Crystal structure and low-temperature magnetic properties of RmMIn3m+2 compounds (M = Rh or Ir; m=1,2; R = Sm or Gd) - art. no. 054426

We have synthesized the series of compounds RMIn5 and R2MIn8 in single crys tal form, where R = Sm or Gd and M = Rh or Ir. These materials form in tetr agonal derivatives of the Cu,Au structure RIn3. Measure ments of magnetic s usceptibility, electrical resistivity, and low-temperature heat capacity ar e reported. These compounds order antiferromagnetically at low temperature (T-N<45 K) and their low-temperature magnetic properties remain nearly unal tered compared to their SmIn3 and GdIn3 cubic relatives. The present data a re compared to the magnetic properties of the isostructural (Ce,Nd) (Rh,Ir) In-5 and (Ce,Nd)(2)(Rh,Ir)In-8 compounds, and the validity of de Gennes sca ling as a function of rare earth in a given structure is discussed.