Double-phase transition and giant positive magnetoresistance in the quasi-skutterudite Gd$_3$Ir$_4$Sn$_{13}$

TL;DR

This study uncovers a double magnetic phase transition and a giant positive magnetoresistance in Gd$_3$Ir$_4$Sn$_{13}$, revealing complex magnetic and electronic interactions in this quasi-skutterudite compound.

Contribution

It reports the first observation of a double-phase magnetic transition and giant magnetoresistance in Gd$_3$Ir$_4$Sn$_{13}$, highlighting novel magnetic and transport phenomena.

Findings

Double magnetic phase transition at 10 K and 8.8 K.

Giant positive magnetoresistance of approximately 80% at 2 K under 9 T.

Close connection between magnetic transitions and electronic/thermal transport.

Abstract

The magnetic, thermodynamic and electrical/thermal transport properties of the caged-structure quasi-skutterudite Gd$_3$Ir$_4$Sn$_{13}$ are re-investigated. The magnetization $M(T)$, specific heat $C_p(T)$ and the resistivity $\rho(T)$ reveal a double-phase transition -- at $T_{N1}\sim$ 10~K and at $T_{N2}\sim$ 8.8~K -- which was not observed in the previous report on this compound. The antiferromagnetic transition is also visible in the thermal transport data, thereby suggesting a close connection between the electronic and lattice degrees of freedom in this Sn-based quasi-skutterudite. The temperature dependence of $\rho(T)$ is analyzed in terms of a power-law for resistivity pertinent to Fermi liquid picture. Giant, positive magnetoresistance (MR) $\approx$ 80$\%$ is observed in Gd$_3$Ir$_4$Sn$_{13}$ at 2~K with the application of 9~T. The giant MR and the double magnetic transition can be attributed to the quasi-cages and layered antiferromagnetic structure of Gd$_3$Ir$_4$Sn$_{13}$ vulnerable to structural distortions and/or dipolar or spin-reorientation effects. The giant value of MR observed in this class of 3:4:13 type alloys, especially in a Gd-compound, is the highlight of this work.