Tuning magnetic phase transitions and anomalous Hall effect in Weyl semimetal Nd1-xPrxAlSi single crystals

Abstract

Rare-earth-based magnetic Weyl semimetals RAlX offer a fertile platform to explore the interplay between nontrivial topology and magnetic order. Here, we report the successful synthesis of Nd 1− x Pr x AlSi ( x = 0–0.7) single crystals and demonstrate that Pr doping effectively tailors the magnetic ground state and unlocks large AHE signals. Systematic characterization reveals that Pr substitution suppresses the intrinsic incommensurate helical antiferromagnetic and ferrimagnetic phases of NdAlSi, driving a magnetic phase transition from a multi-step process to a single ferromagnetic ordering above x = 0.5. Concomitantly, the anomalous Hall conductivity σ xy A reaches a maximum of 2790 Ω −1 cm −1 for x = 0.7. Crucially, scaling analysis of σ xy A versus longitudinal conductivity σ xx reveals a linear dependence ( σ xy A ∝ σ xx ), unequivocally identifying the extrinsic skew-scattering mechanism as the dominant origin of the large AHE. Our work provides a chemical strategy to tune the magnetic ground state and activate extrinsic topological transport in RAlX families.