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DOE OSTI · 1310005

Materials Data on GeTe7As4 by Materials Project

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Abstract

As2Te3(GeTe)As2Te3 is MAX Phase-like structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one As2Te3 sheet oriented in the (0, 0, 1) direction and one As2Te3(GeTe) sheet oriented in the (0, 0, 1) direction. In the As2Te3 sheet, As1+ is bonded to six Te+1.14- atoms to form a mixture of edge and corner-sharing AsTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.86 Å) and three longer (3.01 Å) As–Te bond lengths. There are two inequivalent Te+1.14- sites. In the first Te+1.14- site, Te+1.14- is bonded in a 3-coordinate geometry to three equivalent As1+ atoms. In the second Te+1.14- site, Te+1.14- is bonded to six equivalent As1+ atoms to form edge-sharing TeAs6 octahedra. In the As2Te3(GeTe) sheet, Ge4+ is bonded to six equivalent Te+1.14- atoms to form GeTe6 octahedra that share corners with six equivalent AsTe6 octahedra, edges with six equivalent GeTe6 octahedra, and edges with six equivalent AsTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Ge–Te bond lengths are 2.97 Å. As1+ is bonded to six Te+1.14- atoms to form AsTe6 octahedra that share corners with three equivalent GeTe6 octahedra, edges with three equivalent GeTe6 octahedra, and edges with six equivalent AsTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (2.85 Å) and three longer (3.03 Å) As–Te bond lengths. There are two inequivalent Te+1.14- sites. In the first Te+1.14- site, Te+1.14- is bonded in a 3-coordinate geometry to three equivalent As1+ atoms. In the second Te+1.14- site, Te+1.14- is bonded to three equivalent Ge4+ and three equivalent As1+ atoms to form a mixture of edge and corner-sharing TeGe3As3 octahedra. The corner-sharing octahedral tilt angles are 0°.

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36 MATERIALS SCIENCEAs-Ge-Tecrystal structureGeTe7As4

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2020-07-14. Materials Data on GeTe7As4 by Materials Project. https://doi.org/10.17188/1310005

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