Crystal growth and physical properties of Ln2MGa12 (Ln=Pr, Nd, and Sm; M=Ni, Cu)

Single crystals of the Ln2MGa12 (Ln=Pr, Nd, and Sm; M=Ni, Cu) family of compounds have been synthesized using Ga flux and characterized by single crystal X-ray diffraction. These phases are isostructural to Sm2NiGa12 and crystallize in the tetragonal P4/nbm (no. 125, origin choice 2) space group, with Z=2 and lattice parameters a∼6.0 Å and c∼15.3 Å. These compounds order antiferromagnetically, and metallic behavior is observed in temperature ranges above the ordering temperature for each compound. Sm2CuGa12 shows large positive magnetoresistance ∼130% in field up to 9 T.