Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “CoSe”

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.

Materials Data on CoSe by Materials Project

CoSe is lead oxide structured and crystallizes in the tetragonal P4/nmm space group. The structure is two-dimensional and consists of one CoSe sheet oriented in the (0, 0, 1) direction. Co2+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.31 Å. Se2- is bonded in a 4-coordinate geometry to four equivalent Co2+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on CoSe by Materials Project

CoSe is Molybdenum Carbide MAX Phase-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Co2+ is bonded to six equivalent Se2- atoms to form a mixture of corner, edge, and face-sharing CoSe6 octahedra. The corner-sharing octahedral tilt angles are 50°. All Co–Se bond lengths are 2.46 Å. Se2- is bonded in a 6-coordinate geometry to six equivalent Co2+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on Rb(CoSe)2 by Materials Project

Rb(CoSe)2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All Rb–Se bond lengths are 3.52 Å. Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.36 Å. Se2- is bonded in a 8-coordinate geometry to four equivalent Rb1+ and four equivalent Co+1.50+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on Cs(CoSe)2 by Materials Project

Cs(CoSe)2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Cs1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All Cs–Se bond lengths are 3.64 Å. Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.36 Å. Se2- is bonded in a 8-coordinate geometry to four equivalent Cs1+ and four equivalent Co+1.50+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on KTl(CoSe)4 by Materials Project

KTl(CoSe)4 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All K–Se bond lengths are 3.41 Å. Co+1.50+ is bonded to four Se2- atoms to form a mixture of edge and corner-sharing CoSe4 tetrahedra. There are two shorter (2.34 Å) and two longer (2.35 Å) Co–Se bond lengths. Tl1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All Tl–Se bond lengths are 3.42 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Co+1.50+ and four equivalent Tl1+ atoms. In the second Se2- site, Se2- is bonded in a 8-coordinate geometry to four equivalent K1+ and four equivalent Co+1.50+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on KTl4(CoSe)10 by Materials Project

KTl4(CoSe)10 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All K–Se bond lengths are 3.40 Å. There are three inequivalent Co+1.50+ sites. In the first Co+1.50+ site, Co+1.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.34 Å. In the second Co+1.50+ site, Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of corner and edge-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.33 Å. In the third Co+1.50+ site, Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of corner and edge-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.33 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are four shorter (3.40 Å) and four longer (3.41 Å) Tl–Se bond lengths. In the second Tl1+ site, Tl1+ is bonded in a body-centered cubic geometry to eight Se2- atoms. All Tl–Se bond lengths are 3.41 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Co+1.50+ and four equivalent Tl1+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Co+1.50+ and four equivalent Tl1+ atoms. In the third Se2- site, Se2- is bonded in a 8-coordinate geometry to four equivalent K1+ and four equivalent Co+1.50+ atoms. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to four equivalent Co+1.50+ and four equivalent Tl1+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on CoSeS by Materials Project

CoSeS is pyrite-derived structured and crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Co4+ is bonded to three equivalent Se2- and three equivalent S2- atoms to form corner-sharing CoSe3S3 octahedra. The corner-sharing octahedral tilt angles are 63°. All Co–Se bond lengths are 2.40 Å. All Co–S bond lengths are 2.31 Å. Se2- is bonded in a 4-coordinate geometry to three equivalent Co4+ and one S2- atom. The Se–S bond length is 2.39 Å. S2- is bonded in a 4-coordinate geometry to three equivalent Co4+ and one Se2- atom.

36 MATERIALS SCIENCE↗

Materials Data on Tl(CoSe)2 by Materials Project

TlCo2Se2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of corner and edge-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.34 Å. Tl1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All Tl–Se bond lengths are 3.44 Å. Se2- is bonded in a 4-coordinate geometry to four equivalent Co+1.50+ and four equivalent Tl1+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on K(CoSe)2 by Materials Project

KCo2Se2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All K–Se bond lengths are 3.41 Å. Co+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CoSe4 tetrahedra. All Co–Se bond lengths are 2.35 Å. Se2- is bonded in a 8-coordinate geometry to four equivalent K1+ and four equivalent Co+1.50+ atoms.

36 MATERIALS SCIENCE↗

Emergence of two distinct phase transitions in monolayer CoSe2 on graphene

Abstract Dimensional modifications play a crucial role in various applications, especially in the context of device miniaturization, giving rise to novel quantum phenomena. The many-body dynamics induced by dimensional modifications, including electron-electron, electron-phonon, electron-magnon and electron-plasmon coupling, are known to significantly affect the atomic and electronic properties of the materials. By reducing the dimensionality of orthorhombic CoSe 2 and forming heterostructure with bilayer graphene using molecular beam epitaxy, we unveil the emergence of two types of phase transitions through angle-resolved photoemission spectroscopy and scanning tunneling microscopy measurements. We disclose that the 2 × 1 superstructure is associated with charge density wave induced by Fermi surface nesting, characterized by a transition temperature of 340 K. Additionally, another phase transition at temperature of 160 K based on temperature dependent gap evolution are observed with renormalized electronic structure induced by electron-boson coupling. These discoveries of the electronic and atomic modifications, influenced by electron-electron and electron-boson interactions, underscore that many-body physics play significant roles in understanding low-dimensional properties of non-van der Waals Co-chalcogenides and related heterostructures. Graphical Abstract

36 MATERIALS SCIENCE↗

A transformer of closely spaced pulsed waveforms

Passive circuit, using diodes, transistors, and magnetic cores, transforms the voltage of repetitive positive or negative pulses. It combines a pulse transformer with switching devices to effect a resonant flux reset and can transform various pulsed waveforms that have a nonzero average value and are relatively cosely spaced in time.

Niedra, J.↗

Optical fibers and components experiment (A0138-7)

Fiber optics permanent damages induced by ionizing radiation after a long exposure in space and after laboratory tests were examined. Irradiation tests performed with radioactive sources (Sr90 - Y90) were validataed, computer coses used for the fluence and dose profile were verified. The performance of fiber optics waveguides in a low altitude orbit, and the origin of transmission losses in the material were dtermined. High sensitivity to ionizing radiations, however, may be a restriction for optic fiber use on satellites. Irradiation tests on these components using neutrons, gamma rays, and X-rays are carried out. Radiation damage on opticao materials, however, is strongly linked to the test conditions.

Bourrieau, J.↗