Electronic Structure and Magnetic Properties of the Al-doped Fe3O4 Studied by X-ray Absorption Spectroscopy and Magnetic Circular Dichroism

• Main Authors: Chih-Kuang Yang, 楊智光
• Other Authors: W. F. Pong
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/08559157885472252258

碩士 === 淡江大學 === 物理學系 === 92 === The electronic structure and magnetic properties of Al(x)-doped Fe3O4 films at various Al concentrations were investigated using the Al and O K-edges x-ray absorption near-edge structure (XANES) and Fe L3,2-edge magnetic circular dichroism (MCD). The O K-edge XANES spectra reveal that the intensity of O 2p-Fe 3d hybridized states decreases linearly as the Al concentration increases, suggesting that non-magnetic Al substitution reduces the coupling of O 2p with Fe 3d orbitals. The Fe L3-edge MCD spectra also reveal that the intensity of MCD decreases as the Al concentration increases, indicating that Al+3 ions substitute for mainly Fe2+ and Fe3+ ions on the octahedral B-site in the Fe3O4. Theoretical calculations based on the first-principles pseudopotential method using the spin-polarized local density approximation are consistent with the MCD observations.