Mechanical Properties, Electronic Structures, and Debye Temperature of NixBy Compounds Obtained by the First Principles Calculations

Abstract

Mechanical properties, electronic properties, and Debye temperatures of Ni x B y (Ni 3 B, Ni 2 B, Ni 4 B 3 and NiB) compounds were obtained by the first principles calculations based on the density functional theory (DFT). The results showed that the formation enthalpy of the Ni x B y compounds were stable with negative formation enthalpy. NiB had the largest B, G, and E, and the smallest υ; it also had the highest hardness (10.8 GPa) and Debye temperature (681.8 K). Ni 4 B 3 had the strongest anisotropy. It was found that the valence bonds of the Ni x B y compounds studied were composed of both metal bond and covalent bond, and the mechanical properties and Debye temperature of the Ni x B y compounds increased with the increase of the B atomic ratio.

Synthesis of Ni–B Compounds by High-Pressure and High-Temperature Method

“…Figure and Table S1 indicate that Ni 2 B, α-Ni 4 B 3 , β-Ni 4 B 3 , and NiB have negative E coh and Δ H r . It is consistent with the previous results of formation energy which demonstrate that all of these structures are stable . Moreover, α-Ni 4 B 3 is the most stable phase, followed by β-Ni 4 B 3 , Ni 2 B, and NiB.…”

“…Thus, the Ni 3 B is not considered in this work. The skeletons of structures for Ni 2 B ( I 4 /mcm ), α-Ni 4 B 3 ( Pnma ), β-Ni 4 B 3 ( C 2 /c ), and NiB ( Cmcm ) are shown in Figure . Ni atoms can form a three-dimensional (3D) skeleton in Ni 2 B, due to the high Ni content (Figure a).…”

“…The first principle calculations of Ni x B y compounds (B ( R 3̅ m ), Ni ( Fm 3̅ m ), Ni 2 B ( I 4/ mcm ), α - Ni 4 B 3 ( Pnma ), β- Ni 4 B 3 ( C 2/ c ), and NiB ( Cmcm )) were executed with the Cambridge Serial Total Energy Package (CASTEP) program using density functional theory (DFT). The DFT exchange-correlation contribution is calculated using the Generalized-Gradient-Approximation (GGA) through the Perdew–Burke–Ernzerhof (PBE) functional.…”

Microstructure and mechanical properties of Ni matrix B4C reinforced functionally graded composites

“…In summary, when the hardness of the samples in the table was examined, it was found that the hardness of the outer layers of the samples subjected to heat treatment at 900 ℃ and 1050 ℃ increased as the sintering time and B 4 C rate increased. In their studies, Wang et al, stated that Ni 4 B 3 phase had the strongest anisotropy and while the hardness value was 8.3 GPa for Ni 3 B phase, it was around 9.7 GPa for 8 Ni 4 B 3 phase [18]. Due to different hard phases (such as Ni 4 B 3 ) formed, the highest hardness increase was obtained from the samples sintered at 1050 ℃.…”

From binary to ternary and back to binary: Transition of electromagnetic wave shielding to absorption among MAB phase Ni 3ZnB 2 and corresponding binary borides Ni n+1 B n ( n = 1, 3)

“…Various crystal structures of these substrates contribute to their varied properties and applications in various fields. Nevertheless, nickelboron compounds, being promising functional materials, exhibit a range of appealing characteristics, including high hardness, high melting point, remarkable thermal stability, excellent catalytic, and satisfactory electronic properties [25][26][27].…”