Low temperature properties of some RIn3 compounds

The low temperature heat capacity of ErIn3 has been studied because of its potential as a regenerator material. Slight variations from stoichiometry and plastic deformation have been shown to affect the heat capacity of ErIn3. The (HoxEr1−x)In3 system has been studied in detail revealing that the lattice parameter varies linearly as a function of x, while the Néel temperatures vary with a slight departure from linearity. An analysis of the concentration dependence of the Néel temperature in the (HoxEr1−x)In3 system indicates that when the rare earth metal size is within 5.65% of the indium radius, a narrow solid solution region forms on the indium-rich side of the RIn3 phase. A high-resolution X-ray powder diffraction study does not reveal a structural distortion in ErIn3, or (Ho0.25In0.75)In3, or HoIn3. Rare earth substitutions (R = Y, Ce, Pr, and Dy) for the Er in (RxEr1−x)In3 shift the Néel temperature and may have a significant effect on the heat capacity, depending on the rare earth metal.