New Yb5Sb3-type R5TxX3-x compounds (R = Gd-Er, T = Fe-Cu, X = Sb, Bi)

A powder X-ray diffraction investigation of new Yb5Sb3-type R5TBi3-x and R5TxSb3-x solid solutions is reported. Substitution of Sb or Bi for transition metals leads to the distortion of the initial unit cell. The distortion of the initial unit cell is anisotropic: the cell parameter a increases while the cell parameters b and c decrease with decreasing unit cell volume. The Dy5CoBi2, Ho5CoBi2 and Er5CoBi2 compounds demonstrate a magnetic transition at 34(4), 25(4) and 20(2) K, respectively. The temperature of the magnetic transition of these solid solutions are close to the Dy5Bi3, Ho5Bi3 and Er5Bi3 compounds, respectively. (c) 2004 Elsevier B.V. All rights reserved.