Academic Journal

Structural, vibrational, and electronic behavior of two GaGeTe polytypes under compression

التفاصيل البيبلوغرافية
العنوان: Structural, vibrational, and electronic behavior of two GaGeTe polytypes under compression
المؤلفون: E. Bandiello, S. Gallego-Parra, A. Liang, J.A. Sans, V. Cuenca-Gotor, E. Lora da Silva, R. Vilaplana, P. Rodríguez-Hernández, A. Muñoz, D. Diaz-Anichtchenko, C. Popescu, F.G. Alabarse, C. Rudamas, C. Drasar, A. Segura, D. Errandonea, F.J. Manjón
المصدر: Materials Today Advances, Vol 19, Iss , Pp 100403- (2023)
بيانات النشر: Elsevier, 2023.
سنة النشر: 2023
المجموعة: LCC:Materials of engineering and construction. Mechanics of materials
مصطلحات موضوعية: Materials of engineering and construction. Mechanics of materials, TA401-492
الوصف: GaGeTe is a layered topological semimetal that has been recently found to exist in at least two different polytypes, α-GaGeTe (R3¯m) and β-GaGeTe (P63mc). Here we report a joint experimental and theoretical study of the structural, vibrational, and electronic properties of these two polytypes in high-pressure conditions. Both polytypes show anisotropic compressibility and two phase transitions, above 7 and 15 GPa, respectively, as confirmed by XRD and Raman spectroscopy measurements. Although the nature of the high-pressure phases could not be confirmed, comparison with other chalcogenides and total-energy calculations allow us to propose possible high-pressure phases for both polytypes with an increase in coordination for Ga and Ge atoms from 4 to 6. In particular, the simplification of the X-ray pattern for both polytypes above 15 GPa suggests a transition to a structure of relatively higher symmetry than the original one. This result is consistent with the rocksalt-like high-pressure phases observed in parent III-VI semiconductors, such as GaTe, GaSe, and InSe. Pressure-induced amorphization is observed upon pressure release. The electronic band structures of α-GaGeTe and β-GaGeTe and their pressure dependence also show similarities to III-VI semiconductors, thus suggesting that the germanene-like sublayer induces a semimetallic character in both GaGeTe polytypes. Above 3 GPa, both polytypes lose their topological features, due to the opening of the direct band gap, while the reduction of the interlayer space increases the thermal conductivity at high pressure.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 2590-0498
Relation: http://www.sciencedirect.com/science/article/pii/S2590049823000632; https://doaj.org/toc/2590-0498
DOI: 10.1016/j.mtadv.2023.100403
URL الوصول: https://doaj.org/article/f727a5bd6cad4ebfb180f3d1bc2e2525
رقم الانضمام: edsdoj.f727a5bd6cad4ebfb180f3d1bc2e2525
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:25900498
DOI:10.1016/j.mtadv.2023.100403