The structural,electronic and elastic properties of the M_2SiC phases were studied,where M are 3d,4d,and 5d early transition metals.The valence electron concentration(VEC) effect of Ti,V,Cr,Zr,Nb,Mo,Hf,Ta and W on the...The structural,electronic and elastic properties of the M_2SiC phases were studied,where M are 3d,4d,and 5d early transition metals.The valence electron concentration(VEC) effect of Ti,V,Cr,Zr,Nb,Mo,Hf,Ta and W on these properties was examined.The C_(44) saturates for a VEC value in surrounding of 8.5 for each serie.Hf-s,Ta-s and W-s electrons mainly contribute to the density of states at the Fermi level,and should be involved in the conduction properties.The distortion increases with increasing VEC and decreasing k_c/k_a factor except for the series M=Ti,V and Cr,where it is lower at the VEC value of 8.5(it follows a parabolic variation).The M_2SiC was characterized by a profound anisotropy for the shear planes(1010) and compressibility in the direction is higher than that along the cone except for W_2SiC,where it is lower.展开更多
文摘The structural,electronic and elastic properties of the M_2SiC phases were studied,where M are 3d,4d,and 5d early transition metals.The valence electron concentration(VEC) effect of Ti,V,Cr,Zr,Nb,Mo,Hf,Ta and W on these properties was examined.The C_(44) saturates for a VEC value in surrounding of 8.5 for each serie.Hf-s,Ta-s and W-s electrons mainly contribute to the density of states at the Fermi level,and should be involved in the conduction properties.The distortion increases with increasing VEC and decreasing k_c/k_a factor except for the series M=Ti,V and Cr,where it is lower at the VEC value of 8.5(it follows a parabolic variation).The M_2SiC was characterized by a profound anisotropy for the shear planes(1010) and compressibility in the direction is higher than that along the cone except for W_2SiC,where it is lower.
