Enrichment of GeSbTe alloys with germanium has been proposed as a valid approach to increase the crystallization temperature and therefore to address high-temperature applications of non-volatile phase change memories, such as embedded or automotive applications. However, the tendency of Ge-rich GeSbTe alloys to decompose with the segregation of pure Ge still calls for investigations on the basic mechanisms leading to element diffusion and compositional vari-ations. With the purpose of identifying some possible routes to limit the Ge segregation, in this study, we investigate Ge-rich Sb2 Te3 and Ge-rich Ge2 Sb2 Te5 with low (<40 at %) or high (>40 at %) amounts of Ge. The formation of the crystalline phases has been followed as a function of annealing temperature by X-ray diffraction. The temperature dependence of electrical properties has been evaluated by in situ resistance measurements upon annealing up to 300◦ C. The segregation and decomposition processes have been studied by scanning transmission electron microscopy (STEM) and discussed on the basis of density functional theory calculations. Among the studied compositions, Ge-rich Ge2 Sb2 Te5 is found to be less prone to decompose with Ge segregation.

Cecchi, S., Garcia, I., Mio, A., Zallo, E., Kheir, O., Calarco, R., et al. (2022). Crystallization and Electrical Properties of Ge-Rich GeSbTe Alloys. NANOMATERIALS, 12(4) [10.3390/nano12040631].

Crystallization and Electrical Properties of Ge-Rich GeSbTe Alloys

Cecchi S.
Primo
;
Kheir O. A. E.;Bernasconi M.;
2022

Abstract

Enrichment of GeSbTe alloys with germanium has been proposed as a valid approach to increase the crystallization temperature and therefore to address high-temperature applications of non-volatile phase change memories, such as embedded or automotive applications. However, the tendency of Ge-rich GeSbTe alloys to decompose with the segregation of pure Ge still calls for investigations on the basic mechanisms leading to element diffusion and compositional vari-ations. With the purpose of identifying some possible routes to limit the Ge segregation, in this study, we investigate Ge-rich Sb2 Te3 and Ge-rich Ge2 Sb2 Te5 with low (<40 at %) or high (>40 at %) amounts of Ge. The formation of the crystalline phases has been followed as a function of annealing temperature by X-ray diffraction. The temperature dependence of electrical properties has been evaluated by in situ resistance measurements upon annealing up to 300◦ C. The segregation and decomposition processes have been studied by scanning transmission electron microscopy (STEM) and discussed on the basis of density functional theory calculations. Among the studied compositions, Ge-rich Ge2 Sb2 Te5 is found to be less prone to decompose with Ge segregation.
Articolo in rivista - Articolo scientifico
Crystallization temperature; Electrical properties; Ge-rich alloys; Segregation;
English
Cecchi, S., Garcia, I., Mio, A., Zallo, E., Kheir, O., Calarco, R., et al. (2022). Crystallization and Electrical Properties of Ge-Rich GeSbTe Alloys. NANOMATERIALS, 12(4) [10.3390/nano12040631].
Cecchi, S; Garcia, I; Mio, A; Zallo, E; Kheir, O; Calarco, R; Bernasconi, M; Nicotra, G; Privitera, S
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/356322
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