Abstract
The new intermetallic compounds Sr2ZnP2, Sr2
ZnAs2,
A2ZnSb2 and A2ZnBi2 (A = Sr, Eu) have been synthesized from the
corresponding elements through high-temperature reactions using the
flux-growth method. Their structures have been established by singlecrystal
and powder X-ray diffraction. In all cases, the X-ray diffraction
patterns can be successfully indexed based on hexagonal cells in the
space group P63/mmc (no. 194) with lattice parameters in the range a
= 4.31–4.73 Å and c = 7.9–8.55 Å. The average structure can be described
in the ZrBeSi type (Pearson symbol hP6; 3 unique positions) with defects on the zinc site – structure refinements indicate that every second zinc position is vacant, i.e., their formula unit is AZn1–xPn with x = 0.5 (A = Sr, Eu; Pn = P, As, Sb, Bi). No stoichiometry breadth was observed, which could imply that a super-structure with a long-range order of the zinc vacancies is plausible and evidence for such was
sought using electron diffraction. The results from these experiments,
as well as magnetic susceptibility measurements and band structure
calculations using the LMTO code are also discussed.