(GeTe){sub n}SbInTe{sub 3} (n≤3)—Element distribution and thermal behavior
- Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany)
- Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany)
Antimony in germanium antimony tellurides (GeTe){sub n}(Sb{sub 2}Te{sub 3}) can be substituted by indium. Homogeneous bulk samples of GeSbInTe{sub 4} (R3-bar m, Z=3, a=4.21324(5) Å, c=41.0348(10) Å) and Ge{sub 2}SbInTe{sub 5} (P3-bar m1, Z=1, a=4.20204(6) Å, c=17.2076(4) Å) were obtained; their structures were refined with the Rietveld method. Single-crystal X-ray diffraction using synchrotron radiation at the K edges of Sb and Te (exploiting anomalous dispersion) yields precise information on the element distribution in the trigonal layered structure of Ge{sub 3}SbInTe{sub 6} (R3-bar m, Z=3, a=4.19789(4) Å, c=62.1620(11) Å). The structure is characterized by van der Waals gaps between distorted rocksalt-type slabs of alternating cation and anion layers. The cation concentration is commensurately modulated with Sb preferring the positions near the gaps. In contrast to unsubstituted Ge{sub 3}Sb{sub 2}Te{sub 6}, quenching the NaCl-type high-temperature phase (stable above ∼510 °C) easily yields a pseudocubic modification that is metastable at ambient conditions. Temperature-dependent powder diffraction reveals a broader stability range of the cubic high-temperature modification of Ge{sub 3}SbInTe{sub 6} compared to the ternary phases. In-containing samples partially decompose at ca. 300 °C but become homogeneous again when the high-temperature phase is formed. - Graphical abstract: Crystal structure of 33R-Ge{sub 3}SbInTe{sub 6} as determined by resonant X-ray diffraction, one example of the (GeTe){sub n}SbInTe{sub 3} series of compounds investigated. - Highlights: • The new compounds 21R-GeSbInTe{sub 4}, 9P-Ge{sub 2}SbInTe{sub 5} and 33R-Ge{sub 3}SbInTe are described. • The element distribution in 33R-Ge{sub 3}SbInTe{sub 6} was determined by resonant scattering. • The cation concentration in the crystal structure is strongly modulated. • The Sb substitution by In has a significant impact on phase transitions. • Results may be relevant for thermoelectrics and thin-film phase-change materials.
- OSTI ID:
- 22309061
- Journal Information:
- Journal of Solid State Chemistry, Vol. 208; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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