Investigation of magnetic and magneto-transport properties in non-centrosymmetric antiferromagnetic semimetal GdGaSi

TL;DR

This study combines theoretical and experimental approaches to explore the magnetic and magneto-transport properties of GdGaSi, revealing its antiferromagnetic semimetallic nature with notable electron transport characteristics.

Contribution

It provides the first comprehensive investigation of GdGaSi's magnetic and transport properties, highlighting its non-centrosymmetric structure and correlated magnetic and electronic behaviors.

Findings

GdGaSi is an antiferromagnetic semimetal with a Neel temperature of 19 K.

Positive magnetoresistance of approximately 2% at 2 K and 8 T observed.

Electron-type charge carriers dominate the transport properties.

Abstract

In this work, we investigated the magneto-transport and magnetic properties of GdGaSi, having non-centrosymmetric tetragonal structure, with space group $I4_1md$. Our theoretical results are supported by experimental studies. First-principles calculations reveal that GdGaSi is an antiferromagnetic semimetallic system, characterized by dominant electron-type charge carriers. In addition, the possible nontriviality of the crossing at the Fermi energy is consistent with isostructural LaPtSi-structured materials. The compound shows robust antiferromagnetic (AFM) ordering with a N\'eel temperature of 19 K, and spin-reorientation signature below $T_N$. The semimetallic nature with positive magnetoresistance ($\simeq$ 2\% at 2 K and 8 T) is observed from the magnetotransport data, having electrons as majority charge carrier, established from the Hall measurements. The strong correlation in magnetism and transport is supported by various observations, like (1) concordant transitions in $M(T)$ and $\rho (T)$ data, (2) change in the concentration and mobility of electron below $T_N$, and (3) splitting of Kohler's plots in the two branches across the transition. Thus, our findings establish GdGaSi as a material with intertwined magnetic and transport degrees of freedom, within noncentrosymmetric lattice.