.

Contribution

It provides new insights into pressure- and field-induced phase transitions in CePdIn, highlighting the existence of two separate antiferromagnetic phases driven by electronic structure changes.

Findings

Two magnetic transitions suppressed by magnetic fields.

Non-monotonic evolution of $T_N$ with pressure, vanishing near 5 GPa.

Identification of two distinct antiferromagnetic phases separated near 2.6 GPa.

Abstract

Frustrated Kondo lattices are ideal platforms for studying how both the Kondo effect and quantum fluctuations compete with the magnetic exchange interactions that drive magnetic ordering. Here, we investigate the effect of tuning the heavy-fermion compound CePdIn, which crystallizes in the geometrically frustrated ZrNiAl-type structure, using applied magnetic fields and hydrostatic pressure. At ambient pressure, CePdIn exhibits two magnetic transitions, one at $T_{\rm{N}} \approx 1.65$ K and another at $T_{\rm{M}} \approx 1.15$ K, which are both suppressed by applied $c$-axis fields. Upon applying pressure in zero magnetic field, there is a non-monotonic evolution of $T_{\rm{N}}$, which decreases to 0.8 K at 2.3 GPa, before abruptly increasing to 1.5 K at 2.6 GPa. At higher pressures, $T_{\rm{N}}$ has a weak pressure dependence, and vanishes near 5 GPa. Together with the high-pressure phase being more robust to applied fields, these results suggest two distinct antiferromagnetic phases in CePdIn, which are separated near 2.6 GPa, and this change may be driven by the evolution of the underlying electronic structure due to enhanced Kondo hybridization under pressure.