Structure and properties of SmCu_6-xIn_6+x (x=0, 1, 2)

Abstract

High quality single crystals of SmCu₆In₆ were obtained from the reactions run in excess liquid indium and characterized by means of single crystal X-ray diffraction data. SmCu₆In₆ crystallizes in the YCu₆In₆ structure type, tetragonal space group I4/mmm and lattice constants are a=b=9.2036(3) Å and c=5.4232(3) Å. SmCu_6-xIn_6+x (x=0, 1, 2) compounds were obtained using arc melting and characterized using powder X-ray diffraction. Magnetic susceptibility data follow modified Curie-Weiss law behaviour above 50 K and the experimentally measured magnetic moment values in SmCu₄In₈, SmCu₅In₇ and SmCu₆In₆ are 0.83 μ_B, 1.45μ_B and 0.90 μ_B per Sm atom, respectively. SmCu₅In₇ and SmCu₆In₆ compounds show antiferromagnetic ordering at T_N=7.8 K, and no magnetic ordering was observed for SmCu₄In₈ down to 2 K. Electrical resistivity measurements show that all compounds are of metallic nature.