Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “NaMnO2”

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.

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaMnO2 by Materials Project

NaMnO2 is Caswellsilverite structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to six equivalent O2- atoms to form NaO6 octahedra that share corners with six equivalent MnO6 octahedra, edges with six equivalent NaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are four shorter (2.39 Å) and two longer (2.44 Å) Na–O bond lengths. Mn3+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share corners with six equivalent NaO6 octahedra, edges with six equivalent NaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are four shorter (1.97 Å) and two longer (2.44 Å) Mn–O bond lengths. O2- is bonded to three equivalent Na1+ and three equivalent Mn3+ atoms to form a mixture of distorted corner and edge-sharing ONa3Mn3 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMnO2 by Materials Project

NaMnO2 is H-Phase structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Na1+ is bonded to six equivalent O2- atoms to form distorted NaO6 pentagonal pyramids that share corners with six equivalent MnO6 octahedra, edges with six equivalent MnO6 octahedra, and edges with six equivalent NaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 12°. All Na–O bond lengths are 2.44 Å. Mn3+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share corners with six equivalent NaO6 pentagonal pyramids, edges with six equivalent MnO6 octahedra, and edges with six equivalent NaO6 pentagonal pyramids. All Mn–O bond lengths are 2.09 Å. O2- is bonded to three equivalent Na1+ and three equivalent Mn3+ atoms to form a mixture of edge, corner, and face-sharing ONa3Mn3 octahedra. The corner-sharing octahedra tilt angles range from 0–43°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaMnO2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2023

Dark field X-ray microscopy below liquid-helium temperature: The case of NaMnO 2

Dark field X-ray microscopy (DFXM) is an experimental technique employed to investigate material properties by probing their ‘mesoscale,’ or microscale structures, in a bulk-sensitive manner using hard X-rays at synchrotron radiation sources. However, challenges remain when it comes to applications of this technique to examine low-temperature phenomena in quantum materials, which exhibit complex phase transitions at cryogenic temperatures. One such material is NaMnO 2 , which hosts an antiferromagnetic transition at 45 K that is suspected to coincide with local structural transitions from its majority monoclinic phase to nanoscale triclinic domains. Direct observation of local heterogeneities and this effect at low temperatures in NaMnO 2 is an important step in understanding this material and serves as an ideal candidate study for expanding the DFXM experimental design space. This paper details a foundational high-resolution DFXM study, down to liquid-helium temperature and below, conducted to explore phase transitions in NaMnO 2 . In conclusion, the outlined experiment ushers in the evaluation of other functional materials at low temperatures using this technique.

36 MATERIALS SCIENCE↗