Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Co-Ge”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Electronic Structure and Spin Correlations in Novel Magnetic Structures

The research has advanced understanding of the interrelation between the crystal structure and magnetism in several materials which are or can be of interest for the development of improved, specialized or more cost-effective permanent magnets, as well as in selected materials for biomedical and catalytic applications. Fundamental aspects of ferromagnetism were investigated for Mn-Ge, Co-V and Co-Ge nanoclusters and for melt-spun Co-Sn alloys. New solution-chemistry synthesis methods were designed and tested for Fe-Pt, Fe3C and Fe3O4 nanoparticles. Off-stoichiometric Laves phases in the Fe-Si-Zr, Fe-Nb and Fe-Ta systems, as well as Fe5(Si,Ge)B2 compounds were assessed as new rare-earth-free permanent magnet materials; all except the Fe-Si-Zr Laves phases were found to be promising enough to merit a further exploration. A new method for manufacturing rare-earth-free magnets based on the MnBi compound was developed; by purposely avoiding oxidation-sensitive fine single-crystalline powders, the new method yields magnets with a 50% larger energy storage capacity. Studies of rare-earth-lean permanent-magnet materials (lean compared to the currently predominant Nd-Fe-B materials) were focused on the tetragonal compound of the ThMn12 structure type and included both discovery and characterization of new formulations and exploration of new fabrication/processing techniques. Among the most significant achievements were successful preparation of a vanadium-lean SmFe11V compound, the first observation of thermomechanically induced texture in nanocrystalline Sm(Fe,V)12 alloys, and a breakthrough reduction-diffusion synthesis of Sm1-xZrx(Fe0.8Co0.2)11.2Ti0.8 single-crystal particles with a coercivity as high as 12.6 kOe. Several experiments aimed at improvement of the Nd-Fe-B magnet have also been undertaken including a five-fold increase of the coercivity through a grain-boundary diffusion treatment of a Nd10Fe84B6 nanocrystalline alloy.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoGe by Materials Project

CoGe crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Co is bonded in a 7-coordinate geometry to seven equivalent Ge atoms. There are a spread of Co–Ge bond distances ranging from 2.38–2.61 Å. Ge is bonded in a 7-coordinate geometry to seven equivalent Co atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co2Ge by Materials Project

Co2Ge crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Co sites. In the first Co site, Co is bonded to six equivalent Co and five equivalent Ge atoms to form a mixture of distorted face and corner-sharing CoCo6Ge5 trigonal bipyramids. All Co–Co bond lengths are 2.63 Å. There are three shorter (2.31 Å) and two longer (2.51 Å) Co–Ge bond lengths. In the second Co site, Co is bonded in a 8-coordinate geometry to eight Co and six equivalent Ge atoms. Both Co–Co bond lengths are 2.51 Å. All Co–Ge bond lengths are 2.63 Å. Ge is bonded in a 11-coordinate geometry to eleven Co atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoGe by Materials Project

CoGe is Modderite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Co sites. In the first Co site, Co is bonded in a 6-coordinate geometry to four Co and six Ge atoms. There are two shorter (2.46 Å) and two longer (2.58 Å) Co–Co bond lengths. There are four shorter (2.40 Å) and two longer (2.46 Å) Co–Ge bond lengths. In the second Co site, Co is bonded in a 6-coordinate geometry to four Co and six Ge atoms. Both Co–Co bond lengths are 2.59 Å. There are four shorter (2.38 Å) and two longer (2.44 Å) Co–Ge bond lengths. In the third Co site, Co is bonded in a 6-coordinate geometry to two Co and six Ge atoms. There are a spread of Co–Ge bond distances ranging from 2.38–2.52 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 6-coordinate geometry to six Co atoms. In the second Ge site, Ge is bonded in a 6-coordinate geometry to six Co atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co5Ge7 by Materials Project

Co5Ge7 crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. there are two inequivalent Co sites. In the first Co site, Co is bonded in a 9-coordinate geometry to five Ge atoms. There are one shorter (2.23 Å) and four longer (2.37 Å) Co–Ge bond lengths. In the second Co site, Co is bonded in a 6-coordinate geometry to six Ge atoms. There are a spread of Co–Ge bond distances ranging from 2.46–2.84 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a single-bond geometry to one Co and four equivalent Ge atoms. All Ge–Ge bond lengths are 2.95 Å. In the second Ge site, Ge is bonded in a 10-coordinate geometry to four equivalent Co and six Ge atoms. There are a spread of Ge–Ge bond distances ranging from 2.51–2.93 Å. In the third Ge site, Ge is bonded in a 10-coordinate geometry to five Co and five Ge atoms. Both Ge–Ge bond lengths are 2.72 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoGe2 by Materials Project

CoGe2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Co is bonded in a 8-coordinate geometry to one Co and eight Ge atoms. The Co–Co bond length is 2.55 Å. There are four shorter (2.48 Å) and four longer (2.49 Å) Co–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 7-coordinate geometry to four equivalent Co and one Ge atom. The Ge–Ge bond length is 2.55 Å. In the second Ge site, Ge is bonded to four equivalent Co atoms to form a mixture of distorted edge and corner-sharing GeCo4 tetrahedra.

36 MATERIALS SCIENCE↗