Electronic structure and chemical bond of Ti₃SiC₂ and adding Al element

Abstract

The relation among electronic structure, chemical bond and property of Ti₃SiC₂ and Al-doped was studied by density function and discrete variation (DFT-DVM) method. When Al element is added into Ti₃SiC₂, there is a less difference of ionic bond, which does not play a leading role to influent the properties. After adding Al, the covalent bond of Al and the near Ti becomes somewhat weaker, but the covalent bond of Al and the Si in the same layer is obviously stronger than that of Si and Si before adding. Therefore, in preparation of Ti₃SiC₂, adding a proper quantity of Al can promote the formation of Ti₃SiC₂. The density of state shows that there is a mixed conductor character in both of Ti₃SiC₂ and adding Al element. Ti₃SiC₂ is with more tendencies to form a semiconductor. The total density of state near Fermi lever after adding Al is larger than that before adding, so the electric conductivity may increase after adding Al.

Keywords

Ti₃SiC₂ / doping of Al / electronic structure / chemical bond

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