Metal-insulator transition and doping-induced phase change in Ge 2 Sb 2 Se 5 x Te 5 − 5 x
| العنوان: | Metal-insulator transition and doping-induced phase change in Ge 2 Sb 2 Se 5 x Te 5 − 5 x |
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| المؤلفون: | John A. Schneeloch, Zhenyang Xu, Keeseong Park, Despina Louca |
| المصدر: | Applied Physics Letters. 117:193503 |
| بيانات النشر: | AIP Publishing, 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | 010302 applied physics, Materials science, Physics and Astronomy (miscellaneous), Doping, Hexagonal phase, Analytical chemistry, 02 engineering and technology, Activation energy, 021001 nanoscience & nanotechnology, 01 natural sciences, Amorphous solid, Electrical resistivity and conductivity, Phase (matter), 0103 physical sciences, Metal–insulator transition, 0210 nano-technology, Ground state |
| الوصف: | Ge2Sb2Te5 (GST-225), a phase change material (PCM) with vast differences in the electrical and optical characteristics between its amorphous and crystalline phases, is revisited to explore its properties with Se doping. GST crystallizes in a layered hexagonal ground state, while the precursor to the amorphous state is a distorted rock salt like structure with vacancies at the Ge/Sb sites. Upon doping, liquid nitrogen quenched Ge 2 Sb 2 Se 5 x Te 5 − 5 x (GSST-225) exhibits a direct hexagonal-to-amorphous phase change above x > 0.8, whereas the rock salt like structure appears as a second phase with a volume fraction that does not change as a function of the doping. The phase change is accompanied by a metal-to-insulator transition (MIT), with a several orders of magnitude increase in the resistivity on approaching the amorphous state. A similar MIT is observed even without the phase change in hexagonal crystals with doping levels above x > 0.8. On warming amorphous GSST (x = 0.9) above room temperature, a reversal to the hexagonal phase occurs with a re-crystallization onset temperature (Tc) above 300 °C, much higher than the Tc (∼ 170 °C) of amorphous GST and an activation energy of 1.47 eV, which is comparable to good glass formers. |
| تدمد: | 1077-3118 0003-6951 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::dd1e27f02e3571ed757fe7e40cc9ec54 https://doi.org/10.1063/5.0030956 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........dd1e27f02e3571ed757fe7e40cc9ec54 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Scitation. | تدمد: | 10773118 00036951 |
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