Investigation of the Physical Properties for Pnnm-CrB4 under High Pressure
The crystal structure and elastic properties of chromium tetraboride(CrB4)were investigated by pseudopotential plane-wave methods within the Perdew-Burke-Ernzerhof(PBE)form of generalized gradient approximation(GGA).The calculated equilibrium structural parameters of Pnnm-CrB4 are in good agreement with the available experimental data and other theoretical results.Moreover,the elastic constants Cij,bulk modulus B,shear modulus G and elastic modulus E under high pressure were calculated,and the toughness and brittleness of Pnnm-CrB4 under high pressure were analyzed with the Poisson ratio σ and B/G.To study the elastic anisotropy of Pnnm-CrB4 in detail,the anisotropic factors A1,A4,A3 for shear and Ba,Bb,Bc for the directional bulk modulus were also calculated.The Vickers hardnessHvof Pnnm-CrB4 was estimated at the same time.Finally,the total and partial density of states of Pnnm-CrB4 under high pressure were studied so as to have a better understanding of the mechanical and elastic properties of Pnnm-CrB4.
Pnnm-CrB4density functional theoryhigh pressureelasticity modulusductile and brittleelastic anisotropyhardnessdensity of state
国家科技期刊平台
NSTL
万方数据
