Magnetic and structural characteristics of the RInCu2 compounds in the Heusler L21 structure

Magnetic and structural behaviour of materials of composition RInCu₂ (R = rare earth) were investigated. All the compounds (R = La-Lu) were found to be isotypic and to crystallize with the Heusler L2₁ type structure. The magnetic behaviour of the compounds was studied in the temperature range 2–300 K. The RInCu₂ (R = Sm, Gd, Tb, Dy) compounds are antiferromagnetically ordered at low temperatures T_N = 12 K for GdInCu₂, Ce in CeInCu₂ is in a pure trivalent state. LaInCu₂ is Pauli paramagnetic and LuInCu₂ is diamagnetic. No superconductivity was observed for temperatures as low as 1.8 K. The observed magnetic properties result from indirect exchange interaction and crystal field effects and compared to the isomorphous MnInCu₂.