Crystal-field-induced magnetic frustration in NdMIn5 and Nd2MIn8 (M=Rh, Ir) antiferromagnets

Abstract

We have synthesized the series of compounds $\mathrm{Nd}M{\mathrm{In}}_5$ and ${\mathrm{Nd}}_{2}M{\mathrm{In}}_8$ in single crystal form, where $M=\mathrm{Rh}$ or Ir. These materials form in tetragonal derivatives of the ${\mathrm{Cu}}_3\mathrm{Au}$-structure NdIn${}_3$ compound. Measurements of magnetic susceptibility, electrical resistivity, and low-temperature heat capacity are reported. These compounds order antiferromagnetically at low temperature ${(T}_N<14\mathrm{}\hspace{0.5em}\mathrm{K})$ and the evolution of their magnetic properties depends on the crystal-field ground-state configuration. Comparison between the present data and magnetic properties of the isostrucutural new heavy fermion compounds $\mathrm{Ce}(\mathrm{Rh},\mathrm{Ir}){\mathrm{In}}_5$ and ${\mathrm{Ce}}_2(\mathrm{Rh},\mathrm{Ir}){\mathrm{In}}_8$ suggests that crystal field effects and magnetic anisotropy should be taken into account to understand the rich phase diagram of these compounds.