A comparative study of the structural, electronic, vibrational, dielectric and elastic properties of the two phases CaAgBi through first-principles calculations

The Structural, Mechanical, Lattice Dynamical, and Thermal Properties of 3D Dirac Semimetals BaXBi (X=Cu, Ag, Au) from First‐Principles Calculations

“…They have fourfold degeneracy points in the k space, where valance and conduction bands touch each other, and the bands near those critical points show a linear energy band dispersion behavior in all directions, which makes them unique. [ 5–9 ] The studies in the literature have theoretically proved that their fourfold degeneracy points are protected by C 3 (A 3 Bi (A = Na, K, Rb), YAuTe (Y = Na, K, Rb), BaXBi (X = Cu, Ag, Au), CaAgBi), or C 4 (Cd 3 As 2 , Ca 3 XO (X = Pb, Sn)) rotation symmetry. [ 5–13 ] Furthermore, 3DSM can be driven into a topological insulator or Weyl semimetal by increasing spin–orbit coupling or breaking symmetry, respectively.…”

“…194) could be important for two known hexagonal structures for topological semimetals. [ 8 ] Also, Chang et al indicate that topological features of BaAgBi, whose point group is P63/mmc (no. 194), will be very useful for future experimental research.…”

“…[ 15 ] Moreover, it has been theoretically revealed that they are 3DSM. [ 5–9 ] Therefore, we need to understand the fundamental properties of the compounds for feasible applications in the future. Due to the lack of the knowledge in the literature and need for current material science, it is a significant task to investigate the structural, mechanical, dynamical, and thermal properties of these materials in detail.…”

“…[1] As far as we know, Weyl semimetal, 3D Dirac semimetal (3DSM), and node-line semimetal are described as topological semimetals. [2][3][4][5][6][7][8] Thanks to their unique electronic properties, 3DSM, sometimes named as "3D graphenes," deserve the interest they attract. They have fourfold degeneracy points in the k space, where valance and conduction bands touch each other, and the bands near those critical points show a linear energy band dispersion behavior in all directions, which makes them unique.…”

“…[5][6][7][8][9] The studies in the literature have theoretically proved that their fourfold degeneracy points are protected by C 3 (A 3 Bi (A ¼ Na, K, Rb), YAuTe (Y ¼ Na, K, Rb), BaXBi (X ¼ Cu, Ag, Au), CaAgBi), or C 4 (Cd 3 As 2 , Ca 3 XO (X ¼ Pb, Sn)) rotation symmetry. [5][6][7][8][9][10][11][12][13] Furthermore, 3DSM can be driven into a topological insulator or Weyl semimetal by increasing spin-orbit coupling or breaking symmetry, respectively. [14] In spite of the importance of 3DSM, they have not received adequate attention.…”