Abstract
The title compounds can be synthesized in quantitative yields by
arc-melting of stoichiometric amounts of HfSb2, Hf and one of the 3d
metals V, Cr, Mn, Fe, Co, Ni, and Cu. These antimonides crystallize in a
substitution variant of the W5Si3 type, in which one position is
statistically mixed, occupied by the 3d metal atom M or the Sb2 atom in
different ratios. Within the Linear (M,Sb) chain, the M:Sb ratio may
vary between 3:1 and 2:3. According to calculations of the electronic
structures of Hf10MdeltaSb6-delta with delta = 1, these phases are
metallic compounds stabilized by strong Hf-Hf, HF-M, and Hf-Sb bonds,
and to a smaller extent by bonding interactions within the linear (M,Sb)
chain. The metallic character was confirmed by measurements of the
electrical resistivity and the magnetism of selected samples. Whereas
Pauli paramagnetism was observed experimentally for M = V, Co, and Ni,
Hf10FeSb5 is apparently the only phase with localized magnetic moments
and magnetic coupling. This is in agreement with the magnetic ground
state obtained solely for the ordered structure model of Hf10FeSb5 with
spin-polarized calculation within the local spin density approximation.
