Magnetic, Thermal, and Transport Properties of Layered Arsenides BaRu2As2 and SrRu2As2

TL;DR

This study investigates the magnetic, thermal, and transport properties of layered arsenides BaRu2As2 and SrRu2As2, revealing their metallic behavior, diamagnetism, and potential magnetic or structural transitions, contributing to understanding transition metal pnictides.

Contribution

The paper provides detailed measurements of magnetic susceptibility, resistivity, and heat capacity for BaRu2As2 and SrRu2As2, highlighting their properties within the context of related pnictides.

Findings

Both compounds exhibit metallic resistivity with high residual resistivity ratios.

BaRu2As2 shows no magnetic or structural transitions above 1.8 K.

SrRu2As2 exhibits a cusp in susceptibility around 200 K, indicating possible transitions.

Abstract

The magnetic, thermal and transport properties of polycrystalline BaRu2As2 and SrRu2As2 samples with the ThCr2Si2 structure were investigated by means of magnetic susceptibility chi(T), electrical resistivity rho(T), and heat capacity Cp(T) measurements. The temperature (T) dependence of rho indicates metallic character for both compounds with residual resistivity ratios rho(310 K)/rho(2 K) of 17 and 5 for the Ba and Sr compounds, respectively. The Cp(T) results reveal a low-T Sommerfeld coefficient gamma = 4.9(1) and 4.1(1) mJ/mol K^2 and Debye temperature \Theta_D = 271(7) K and 271(4) K for the Ba and Sr compounds, respectively. The chi (T) was found to be diamagnetic with a small absolute value for both compounds. No transitions were found for BaRu2As2 above 1.8 K. The chi(T) data for SrRu2As2 exhibit a cusp at \sim 200 K, possibly an indication of a structural and/or magnetic transition. We discuss the properties of BaRu2As2 and SrRu2As2 in the context of other ThCr2Si2-type and ZrCuSiAs-type transition metal pnictides.