In the paper, density of states, band structure and electron density difference of Zn1-xCdxO are calculated by first principles, here x varies from 0 to 0.75 at intervals of 0.125, and the band gap obtained from band ...In the paper, density of states, band structure and electron density difference of Zn1-xCdxO are calculated by first principles, here x varies from 0 to 0.75 at intervals of 0.125, and the band gap obtained from band structure changes from 0.968 eV to 0.043 eV. The lattice strain and p-d repulsion theory are used to investigate variation of the band gap, the results obtained show that the variation is mainly due to the lattice tensile strain. The p-d repulsion in Zn1-xCdxO cannot be neglected. In addition, electron density difference can be used to verify the results.展开更多
Using the first principle method based on density functional theory, this paper studies the electronic structure and the ferromagnetic stability in N-doped ZnO. The calculated results based on local density approximat...Using the first principle method based on density functional theory, this paper studies the electronic structure and the ferromagnetic stability in N-doped ZnO. The calculated results based on local density approximation （LDA） and LDA＋U method show that ferromagnetism coupling between N atoms is more energetically favourable for eight geometrically distinct configurations. The dominant ferromagnetic interaction is due to the hybridization between O 2p and N 2p. The origin of the ferromagnetic state in N doped ZnO is discussed by analysing coupling between N 2p levels. We also analyse N dopant concentration and lattice strain effect on ferromagnetism.展开更多
文摘In the paper, density of states, band structure and electron density difference of Zn1-xCdxO are calculated by first principles, here x varies from 0 to 0.75 at intervals of 0.125, and the band gap obtained from band structure changes from 0.968 eV to 0.043 eV. The lattice strain and p-d repulsion theory are used to investigate variation of the band gap, the results obtained show that the variation is mainly due to the lattice tensile strain. The p-d repulsion in Zn1-xCdxO cannot be neglected. In addition, electron density difference can be used to verify the results.
基金Project supported by the Science Foundation from the Educational Department of Liaoning Province of China (Grant No. L2010003)
文摘Using the first principle method based on density functional theory, this paper studies the electronic structure and the ferromagnetic stability in N-doped ZnO. The calculated results based on local density approximation （LDA） and LDA＋U method show that ferromagnetism coupling between N atoms is more energetically favourable for eight geometrically distinct configurations. The dominant ferromagnetic interaction is due to the hybridization between O 2p and N 2p. The origin of the ferromagnetic state in N doped ZnO is discussed by analysing coupling between N 2p levels. We also analyse N dopant concentration and lattice strain effect on ferromagnetism.
