Structure and magnetism of GdRuGe

摘要

The ternary germanide GdRuGe was synthesized from the elements by arc-melting and its structure was refined from single crystal X-ray diffractometer data: TiNiSi type, space group Prima, a = 709.3(2), b = 442.9(1), c = 723.3(2) pm, wR2 = 0.0491, 547 F-2 values, 20 variables. The ruthenium and germanium atoms build up a three-dimensional RuGe polyanionic network with strongly distorted, corner-sharing RuGe4/4 tetrahedra with Ru-Ge distances ranging from 252 to 260 pm. The gadolinium atoms fill voids with coordination number 16 within the RuGe network. GdRuGe orders ferromagnetically around 70 K and exhibits complete saturation of the Gd moments at 5 K in the isothermal magnetization measurements. The compound also exhibits a moderate magnetocaloric effect, Delta S = 2 J/mol K (for Delta H = 30 kOe and T = Tc = 70 K).