Electronic Structures and Chemical Bonds of Cobaltite and Ni-Doped

摘要

The relation among electronic structure, chemical bond and thermoelectric property of Ca3Co2O6 and Ni-doped was studied by density function theory and discrete variation method（DFT-DVM）. The results indicate that the highest valence band（HVB） and the lowest conduction band（LCB） are mainly attributed to Co3d, Ni3d and O2p atomic orbitals. The property of a semiconductor is shown from the gap between HVB and LCB. The gap of Ni-doped one is less than that of Ca3Co2O6. The non-metal bond or ceramic characteristic of Ni-doped one is weaker than that of Ca3Co2O6, but the metal characteristics of Ni-doped one are stronger than those of Ca3Co2O6. The thermoelectric property should be improved by adding Ni element into the system of Ca3Co2O6.