Topological Dirac Semimetal Phase in Bismuth Based Anode Materials for Sodium-Ion Batteries

Condensed Matter

Amit Agarwal¹  Sougata Mardanya¹  Arun Bansil²  Wei-Chi Chiu²  Bernardo Barbiellini²  Bahadur Singh²  Johannes Nokelainen³  Katariina Pussi³  Hsin Lin⁴  Christopher Lane⁵ 

[1] Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India;Department of Physics, Northeastern University, Boston, MA 02115, USA;Department of Physics, School of Engineering Science, LUT University, FI-53851 Lappeenranta, Finland;Institute of Physics, Academia Sinica, Taipei 11529, Taiwan;Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA;

关键词: sodium-ion battery;    topological Dirac semimetal;    Na3Bi;    density functional theory;   

DOI  :  10.3390/condmat5020039

来源: DOAJ

【 摘 要 】

Bismuth has recently attracted interest in connection with Na-ion battery anodes due to its high volumetric capacity. It reacts with Na to form Na ${}_3$ Bi which is a prototypical Dirac semimetal with a nontrivial electronic structure. Density-functional-theory based first-principles calculations are playing a key role in understanding the fascinating electronic structure of Na ${}_3$ Bi and other topological materials. In particular, the strongly-constrained-and-appropriately-normed (SCAN) meta-generalized-gradient-approximation (meta-GGA) has shown significant improvement over the widely used generalized-gradient-approximation (GGA) scheme in capturing energetic, structural, and electronic properties of many classes of materials. Here, we discuss the electronic structure of Na ${}_3$ Bi within the SCAN framework and show that the resulting Fermi velocities and s-band shift around the $\Gamma$ point are in better agreement with experiments than the corresponding GGA predictions. SCAN yields a purely spin-orbit-coupling (SOC) driven Dirac semimetal state in Na ${}_3$ Bi in contrast with the earlier GGA results. Our analysis reveals the presence of a topological phase transition from the Dirac semimetal to a trivial band insulator phase in Na ${}_3$ Bi ${}_x$ Sb ${}_{1-x}$ alloys as the strength of the SOC varies with Sb content, and gives insight into the role of the SOC in modulating conduction properties of Na ${}_3$ Bi.

【 授权许可】

Unknown