Weak itinerant ferromagnetism in YCo9Si4
  Weak itinerant ferromagnetism in YCo9Si4 below about 25 K is studied by means of magnetisation, specific heat, and resistivity measurements. Single crystal X-ray Rietveld refinements at room temperature reveal a fully ordered distribution of Y, Co and Si atoms within the tetragonal space group I4/mcm isostructural with LaCo9Si4. The latter exhibits itinerant electron metamagnetism with an induced moment of about 1 mu_B/f.u. above 6 T, whereas YCo9Si4 exhibits a spontaneous magnetisation M0~12 Am^2/kg at 2 K which corresponds to an ordered moment of about 1.6 mu_B/f.u. indicating weak itinerant ferromagnetism. 
H. Michor, M. El-Hagary, S. Oezcan, A. Horyn, E. Bauer, M. Reissner,   G. Hilscher, S. Khmelevskyi, P. Mohn, P.Rogl