Thermal stability of amorphous metal chalcogenide thin films
| Autor: | I. Stavarache, Florinel Sava, I.D. Simandan, Alin Velea, C. Mihai, Corneliu Porosnicu |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Amorphous metal Materials science Chalcogenide 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Amorphous solid law.invention chemistry.chemical_compound Chemical engineering chemistry law Phase (matter) 0103 physical sciences Materials Chemistry Ceramics and Composites Thermal stability Crystallite Thin film Crystallization 0210 nano-technology |
| Zdroj: | Journal of Non-Crystalline Solids. 559:120663 |
| ISSN: | 0022-3093 |
| Popis: | Amorphous metal chalcogenides have good switching properties for resistive memories, but have low thermal stability. In this work, the response to rapid thermal stress, as high as 550 °C, of amorphous Cu-GeSe, Ag-GeSe, Cu-GeTe, Ag-GeTe thin films, is investigated. Metal-GeTe films, which are amorphous up to 280 °C, are the most stable. Metal-GeSe films start to crystallize at 190 °C and a Cu1.59Se phase, with 20.5% Cu vacancies and a structure similar to the c-Cu2-xSe superionic conductor, is formed. This might boost the performance of memory devices. Silver atoms migration is facilitated in Ag-GeSe by poor crystallization (below 5%, at all temperatures). Difussion of Ag is enhanced in Ag-GeTe, due to the crystallization of the cubic (Ag2Te)4-GeTe2 (Ag8GeTe6) phase, which has Ag+ vacancies. In Cu-GeTe, the formation of stoichiometric polycrystalline Cu0.67Ge0.33Te might hinder diffusion. An unusual anisotropic behaviour (increase in thickness, simultaneously with contraction of surface) is observed at 100 °C in Cu-GeSe and Cu-GeTe thin films, which suggests the orientation of the amorphous clusters package along a preferential direction. |
| Databáze: | OpenAIRE |
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