Low-temperature physical properties of GdCoIn$_5$

TL;DR

This study combines experimental measurements and theoretical calculations to analyze the low-temperature magnetic, thermal, and electronic properties of GdCoIn$_5$, revealing a second-order phase transition likely due to antiferromagnetic ordering.

Contribution

It provides a comprehensive experimental and theoretical analysis of GdCoIn$_5$'s low-temperature properties, including magnetic interactions and phase transition characterization.

Findings

Second-order phase transition at 30 K observed.

Magnetic moments localized at Gd ions confirmed.

Theoretical models accurately reproduce experimental data.

Abstract

A comprehensive experimental and theoretical study of the low temperature properties of GdCoIn$_5$ was performed. Specific heat, thermal expansion, magnetization and electrical resistivity were measured in good quality single crystals down to $^4$He temperatures. All the experiments show a second-order-like phase transition at 30 K probably associated with the onset of antiferromagnetic order. Total energy GGA+U calculations indicate a ground state with magnetic moments localized at the Gd ions and allowed a determination of the Gd-Gd magnetic interactions. Band structure calculations of the electron and phonon contributions to the specific heat and Quantum Monte Carlo calculations of the magnetic contributions to the thermodynamic quantities reproduce quite well the experimental data.