Structural, electronic, mechanical and thermodynamic properties of Cr–Si binary silicides from first-principles investigations

Influence of high pressure on the structure, hardness and brittle-to-ductile transition of NbSi2 ceramics

Sulfur vacancy enhances the electronic and optical properties of FeS2 as the high performance electrode material

First-principles prediction of structure and mechanical properties of TM5SiC2 ternary silicides

The influence of vacancy defects on elastic and electronic properties of TaSi (5/3) desilicides from a first-principles calculations

The anisotropy in elasticity, mechanical properties and electronic properties of CaM2Al20 (M = V, Nb, Cr, Ti, Mo and Ta) compounds were investigated using the first-principle calculations. These ternary compounds are structurally stable according to the obtained phonon frequencies and formation enthalpy. The results of elastic modulus, hardness and elastic constants explain that CaM2Al20 intermetallics have higher hardness and better resistance to deformation change than pure aluminum. Poisson’s ratio and the values of B/G confirm that CaTi2Al20, CaV2Al20, CaCr2Al20, CaNb2Al20 and CaTa2Al20 are brittle materials, but CaMo2Al20 is ductile material. The 3D surfaces of Young’s modulus and anisotropic constants confirm that CaMo2Al20 and CaTi2Al20 have the larger anisotropy than other four compounds. What’s more, the density of states and charge density differences of CaM2Al20 compounds explain the mechanism of the structural stability and mechanical properties.

A first principles investigation on the influence of transition-metal elements on the structural, mechanical, and anisotropic properties of CaM2Al20 intermetallics.

As so far, the development and application prospects of transition metal silicon-based materials have received the considerable attention. V-Si silicides are one of the most important silicon-based high-temperature materials. Brittle behavior hinders their wide application. In present work, the influence of vackancies on mechanical properties, brittle/ductile behavior and electronic properties of V5Si3 silicides is studied using the first-principles calculations. The vacancy formation energy, elastic constants, elastic modulus, brittle/ductile behavior and electronic behavior of the perfect V5Si3 and V5Si3 with vacancies were comparatively calculated and discussed, respectively. The thermodynamic data and phonon frequencies demonstrate that the V5Si3 with different vacancies can exhibit the structural stability. Although the vacancies weaken the hardness of V5Si3, the vacancies improve the brittle behavior of the parent V5Si3. Especially, the Si-Va1 and Si-Va2 vacancies in V5Si3 induced brittle-to-ductile transition for V5Si3 desilicides. The electronic structures explain the mechanism of the difference of mechanical properties for different vacancies.

Tianhui Dong

Papers

A first principles investigation on the influence of transition-metal elements on the structural, mechanical, and anisotropic properties of CaM2Al20 intermetallics.

Insight into the vacancy effects on mechanical and electronic properties of V5Si3 silicides from first-principles calculations.

Investigation of the structural stability, mechanical, and thermodynamic properties of Hf5BSi3 silicide with vacancies defects