Enhanced electrical resistivity before N\'eel order in the metals, RCuAs$_2$ (R= Sm, Gd, Tb and Dy

TL;DR

This study investigates unusual electrical resistivity behavior in RCuAs$_2$ compounds, revealing a resistivity minimum above the Néel temperature in some rare-earth variants, challenging existing magnetic and electronic theories.

Contribution

It reports a novel resistivity anomaly in RCuAs$_2$ compounds that varies with 4f hybridization, providing new insights into magnetic and electronic interactions in these materials.

Findings

Resistivity minimum observed above Néel temperature in Sm, Gd, Tb, Dy compounds

Minimum is suppressed in compounds with stronger 4f hybridization

Findings challenge existing theories of magnetic resistivity behavior

Abstract

We report an unusual temperature (T) dependent electrical resistivity($\rho$) behavior in a class of ternary intermetallic compounds of the type RCuAs$_2$ (R= Rare-earths). For some rare-earths (Sm, Gd, Tb and Dy) with negligible 4f-hybridization, there is a pronounced minimum in $\rho$(T) far above respective N\'eel temperatures (T$_N$). However, for the rare-earths which are more prone to exhibit such a $\rho$(T) minimum due to 4f-covalent mixing and the Kondo effect, this minimum is depressed. These findings, difficult to explain within the hither-to-known concepts, present an interesting scenario in magnetism.