Theoretical studies on the high-energy excitation spectra of multinary compounds

多元化合物高能激发光谱的理论研究

• 批准号: 15540344
• 负责人: OKADA Kozo
• 金额: $ 1.86万
• 依托单位: Okayama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540344/
• 关键词: electron correlation; high T_c superconductors; photoemission; x-ray absorption; resonant inelastic x-ray scattering; charge transfer; orbital degeneracy; transition-metal compounds; 共鳴X線非弾性散乱; 強相関; フント結合; 非局所遮蔽効果; 酸化物高温超伝導体; X線吸収スペクトル; X線発光

The present research clarified the capability of high-energy spectroscopies as tools to investigate the electronic states of multinary compounds. Particular attention was paid to the theoretical studies on the oxygen 1s resonant x-ray emission spectroscopy (O 1s RXES) of transition-metal oxides. The present theoretical calculations showed that the O 1s RXES provides us with information on the itinerant valence electrons as well as the localized ones. In the case of insulating cuprates for instance, it observes the inelastic x-ray scattering due the electronic transition from the Zhang-Rice singlet band to the upper Hubbard band (UHB). The present research also predicted that the polarization correlation between incident and scatted x-rays is very strong in the O 1s RXES.The present research clarified the electronic state of one-dimensional Y_2BaNiO_5-type nickel compounds. The theoretical calculations on the O 1s RXES and O 1s X-ray absorption spectrum (O 1s XAS) showed that the Hund's … More coupling is very important in understanding the valence electron states. For divalent Ni compounds, the present theory predicted a new type of excitation. It consists of simultaneous double excitations at distant Ni ions, where the Ni 3d spin state of each Ni is changed from triplet to singlet. We also succeeded in observing the excitation in NiO.In order to emphasize the importance of comprehensive analysis of various high-energy spectra, we extended the study to the calculations of Cu 2p x-ray photoemission spectroscopy (Cu 2p XPS), angle-resolved photoemission (ARPES) and Cu 1s resonant inelastic x-ray scattering (Cu 1s RIXS). We also showed a close relationship between the Cu 2p XPS and ARPES through the theoretical calculations on the carrier doping dependence of those spectra Moreover, we studied the effects of Cu 3d orbital degeneracy on the Cu 1s RIXS to show the dd excitation mechanism in the Cu 1s RIXS. The result showed that the excitation selection rules of the Cu 1s RIXS differ from those of the O 1s RXES in many respects. It indicates that the Cu 1s RIXS and O 1s RXES are complementary to each other. Less

本研究阐明了高能谱作为研究多元化合物电子态的工具的能力。重点对过渡金属氧化物的氧1S共振X射线发射光谱(O1S RXES)进行了理论研究。目前的理论计算表明，O1S RXES给我们提供了巡游价电子和定域价电子的信息。例如，在绝缘铜酸盐的情况下，它观察到了由于从张-赖斯单线带到上Hubbard带(UHB)的电子跃迁而产生的非弹性x射线散射。本研究还预测了O1S RXES中入射和散射X射线的偏振相关性很强。本研究阐明了一维Y2BaNiO5型镍化合物的电子态。对O_1S RXES和O_1S X射线吸收谱(O_1S_XAS)的理论计算表明，Hund‘s…更多的耦合对于理解价电子态是非常重要的。对于二价镍化合物，目前的理论预测了一种新的激发类型。它包括在遥远的Ni离子处同时进行双激发，其中每个Ni的Ni3d自旋态由三重态变为单重态。为了强调综合分析各种高能谱的重要性，我们将研究扩展到了Cu2pX射线光电子能谱(Cu2pXPS)、角分辨光电子能谱(ARPES)和Cu1s共振非弹性x射线散射(Cu1sRIXS)的计算。通过对这些光谱的载流子掺杂依赖关系的理论计算，揭示了Cu2pXPS和ARPES之间的密切关系。此外，我们还研究了Cu3d轨道简并对Cu1sRIXS的影响，揭示了Cu1sRIXS中的dd激发机制。结果表明，Cu1SRIXS和O1SRXES的激发选择规则在许多方面都不同。表明Cu1SRIXS和O1SRXS是相辅相成的。较少

项目成果

Localized Nature of Valence-Hole States in Ca_2+xY_2-xCu_5O_10Shown by O 1s XAS

O 1s XAS 显示 Ca_2 xY_2-xCu_5O_10 中价空穴态的局域性质

• 发表时间: 2005
• 期刊: Physica Scripta T115巻
• 作者: K.Mibu.N.Jiko;M.Takeda;N.Jiko et al.;K.Okada
• 通讯作者: K.Okada

Resonant Inelastic X-ray Scattering at the Oxygen K Resonance of NiO : Nonlocal Charge Transfer and Double-Singlet Excitations

NiO 氧 K 共振处的共振非弹性 X 射线散射：非局域电荷转移和双单线态激发

• 发表时间: 2006
• 期刊: Physical Review Letters 96巻
• 作者: L.-C.Duda

Large-cluster-model calculation of O 1s XAS for Y_2-xCa_xBaNiO_5

Y_2-xCa_xBaNiO_5 O 1s XAS 的大团簇模型计算

• 发表时间: 2005
• 期刊: Journal of Electron Spectroscopy and Related Phenomena 144-147巻
• 作者: K.Mibu.N.Jiko;M.Takeda;N.Jiko et al.;K.Okada;N.Jiko et al.;M.Takeda et al.;K.Okada
• 通讯作者: K.Okada

Copper K and Oxygen K Resonant Inelastic X-ray Scattering of One-Dimensional Cuprates

一维铜酸盐的铜 K 和氧 K 共振非弹性 X 射线散射

• 发表时间: 2006
• 期刊: Journal of the Physical Society of Japan 75巻
• 作者: L.-C.Duda;K.Okada
• 通讯作者: K.Okada

Large-cluster-model calculation of O1s XAS for Y_<2-x>Ca_xBaNiO_5

Y_<2-x>Ca_xBaNiO_5 的 O1s XAS 大团簇模型计算

• 发表时间: 2005
• 期刊: Journal of Electron Spectroscopy and Related Phenomena 144-147
• 作者: E.Kabasawa;J.Nakamura;T.Morimoto;N.Yamada;K.Kuroki;H.Yamazaki;K.Okada;K.Oka;Y.Tezuka;J.D.Denlinger;R.C.C.Perera;K.Okada;K.Okada
• 通讯作者: K.Okada