Crystal structure and low-temperature magnetic properties ofRmMIn3m+2compounds (M=Rh or Ir;m=1,2;R=Sm or Gd)

Abstract

We have synthesized the series of compounds $\mathrm{RM}{\mathrm{In}}_5$ and $R_{2}M{\mathrm{In}}_8$ in single crystal form, where $R=\mathrm{Sm}$ or Gd and $M=\mathrm{Rh}$ or Ir. These materials form in tetragonal derivatives of the ${\mathrm{Cu}}_3\mathrm{Au}$ structure $R{\mathrm{In}}_3$. Measurements of magnetic susceptibility, electrical resistivity, and low-temperature heat capacity are reported. These compounds order antiferromagnetically at low temperature ${(T}_N<45\mathrm{}$ K) and their low-temperature magnetic properties remain nearly unaltered compared to their ${\mathrm{SmIn}}_3$ and ${\mathrm{GdIn}}_3$ cubic relatives. The present data are compared to the magnetic properties of the isostructural (Ce,Nd) $(\mathrm{Rh},\mathrm{Ir}){\mathrm{In}}_5$ and $(\mathrm{Ce},\mathrm{Nd}{)}_2(\mathrm{Rh},\mathrm{Ir}){\mathrm{In}}_8$ compounds, and the validity of de Gennes scaling as a function of rare earth in a given structure is discussed.