Symmetry analysis of k = (1/3,1/3,0) three-sublattice ordering in A14B51   compounds
  Bulk magnetic, X-ray and neutron diffraction measurements were performed on polycrystalline Tb14Ag51 in the temperature range from 1.5 K to room temperature. Its chemical Gd14Ag51 type structure corresponds to space group P6/m. Combined with group theoretical symmetry analysis, we show that the magnetic structure of this intermetallic compound is of a new k = (1/3,1/3,0) type with three magnetic Tb sublattices ordering simultaneously below TN = 27.5(5) K according to the combined irreducible representations tau4 and tau6. Here we present a general analysis of possible magnetic A ordering for k = (1/3,1/3,0) in A14B51 compounds. 
P. Fischer, V. Pomjakushin, L. Keller, A. Daoud, W. Sikora, A.   Dommann, and F. Hulliger