Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 59: Electronic Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond - VI

MM 59.12: Vortrag

Donnerstag, 23. März 2017, 13:15–13:30, GER 38

Structure, nonstoichiometry, and geometrical frustration of α-tetragonal boron — •Jens Kunstmann¹, Naoki Uemura², Hagen Eckert¹, and Koun Shirai² — ¹TU Dresden, Germany — ²Osaka University, Japan

It is currently believed that boron in the α-tetragonal structure is not an elemental crystal. Here we contradict this view and resolve the structural and thermodynamic characteristics of pure α-tetragonal boron via density functional theory calculations. The conditions for stable covalent bonding are almost fulfilled at a stoichiometric composition B₅₂. This phase is an elemental crystals with geometrical frustration. Furthermore, our thermodynamic considerations show that small, positive deviations from the stoichiometric composition occur at finite temperatures. [Uemura, Shirai, Eckert, Kunstmann, Phys. Rev. B 93, 104101 (2016)]