The structure and physical properties of CuMPd6 (M = Ti, V, Mn and Fe) ternary alloys

In situ X-ray diffraction and magnetic susceptibility measurements were performed to determine the structure, thermal and magnetic properties of the ternary alloys CuMPd6 (M = Ti, V, Mn and Fe). The X-ray diffraction experiments of the polycrystalline specimens annealed at 1273 K have shown that a single phase (A1-type face-centered cubic (fcc) structure) is formed at this stoichiometric composition up to a temperature of 1178 K. The integrated intensity data obtained from the diffraction experiments were utilized to determine the lattice parameters, Debye temperatures (ΘD), the mean linear thermal expansion (MLTE) and the coefficients of thermal expansion (α(T)). The lattice parameters showed a positive deviation from the Vegard's law, whereas the Debye temperatures were found to be of the same order as for CuPd3 alloy. The contribution of the static displacements to the temperature factors was found to be nearly zero for the four alloys. The linear thermal expansion follows the classical Grüneisen relationship in these alloys. The trend of magnetic properties in these alloys was observed to be similar to that for CuMPt6 alloys (see text) i.e. paramagnetic – spin glass – ferromagnetic with the increasing atomic number of the metal M. The results have been discussed by comparing with those given in literature.