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6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Dy(CrGe)2 by Materials Project

Dy(CrGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Dy is bonded in a 8-coordinate geometry to eight equivalent Ge atoms. All Dy–Ge bond lengths are 3.04 Å. Cr is bonded to four equivalent Ge atoms to form a mixture of edge and corner-sharing CrGe4 tetrahedra. All Cr–Ge bond lengths are 2.45 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Dy, four equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.58 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrGe by Materials Project

CrGe crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Cr is bonded in a 7-coordinate geometry to seven equivalent Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.41–2.66 Å. Ge is bonded in a 7-coordinate geometry to seven equivalent Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(CrGe)6 by Materials Project

Ho(CrGe)6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ho is bonded to eight Ge atoms to form distorted edge-sharing HoGe8 hexagonal bipyramids. There are two shorter (2.88 Å) and six longer (2.95 Å) Ho–Ge bond lengths. Cr is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Cr–Ge bond distances ranging from 2.55–2.68 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 12-coordinate geometry to three equivalent Ho and six equivalent Cr atoms. In the second Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Cr atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to one Ho, six equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.57 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np(CrGe)2 by Materials Project

Np(CrGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np is bonded in a 8-coordinate geometry to eight equivalent Ge atoms. All Np–Ge bond lengths are 3.03 Å. Cr is bonded to four equivalent Ge atoms to form a mixture of edge and corner-sharing CrGe4 tetrahedra. All Cr–Ge bond lengths are 2.45 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Np, four equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.56 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th(CrGe)2 by Materials Project

ThCr2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Th is bonded in a 8-coordinate geometry to eight equivalent Cr and eight equivalent Ge atoms. All Th–Cr bond lengths are 3.38 Å. All Th–Ge bond lengths are 3.23 Å. Cr is bonded to four equivalent Th and four equivalent Ge atoms to form a mixture of edge, face, and corner-sharing CrTh4Ge4 tetrahedra. All Cr–Ge bond lengths are 2.48 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Th, four equivalent Cr, and one Ge atom. The Ge–Ge bond length is 2.63 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Electronic and magnetic properties of iridium-based novel Heusler alloys

We report half-metallicity and magnetism including exchange splitting are the most significant physical parameters to predict and design a candidate material for spintronic applications. We report here an ab-initio investigation on chemical formation and dynamical stability along with electronic structure and magnetic properties of Ir 2 Cr (Si, Ge) and IrRhCr (Si, Ge) Heusler alloys. The negative formation and cohesive energies with positive phonon dispersions confirm the stabilities of these alloys. Electronic structure calculations reveal that Ir 2 Cr (Si, Ge) and IrRhCrSi alloys are half-metallic ferromagnets with unprecedented exchange splitting. In addition, IrRhCrGe also shows semi-metallic nature. All of these materials follow Slater Pauling rule with large magnetic moments and 100% spin-polarization. With Cr bearing the majority of the local magnetic moment and exchange splitting, a ferromagnetic state is more stable than a nonmagnetic state. The electronic charge distribution and population analysis confirm mixed ionic and covalent bonding. The magnetocrystalline anisotropy energy, with the easy magnetization along the [1 1 1] direction, is significantly high in Ir 2 CrGe. Elastic constants such as shear (G), bulk (B), Young’s moduli, and Poisson’s ratio indicate that the IrRhCrSi and IrRhCrGe alloys are mechanically stable, and Ir 2 CrSi and Ir 2 CrGe are mechanically unstable. The Pugh’s (B/G) and Poisson’s ratios confirm that the stable alloys are ductile.

36 MATERIALS SCIENCE↗