Ambient and high-pressure electrical transport and structural investigations of magnetic Weyl semimetal PrAlGe

TL;DR

This study investigates the effects of ambient and high pressure on the electrical transport and structural properties of the magnetic Weyl semimetal PrAlGe, revealing pressure-induced electronic transitions and structural stability up to high pressures.

Contribution

It provides the first detailed high-pressure analysis of PrAlGe's magnetic and electronic properties, identifying an isostructural transition linked to electronic changes.

Findings

$T_C$ increases with pressure up to 47 K at 23 GPa

An anomaly at 12.5 GPa indicates a pressure-induced electronic transition

Lattice structure remains stable up to 19.6 GPa with an isostructural transition near 11 GPa

Abstract

We present ambient and high-pressure electrical transport and structural properties of recently discovered magnetic Weyl semimetal PrAlGe. Electrical resistivity at ambient pressure shows an anomaly at $T_C$ = 15.1 K related to the ferromagnetic transition. Anomalous Hall effect (AHE) is observed below $T_C$. We observe a 1.4 K/GPa increase of $T_C$ with pressure, resulting in $T_C$ $\approx$ 47 K at 23.0 GPa. Strong competition between Lorentz force and spin-scattering mechanisms suppressed by magnetic field is deduced from the magnetoresistance measurements under pressure. As in the ambient pressure case, the AHE is found to be present below $T_C$ up to the highest applied pressure. We observe a clear anomaly in the pressure dependence of $T_C$, magnetoresistance and Hall effect at 12.5 GPa suggesting the occurrence of a pressure-induced electronic transition at this pressure. X-ray diffraction (XRD) experiment under pressure revealed the lattice structure to be stable up to $\sim$19.6 GPa with the absence of any symmetry changing structural phase transition from the initial $I4_1md$ structure. Careful analysis of the pressure dependent XRD data reveal an isostructural transition near 11 GPa. Observed isostructural transition may be related to the pressure-induced electronic transition deduced from the magnetoresistance and Hall effect data.