# Bulk properties of single crystals of the valence-unstable compound SmRh$_2$Si$_2$

## TL;DR

This study reports the synthesis and comprehensive characterization of SmRh₂Si₂ single crystals, revealing antiferromagnetic order at 64 K and discussing valence and electronic properties with implications for Kondo physics.

## Contribution

The paper provides new insights into the bulk properties and valence state of SmRh₂Si₂, including crystal growth, structural analysis, and thermodynamic measurements, highlighting its antiferromagnetic ground state.

## Key findings

- Antiferromagnetic order at T_N = 64 K
- Small Sommerfeld coefficient similar to LuRh₂Si₂
- No evidence of Kondo screening in thermodynamic data

## Abstract

We present the crystal growth as well as the structural, chemical and physical chracterization of SmRh$_2$Si$_2$ single crystals. Their ground state is antiferromagnetic, as indicated by the behaviour of the magnetic susceptibility and the specific heat at the second order phase transition observed at T$_{\rm N}$ = 64 K. The Sommerfeld coefficient is small and similar to that of LuRh$_2$Si$_2$ with $\gamma_0\approx$ J/(molK$^2$). Susceptibility measurements show no Curie-Weiss behaviour at high temperatures which is a consequence of the large Van-Vleck contribution of the excited multiplets of Sm$^{3+}$. Previous angle-resolved photoemission studies showed that at 10 K, the valence of the Sm ions is smaller than three at the surface as well as in the bulk, suggesting a possible Kondo screening of the Sm$^{3+}$ ions. This could not be observed in our thermodynamic and transport measurements.