Low-temperature transport properties of intermetallic compound HoAgGe with kagome spin ice state

TL;DR

This study investigates the low-temperature magnetic, electrical, and thermal transport properties of HoAgGe single crystals, revealing complex magnetic transitions and anisotropic responses linked to its kagome spin ice state.

Contribution

It provides detailed experimental insights into the magnetic and transport behaviors of HoAgGe, highlighting the effects of magnetic field orientation on its properties.

Findings

Metamagnetic transitions observed in magnetization curves.

Anomalies in susceptibility and resistivity at magnetic transition temperatures.

Distinct magnetoresistance and thermal conductivity responses depending on field direction.

Abstract

We study the magnetic susceptibility, magnetization, resistivity and thermal conductivity of intermetallic HoAgGe single crystals at low temperatures and in magnetic fields along the $a$ and $c$ axis, while the electric and heat currents are along the $c$ axis. The magnetization curves show a series of metamagnetic transitions and small hysteresis at low field for $B \parallel a$, and a weak metamagnetic transition for $B \parallel c$, respectively. Both the magnetic susceptibility and $\rho(T)$ curve show anomalies at the antiferromagnetic transition ($T\rm_N \sim$ 11.3 K) and spin reorientation transition ($\sim$ 7 K). In zero field and at very low temperatures, the electrons are found to be the main heat carriers. For $B \parallel a$, the $\rho(B)$ curves display large and positive transverse magnetoresistance (MR) with extraordinary field dependence between $B^2$ and $B$-linear, accompanied with anomalies at the metamagnetic transitions and low-field hysteresis; meanwhile, the $\kappa(B)$ mainly decrease with increasing field and display some anomalies at the metamagnetic transitions. For $B \parallel c$, there is weak and negative longitudinal MR while the $\kappa(B)$ show rather strong field dependence, indicating the role of phonon heat transport.