Ge$_{136}$ type-II clathrate as precursor for the synthesis of metastable germanium polymorphs: a computational study

التفاصيل البيبلوغرافية
العنوان: Ge$_{136}$ type-II clathrate as precursor for the synthesis of metastable germanium polymorphs: a computational study
المؤلفون: Selli, Daniele, Baburin, Igor A., Martoňák, Roman, Leoni, Stefano
سنة النشر: 2022
المجموعة: Condensed Matter
Physics (Other)
مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Other Condensed Matter, Physics - Computational Physics
الوصف: The response to compression of the clathrate type-II structure Ge(cF136) is investigated by means of \textit{ab initio} small-cell metadynamics at different temperatures and pressures. At lower pressure $p$=2.5 GPa the metastable metallic bct-5 phase competes against $\beta$-Sn Ge(tI4), which forms at higher pressures. On lowering temperature, the presence of amorphous intermediates obtained from Ge$_{136}$ is more pronounced and is instrumental to the formation of denser structural motifs, from which metallic bct-5 can form. Therein, anisotropic box fluctuations promote phase formation. The metadynamics runs are analysed in depth using a set of topological descriptors, including coordination sequence and ring statistics. Differences in the structural landscape history and amorphous intermediates are critical for the selective formation of particular metastable polymorphs, towards turning crystal structure predictions into actual materials.
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.106.174102
URL الوصول: http://arxiv.org/abs/2208.06282
رقم الأكسشن: edsarx.2208.06282
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.106.174102