Complex single-site magnetism and magnetotransport in single-crystalline Gd$_{2}$AlSi$_{3}$

TL;DR

This study investigates the magnetic and transport properties of single-crystal Gd$_{2}$AlSi$_{3}$, revealing complex magnetic phases, anisotropic behavior, and potential skyrmionic phenomena in a tetragonal structure with two antiferromagnetic transitions.

Contribution

It provides the first detailed analysis of magnetic phases and anisotropy in Gd$_{2}$AlSi$_{3}$, highlighting multiple antiferromagnetic transitions and their effects on magnetotransport.

Findings

Two antiferromagnetic transitions at 32K and 23K.

Complex magnetic anisotropy affecting transport.

Identification of field-induced skyrmionic behavior.

Abstract

We present a detailed investigation of single-crystal samples of the magnetic compound Gd$_{2}$AlSi$_{3}$, which crystallizes in the $\alpha$-ThSi$_2$ type tetragonal structure. We report the temperature and magnetic field dependence of the magnetic susceptibility, magnetization, heat capacity, electrical resistivity, and magnetoresistance for magnetic fields applied along both the tetragonal $c$-axis and in the basal $ab$-plane. X-ray diffraction measurements confirm a centrosymmetric, $I4_{1}/amd$ space group of the crystal structure. Despite single-site occupancy of the Gd position in this tetragonal structure, we identify two successive antiferromagnetic phase transitions at Ne\'el temperatures 32~K and 23~K via magnetic susceptibility, heat capacity and transport measurements, as well as a complex magnetic interaction with a magnetic anisotropy that plays an important role in the direction-dependent transport response. Our identification of multiple magnetic phases in Gd$_{2}$AlSi$_{3}$, where Gd is the only magnetic species, helps to elucidate the field-induced skyrmionic behavior in the Gd-based intermetallic compounds.