DOE OSTI2020
FePt6Ni is Uranium Silicide-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Fe3+ is bonded to twelve Pt+0.83- atoms to form FePt12 cuboctahedra that share corners with four equivalent FePt12 cuboctahedra, corners with eight equivalent NiPt12 cuboctahedra, edges with twenty-four PtNi4Pt8 cuboctahedra, faces with two equivalent NiPt12 cuboctahedra, faces with four equivalent FePt12 cuboctahedra, and faces with twelve PtFe4Pt8 cuboctahedra. There are eight shorter (2.76 Å) and four longer (2.77 Å) Fe–Pt bond lengths. There are three inequivalent Pt+0.83- sites. In the first Pt+0.83- site, Pt+0.83- is bonded to four equivalent Fe3+ and eight equivalent Pt+0.83- atoms to form PtFe4Pt8 cuboctahedra that share corners with twelve PtFe4Pt8 cuboctahedra, edges with eight equivalent NiPt12 cuboctahedra, edges with sixteen equivalent PtFe2Ni2Pt8 cuboctahedra, faces with four equivalent FePt12 cuboctahedra, and faces with fourteen PtFe4Pt8 cuboctahedra. All Pt–Pt bond lengths are 2.76 Å. In the second Pt+0.83- site, Pt+0.83- is bonded to eight equivalent Pt+0.83- and four equivalent Ni2+ atoms to form PtNi4Pt8 cuboctahedra that share corners with twelve PtFe4Pt8 cuboctahedra, edges with eight equivalent FePt12 cuboctahedra, edges with sixteen equivalent PtFe2Ni2Pt8 cuboctahedra, faces with four equivalent NiPt12 cuboctahedra, and faces with fourteen PtFe4Pt8 cuboctahedra. All Pt–Pt bond lengths are 2.77 Å. All Pt–Ni bond lengths are 2.77 Å. In the third Pt+0.83- site, Pt+0.83- is bonded to two equivalent Fe3+, eight Pt+0.83-, and two equivalent Ni2+ atoms to form distorted PtFe2Ni2Pt8 cuboctahedra that share corners with twelve equivalent PtFe2Ni2Pt8 cuboctahedra, edges with four equivalent FePt12 cuboctahedra, edges with four equivalent NiPt12 cuboctahedra, edges with sixteen PtFe4Pt8 cuboctahedra, faces with two equivalent FePt12 cuboctahedra, faces with two equivalent NiPt12 cuboctahedra, and faces with fourteen PtFe4Pt8 cuboctahedra. All Pt–Pt bond lengths are 2.77 Å. Both Pt–Ni bond lengths are 2.77 Å. Ni2+ is bonded to twelve Pt+0.83- atoms to form NiPt12 cuboctahedra that share corners with four equivalent NiPt12 cuboctahedra, corners with eight equivalent FePt12 cuboctahedra, edges with twenty-four PtFe4Pt8 cuboctahedra, faces with two equivalent FePt12 cuboctahedra, faces with four equivalent NiPt12 cuboctahedra, and faces with twelve PtNi4Pt8 cuboctahedra.