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9 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Structure and disorder resulting in ultralow thermal conductivity in the defect chalcopyrite AgInSnSe 4

Quaternary chalcogenides are attractive for a variety of technological fields of interest due to the diverse physical properties these materials possess. Herein, the structural and thermal properties of the disordered chalcopyrite AgInSnSe 4 are reported revealing a distinct relation between its structure and physical properties. Modeling of the experimental temperature-dependent thermal properties revealed an ultralow thermal conductivity (0.47 Wm -1 K -1 at room temperature) due to lattice anharmonicity, a low speed of sound and a low Debye temperature. Moreover, first principles electronic structure calculations revealed that the Ag-Se tetrahedra within the crystal structure possess relatively weak bonds due to occupied antibonding states from p-d orbital hybridization, which suppress the thermal conductivity. Here, in order to further quantify our findings, we extended our analyses to include comparisons with other ternary and quaternary adamantine materials, all of which possess a fourfold tetrahedral coordination of atoms, in revealing the origin of the thermal properties in AgInSnSe 4 .

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag2Se by Materials Project

Ag2Se crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Ag1+ is bonded in a 4-coordinate geometry to four equivalent Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.74–2.89 Å. Se2- is bonded to eight equivalent Ag1+ atoms to form a mixture of corner and edge-sharing SeAg8 hexagonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgSe by Materials Project

AgSe is Zincblende, Sphalerite structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ag2+ is bonded to four equivalent Se2- atoms to form corner-sharing AgSe4 tetrahedra. All Ag–Se bond lengths are 2.59 Å. Se2- is bonded to four equivalent Ag2+ atoms to form corner-sharing SeAg4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag2Se by Materials Project

Ag2Se crystallizes in the orthorhombic P222_1 space group. The structure is three-dimensional. there are three inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to four Ag1+ and three equivalent Se2- atoms. There are a spread of Ag–Ag bond distances ranging from 2.70–2.90 Å. There are a spread of Ag–Se bond distances ranging from 2.63–2.92 Å. In the second Ag1+ site, Ag1+ is bonded in a 10-coordinate geometry to four Ag1+ and six equivalent Se2- atoms. Both Ag–Ag bond lengths are 2.80 Å. There are four shorter (3.05 Å) and two longer (3.18 Å) Ag–Se bond lengths. In the third Ag1+ site, Ag1+ is bonded in a 10-coordinate geometry to four Ag1+ and six equivalent Se2- atoms. Both Ag–Ag bond lengths are 2.85 Å. There are a spread of Ag–Se bond distances ranging from 3.03–3.17 Å. Se2- is bonded in a 9-coordinate geometry to nine Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag2Se by Materials Project

Ag2Se is Cotunnite structured and crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to three equivalent Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.67–2.79 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four equivalent Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.73–2.96 Å. Se2- is bonded in a 7-coordinate geometry to seven Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag2Se by Materials Project

Ag2Se crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent Se2- atoms. There are one shorter (2.56 Å) and one longer (2.58 Å) Ag–Se bond lengths. In the second Ag1+ site, Ag1+ is bonded in a 3-coordinate geometry to three equivalent Se2- atoms. There are two shorter (2.64 Å) and one longer (2.87 Å) Ag–Se bond lengths. Se2- is bonded in a 5-coordinate geometry to five Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag2Se by Materials Project

Ag2Se crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to three equivalent Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.68–3.07 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four equivalent Se2- atoms. There are a spread of Ag–Se bond distances ranging from 2.62–3.12 Å. Se2- is bonded in a 7-coordinate geometry to seven Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag3Se by Materials Project

Ag3Se is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ag sites. In the first Ag site, Ag is bonded to eight Ag and four equivalent Se atoms to form distorted AgAg8Se4 cuboctahedra that share corners with four equivalent SeAg12 cuboctahedra, corners with fourteen AgAg8Se4 cuboctahedra, edges with six equivalent SeAg12 cuboctahedra, edges with twelve AgAg8Se4 cuboctahedra, faces with four equivalent SeAg12 cuboctahedra, and faces with sixteen AgAg8Se4 cuboctahedra. There are a spread of Ag–Ag bond distances ranging from 2.94–3.09 Å. All Ag–Se bond lengths are 3.01 Å. In the second Ag site, Ag is bonded to eight Ag and four equivalent Se atoms to form distorted AgAg8Se4 cuboctahedra that share corners with four equivalent SeAg12 cuboctahedra, corners with fourteen AgAg8Se4 cuboctahedra, edges with six equivalent SeAg12 cuboctahedra, edges with twelve AgAg8Se4 cuboctahedra, faces with four equivalent SeAg12 cuboctahedra, and faces with sixteen AgAg8Se4 cuboctahedra. All Ag–Ag bond lengths are 2.96 Å. All Ag–Se bond lengths are 3.01 Å. Se is bonded to twelve Ag atoms to form SeAg12 cuboctahedra that share corners with six equivalent SeAg12 cuboctahedra, corners with twelve AgAg8Se4 cuboctahedra, edges with eighteen AgAg8Se4 cuboctahedra, faces with eight equivalent SeAg12 cuboctahedra, and faces with twelve AgAg8Se4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgSe5 by Materials Project

AgSe5 crystallizes in the monoclinic Cc space group. The structure is one-dimensional and consists of two AgSe5 ribbons oriented in the (0, 0, 1) direction. Ag2+ is bonded to four Se+0.40- atoms to form distorted corner-sharing AgSe4 tetrahedra. There are a spread of Ag–Se bond distances ranging from 2.56–2.89 Å. There are five inequivalent Se+0.40- sites. In the first Se+0.40- site, Se+0.40- is bonded in a distorted L-shaped geometry to two equivalent Ag2+ and one Se+0.40- atom. The Se–Se bond length is 2.36 Å. In the second Se+0.40- site, Se+0.40- is bonded in a distorted water-like geometry to two Se+0.40- atoms. The Se–Se bond length is 2.33 Å. In the third Se+0.40- site, Se+0.40- is bonded in a distorted water-like geometry to two Se+0.40- atoms. The Se–Se bond length is 2.42 Å. In the fourth Se+0.40- site, Se+0.40- is bonded in a 1-coordinate geometry to one Ag2+ and two Se+0.40- atoms. The Se–Se bond length is 2.33 Å. In the fifth Se+0.40- site, Se+0.40- is bonded in a distorted single-bond geometry to one Ag2+ and one Se+0.40- atom.

36 MATERIALS SCIENCE↗