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Four pseudo-binary RE 1-x RE' x Cu 2 In systems were investigated at 870 K using X-ray diffraction: (La,Y)Cu 2 In, (La,Ce)Cu 2 In, (La,Gd)Cu 2 In, and (Y,Gd)Cu 2 In. The formation of continuous solid solutions with MnCu 2 Al-type structure was observed in all cases. In agreement with the atomic radii of the rare-earth elements, the composition dependencies of the unit cell parameters of these Heusler phases exhibit a monotonous decrease when La is replaced by Y, Ce, or Gd, but a slight increase when Y is replaced by Gd. An investigation of the magnetic properties of single-phase alloys belonging to the La 1-x Gd x Cu 2 In solid solution (x = 0.1-0.4) showed Curie-Weiss paramagnetism with predominantly antiferromagnetic interactions between Gd 3+ ions, but no magnetic ordering down to 1.72 K.

The new ternary indide Ca 16 Ni 173.14 In 62.61 was synthesized from the elements by arc-melting and its crystal structure was determined by means of X-ray single crystal diffraction. The compound crystallizes in its own structure type: space group P2 1 /m (No. 11), Z = 1, mP254, a = 1.5374(3) nm, b = 1.6565(9) nm, c = 1.5911(2) nm, β = 115.434(7)º, wR2 = 0.0715, 6674 F 2 values, 691 variable parameters. The compound Ca 16 Ni 173.14 In 62.61 exists only in as-cast samples and decomposes during annealing at 1070 K with the formation of CaNi 9-x In 2+x. In the structure of Ca 16 Ni 173.14 In 62.61 the nickel atoms build complex puckered twodimensional Ni-slabs, which are interconnected along the [110] direction by indium atoms into a [Ni 173.14 In 62.61 ] network, in the cavities of which the calcium atoms are situated.