Results for “Co-Ni-Si”

DOE OSTI2020

Materials Data on CoSi4Ni by Materials Project

CoNiSi4 is half-Heusler-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Co4+ is bonded in a body-centered cubic geometry to eight Si2- atoms. There are two shorter (2.30 Å) and six longer (2.32 Å) Co–Si bond lengths. Ni4+ is bonded in a body-centered cubic geometry to eight Si2- atoms. There are six shorter (2.35 Å) and two longer (2.37 Å) Ni–Si bond lengths. There are two inequivalent Si2- sites. In the first Si2- site, Si2- is bonded to three equivalent Co4+, one Ni4+, and six Si2- atoms to form a mixture of distorted edge, face, and corner-sharing SiCo3Si6Ni tetrahedra. There are three shorter (2.66 Å) and three longer (2.70 Å) Si–Si bond lengths. In the second Si2- site, Si2- is bonded to one Co4+, three equivalent Ni4+, and three equivalent Si2- atoms to form a mixture of distorted edge, face, and corner-sharing SiCoSi3Ni3 tetrahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on CoSi4Ni3 by Materials Project

CoNi3Si4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Co2+ is bonded to six Si2- atoms to form distorted CoSi6 pentagonal pyramids that share corners with twelve NiSi6 octahedra, edges with two equivalent CoSi6 pentagonal pyramids, edges with four equivalent NiSi6 pentagonal pyramids, and faces with two equivalent NiSi6 octahedra. The corner-sharing octahedra tilt angles range from 45–59°. There are a spread of Co–Si bond distances ranging from 2.27–2.35 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 octahedra that share corners with four equivalent CoSi6 pentagonal pyramids, corners with eight equivalent NiSi6 pentagonal pyramids, edges with six NiSi6 octahedra, and faces with two equivalent CoSi6 pentagonal pyramids. There are a spread of Ni–Si bond distances ranging from 2.28–2.39 Å. In the second Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 pentagonal pyramids that share corners with twelve NiSi6 octahedra, edges with two equivalent NiSi6 pentagonal pyramids, edges with four equivalent CoSi6 pentagonal pyramids, and faces with two equivalent NiSi6 octahedra. The corner-sharing octahedra tilt angles range from 45–60°. There are a spread of Ni–Si bond distances ranging from 2.27–2.39 Å. In the third Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 octahedra that share corners with four equivalent NiSi6 pentagonal pyramids, corners with eight equivalent CoSi6 pentagonal pyramids, edges with six NiSi6 octahedra, and faces with two equivalent NiSi6 pentagonal pyramids. There are a spread of Ni–Si bond distances ranging from 2.31–2.42 Å. There are four inequivalent Si2- sites. In the first Si2- site, Si2- is bonded in a 8-coordinate geometry to one Co2+, five Ni2+, and two equivalent Si2- atoms. Both Si–Si bond lengths are 2.60 Å. In the second Si2- site, Si2- is bonded in a 8-coordinate geometry to one Co2+, five Ni2+, and two equivalent Si2- atoms. Both Si–Si bond lengths are 2.68 Å. In the third Si2- site, Si2- is bonded in a 8-coordinate geometry to two equivalent Co2+, four Ni2+, and two equivalent Si2- atoms. In the fourth Si2- site, Si2- is bonded in a 8-coordinate geometry to two equivalent Co2+, four Ni2+, and two equivalent Si2- atoms.

36 MATERIALS SCIENCE↗