Crystal structures nickel arsenide

A limited number of T2-B2 systems at the equiatomic composition MN crystallize not with the nickel arsenide structure but with the so-called B 31 arrangement. This structure is of lower symmetry than that of nickel arsenide but is in fact closely related to it, and can be derived from it by a small displacement of the atoms. The systems marked with an obelisk in table 13.05 show the. B31 structure. 

The intermetallic compounds MnAs, MnSb, and MnBi crystallize with a nickel arsenide-type structure, and they have many features in common regarding their structure and nature of physical properties. At room temperature, all these compounds are ferromagnetic. The Curie point of manganese arsenide is 45°C of MnSb and MnBi it is 314 and 360°C, respectively. Their ferromagnetism is due to the uncompensated spins of the 3d electron shells of the manganese atoms, located at the crystal lattice points with the coordinates 0, 0, 0 and 0, 0, i. 

The octahedrons surrounding the Ni " " ions in NiAs, on the other hand, are edge-shared in one direction while face-shared in another, leading to a layered structure with an ABABAB-type repeating motif. The following molecules all crystallize in the nickel arsenide structure TiS, TiSe, TiTe, CrS, CrSe, CrTe, CrSb, NiS, NiSe, NiTe, NiSb, and NiSn. 

---