Structural and magnetic properties of ErCo4.5Ge0.5 intermetallic compound

We report on the structural and magnetic properties of ErCo4.5Ge0.5 intermetallic compound. This phase crystallize in the hexagonal CaCu5-type structure with P6/mmm space group. Neutron powder diffraction experiments demonstrate that the Ge atoms preferentially occupy the 3g crystallographic site of the CaCu5 structure. The Ge for Co substitution induces a dramatic decrease of the magnetic ordering temperature down to 785 K. The ErCo4.5Ge0.5 compound exhibit a compensation temperature at 100 K where the magnetization of the two sublattices Er and Co cancel out. The influence of Ge for Co substitution on the magnetic properties is discussed.