First‐principles study on stability, Debye temperature, mechanical, electronic and magnetic properties of Fe₂B compounds

Abstract

In this work, the stability, Debye temperature, mechanical, electronic and magnetic properties of four kinds of Fe2B with the different crystal structures were investigated by first‐principles calculation, and the results of Fe2B with or without spin polarization were comparatively analyzed. It was found that spin polarization increases the thermodynamic stability and Debye temperature of T1 (ICSD NO: 30446) and T2 (42530), but reduces that of T3 (16809) and T4 (160789). Only T1 and T2 are thermodynamically stable compounds, but all of the Fe2B are mechanically stable. Ferromagnetic T1 and T2 have the largest Young's modulus, shear modulus, Vickers hardness and fracture toughness. Moreover, their Vickers hardness is much larger than that of the others. Electronic structures revealed that the larger modulus (B, E and G) of T1 and T2 originate from their stronger Fe‐Fe bonds and/or weaker elastic anisotropy. The Ms of unit cell of T3 and T4 are larger than that of T1 and T2. Thus, ferromagnetic T1 and T2 can be considered as the excellent candidates for high‐performance wear‐resistance materials and strong ferromagnetic materials with high hardness, whereas the T3 and T4 are just suitable for the application of strong ferromagnetic materials without wear.

Exploring the structural, mechanical and thermodynamic properties of Ti‐V solid solutions

“…According to the structural symmetry, the B and G of two Ti‐V solid solutions are calculated by the Voigt–Reuss–Hill (VRH) approximation [50]. In addition, the brittle‐or‐ductile behavior is an important index for checking the plastic working for these high‐temperature materials [51, 52]. According to Pugh rule ( B / G = 1.75) [53], If B / G ≥ 1.75, the solid shows the ductility.…”

“…approximation [50]. In addition, the brittle-or-ductile behavior is an important index for checking the plastic working for these high-temperature materials [51,52]. According to Pugh rule (B/G = 1.75) [53], If B/G ≥ 1.75, the solid shows the ductility.…”