Structure and Magnetic Properties of GdPt2In and GdPt2Sn

The platinum-rich intermetallic compounds GdPt2In and GdPt2Sn were synthesized by arc-melting of the elements and subsequent annealing. The structures were refined from single crystal X-ray diffractometer data: ZrPt2Al type, space group P6(3)/mmc, a = 455.1(1), c = 899.3(3) pm, wR2 = 0.0361, 166 F-2 values, 9 variables for GdPt2In, and a = 453.2(1), c = 906.5(2) pm, wR2 = 0.0915, 166 F-2 values, 9 variables for GdPt2Sn. The platinum and indium (tin) atoms build up three-dimensional [Pt2In] and [Pt2Sn] networks with short Pt-In (Pt-Sn) distances and Pt-2 dumb-bells (290 and 297 pm in GdPt2In and GdPt2Sn). The gadolinium atoms have coordination number 14 with 8 Pt and 6 In (Sn) neighbors. Magnetic susceptibility measurements on GdPt2In show Curie-Weiss behavior with an experimental magnetic moment of 8.06(2) mu(B)/Gd atom. GdPt2In orders ferromagnetically at 27.7(2) K.