Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “LaWN3”

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 OSTI2020

Materials Data on LaWN3 by Materials Project

LaWN3 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are four shorter (2.51 Å) and four longer (2.85 Å) La–N bond lengths. W6+ is bonded in a 5-coordinate geometry to five N3- atoms. There is one shorter (1.81 Å) and four longer (2.01 Å) W–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to two equivalent La3+ and two equivalent W6+ atoms to form a mixture of distorted edge and corner-sharing NLa2W2 trigonal pyramids. In the second N3- site, N3- is bonded in a distorted single-bond geometry to four equivalent La3+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaWN3 by Materials Project

LaWN3 crystallizes in the trigonal R3c space group. The structure is three-dimensional. La3+ is bonded in a 12-coordinate geometry to six equivalent N3- atoms. There are three shorter (2.56 Å) and three longer (2.65 Å) La–N bond lengths. W6+ is bonded to six equivalent N3- atoms to form corner-sharing WN6 octahedra. The corner-sharing octahedral tilt angles are 22°. There are three shorter (1.90 Å) and three longer (2.20 Å) W–N bond lengths. N3- is bonded in a 4-coordinate geometry to two equivalent La3+ and two equivalent W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaWN3 by Materials Project

LaWN3 crystallizes in the trigonal R3m space group. The structure is three-dimensional. La3+ is bonded in a 12-coordinate geometry to nine equivalent N3- atoms. There are three shorter (2.59 Å) and six longer (2.87 Å) La–N bond lengths. W6+ is bonded to six equivalent N3- atoms to form distorted corner-sharing WN6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are three shorter (1.89 Å) and three longer (2.19 Å) W–N bond lengths. N3- is bonded in a 5-coordinate geometry to three equivalent La3+ and two equivalent W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaWN3 by Materials Project

LaWN3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are a spread of La–N bond distances ranging from 2.55–2.73 Å. In the second La3+ site, La3+ is bonded in a 10-coordinate geometry to ten N3- atoms. There are a spread of La–N bond distances ranging from 2.46–3.04 Å. W6+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of W–N bond distances ranging from 1.82–2.51 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to two equivalent La3+ and two equivalent W6+ atoms to form distorted NLa2W2 tetrahedra that share corners with four equivalent NLa4W2 octahedra, corners with two equivalent NLa2W2 tetrahedra, and an edgeedge with one NLa4W2 octahedra. The corner-sharing octahedra tilt angles range from 12–21°. In the second N3- site, N3- is bonded to four La3+ and two equivalent W6+ atoms to form distorted NLa4W2 octahedra that share corners with four equivalent NLa2W2 tetrahedra, edges with two equivalent NLa4W2 octahedra, and an edgeedge with one NLa2W2 tetrahedra. In the third N3- site, N3- is bonded in a 1-coordinate geometry to four La3+ and two equivalent W6+ atoms. In the fourth N3- site, N3- is bonded in a 4-coordinate geometry to two La3+ and two equivalent W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaWN3 by Materials Project

LaWN3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. La3+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of La–N bond distances ranging from 2.45–2.63 Å. W6+ is bonded to five N3- atoms to form a mixture of distorted corner and edge-sharing WN5 trigonal bipyramids. There are a spread of W–N bond distances ranging from 1.81–2.12 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to three equivalent La3+ and one W6+ atom to form a mixture of distorted corner and edge-sharing NLa3W tetrahedra. In the second N3- site, N3- is bonded to one La3+ and three equivalent W6+ atoms to form a mixture of distorted corner and edge-sharing NLaW3 tetrahedra. In the third N3- site, N3- is bonded in a distorted trigonal planar geometry to two equivalent La3+ and one W6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Synthesis of LaWN 3 nitride perovskite with polar symmetry

Perovskite structured materials have a variety of uses as photovoltaics, capacitors, and micromechanical actuators, along with other applications. Oxides, halides, and chalcogenides all have large numbers of perovskite structured materials. Examples of perovskite nitrides are conspicuously absent, but Talley et al managed to synthesize one (see the Perspective by Hong). Lanthanum tungsten nitride in the perovskite structure turns out to be piezoelectric, which is ideal for a variety of applications. Perovskite structured nitrides are very attractive because they could easily integrate with the large number of nitride-based semiconducting devices already in use.

36 MATERIALS SCIENCE↗