LaNiGe with non‐centrosymmetric LaPtSi type structure

The equiatomic germanide LaNiGe was synthesized from the elements by arc-melting and subsequent annealing at 1173 K for 14 days. Its non-centrosymmetric LaPtSi type structure was refined from single-crystal X-ray diffractometer data: I4(1)md, a = 420.80(6), c = 1440.3(3) pm, wR = 0.0477, 284 F-2 values and 14 variables. The nickel and germanium atoms build up a three-dimensional [NiGe](delta-) polyanionic network (2 x 241 and 1 x 242 pm Ni-Ge) in which the lanthanum atoms fill cavities with coordination number 12. This picture of chemical bonding is supported by an evaluation of the electron localization function. Physical properties of LaNiGe were studied by means of magnetic susceptibility, magnetization, specific heat and electrical resistivity measurements. The compound was found to be a Pauli paramagnet with a molar magnetic susceptibility of about chi = 1.6 x 10(-4) emu center dot mol(-1)center dot Oe(-1). The temperature dependence of the electrical resistivity shows Bloch-Gruneissen-Mott behavior indicating the metallic character of LaNiGe, which is in full agreement with the results of electronic structure and density of states calculations. No superconducting transition was observed in the temperature regime down to 1.72 K.