Magnetic and electrical transport properties of the single-crystalline half-Heusler antiferromagnet DyNiSb

TL;DR

This study reveals complex magnetic and electrical transport behaviors in high-quality DyNiSb single crystals, including multiple magnetic transitions, metallic conductivity, and field-induced Fermi surface changes, contrasting with previous polycrystalline results.

Contribution

The paper provides detailed low-temperature magnetic and transport measurements on single-crystalline DyNiSb, uncovering multiple magnetic phases and metallic behavior not observed in polycrystals, and demonstrates field-tunable electronic properties.

Findings

Two magnetic phase transitions at 7.3 K and 3.4 K

Metallic conductivity in single crystals

Field-induced Fermi surface reconstruction

Abstract

High-quality single crystals of the half-Heusler compound DyNiSb were investigated for their low temperature thermodynamic and magnetotransport properties. Magnetic susceptibility, heat capacity, and electrical resistivity measurements revealed two distinct magnetic phase transitions at TN1 = 7.3 K and TN2 = 3.4 K, contrasting with previous reports on polycrystalline samples, which identified only a single transition near TN2 . Moreover, the studied samples were found to exhibit Metal like conductivity, at odds with a semiconducting behavior reported for the polycrystals. Magnetoresistance measurements performed in both transverse and longitudinal configurations revealed in small magnetic fields a weak antilocalization effect that diminishes with increasing temperature, giving way to a positive, monotonic magnetoresistance at high temperatures. Angular-dependent resistivity studies showed a crossover from fourfold to twofold symmetry with increasing magnetic-field strength, suggesting a field-induced reconstruction of the Fermi surface. Our findings highlight a complex magnetic and electrical transport behavior in DyNiSb, highly sensitive to structural disorder and easily tunable by external magnetic field.