VERY WEAK ITINERANT FERROMAGNETISM IN THE NEW LU3CO8-XSN4 COMPOUND (X=0.23)

Abstract The crystal structure of the new compound Lu 3 Co 8− x Sn 4 ( x = 0.23) was determined by using a single-crystal diffraction method. The structure of Lu 3 Co 8− x Sn 4 is a distorted variant of the BaLi 4 structure type: space group P6 3 mc, a = 8.746(3) A , c = 7.432(2) A , Z = 2. The coordination number of the lutetium atom is 18; for the tin and cobalt atoms the coordination polyhedra are either distorted icosahedra or trigonal prisms. The magnetic properties of Lu 3 Co 8− x Sn 4 are presented and discussed. This compound is a typical very weak itinerant ferromagnet with T c = 63 K and a Co moment of 0.19 μ B at 4 K, whereas the effective paramagnetic moment reaches 1.86 μ B Co .