Single crystal growth and physical properties of a new uranium compound URhIn$_5$

TL;DR

This study reports the synthesis of a new uranium compound URhIn$_5$, revealing its antiferromagnetic order at 98 K, and explores its electronic and magnetic properties, indicating a transition from localized to itinerant 5f electrons.

Contribution

First synthesis and characterization of URhIn$_5$, demonstrating its antiferromagnetic order and electronic behavior distinct from its nonmagnetic analogue URhGa$_5$.

Findings

URhIn$_5$ is an antiferromagnet with T_N = 98 K.

The compound exhibits a significant electronic specific heat coefficient.

Magnetic susceptibility suggests a crossover from localized to itinerant 5f electrons around 150 K.

Abstract

We have grown the new uranium compound URhIn$_5$ with the tetragonal HoCoGa$_5$-type by the In self flux method. In contrast to the nonmagnetic ground state of the isoelectronic analogue URhGa$_5$, URhIn$_5$ is an antiferromagnet with antiferromagnetic transition temperature $T_{\rm N}$ = 98 K. The moderately large electronic specific heat coefficient $\gamma$ = 50 mJ/K$^2$mol demonstrates the contribution of 5$f$ electrons to the conduction band. On the other hand, magnetic susceptibility in the paramagnetic state roughly follows a Curie-Weiss law with a paramagnetic effective moment corresponding to a localized uranium ion. The crossover from localized to itinerant character at low temperature may occur around the characteristic temperature 150 K where the magnetic susceptibility and electrical resistivity show a marked anomaly.