Effects of Breit interaction on the L-2,L-3 x-ray absorption near-edge structures of 3d transition metals

L2, 3 x-ray absorption near-edge structures (XANES) of 3d transition metal (TM) ions and their compounds are calculated by the all-electron relativistic configuration interaction method. The Breit interaction term, which is the first relativistic correction term for the electron-electron interaction in the quantum electrodynamics, is taken into account in the many-electron Hamiltonian. Then the effects on the multiplet structure for 3d TM L2, 3 XANES are investigated. The energy separation between L3 and L2 edges of theoretical spectrum decreases when the Breit interaction term is taken into account. At the final states of L2, 3 XANES, the Breit interaction energies linearly depend on the occupation number of TM 2p3/2 orbitals. They are not influenced by the valency and the crystal field. This main contribution of the Breit interaction term is, therefore, calculated to be the reduction of the separation between L3 and L2 edges, which ranges from 0.49 to 1.52 eV for Sc to Cu

3d センイ キンゾク カゴウブツ ニ オケル L2 3 Xセン キュウシュウ スペクトル ノ ソウタイロン タデンシ ケイサン

京都大学0048新制・課程博士博士(工学)甲第13010号工博第2752号新制||工||1400(附属図書館)UT51-2007-H283京都大学大学院工学研究科材料工学専攻(主査)教授 田中 功, 教授 河合 潤, 教授 田村 剛三郎学位規則第4条第1項該当Doctor of EngineeringKyoto UniversityDFA

Ab initio charge transfer multiplet calculations on the L_{2,3} XANES and ELNES of 3d transition metal oxides

The L_{2,3} x-ray absorption near-edge structures (XANES) and electron energy loss near-edge structures (ELNES) of 3d transition metal (TM) oxides are systematically calculated by the ab initio charge transfer multiplet (CTM) method using fully relativistic molecular spinors on the basis of density-functional theory. The electronic excitation from molecular spinors mainly composed of O-2p to those of TM-3d, that is, charge transfer, is included by considering additional electronic configurations in the configuration interactions. The effects of the covalency and charge transfer on the TM-L_{2,3} XANES are investigated in detail. The power of the ab initio CTM method to quantitatively reproduce the spectra is demonstrated. Meanwhile, limitations of the application of the method are discussed

Effects of Breit interaction on the L-2,L-3 x-ray absorption near-edge structures of 3d transition metals

L2, 3 x-ray absorption near-edge structures (XANES) of 3d transition metal (TM) ions and their compounds are calculated by the all-electron relativistic configuration interaction method. The Breit interaction term, which is the first relativistic correction term for the electron-electron interaction in the quantum electrodynamics, is taken into account in the many-electron Hamiltonian. Then the effects on the multiplet structure for 3d TM L2, 3 XANES are investigated. The energy separation between L3 and L2 edges of theoretical spectrum decreases when the Breit interaction term is taken into account. At the final states of L2, 3 XANES, the Breit interaction energies linearly depend on the occupation number of TM 2p3/2 orbitals. They are not influenced by the valency and the crystal field. This main contribution of the Breit interaction term is, therefore, calculated to be the reduction of the separation between L3 and L2 edges, which ranges from 0.49 to 1.52 eV for Sc to Cu

Complementary evaluation of structure stability of perovskite oxides using bond-valence and density-functional-theory calculations

Estimation of structure stability is an essential issue in materials design and synthesis. Global instability index (GII) based on bond-valence method is applied as a simple indication, while density functional theory calculation is adopted for accurate evaluation of formation energy. We compare the GII and total energy of typical ABO3-type perovskite oxides and rationalize their relationship, proposing that the criteria for empirically unstable structures (GII > 0.2 valence unit) correspond to the difference in total energy of 50–200 meV per formula unit