Charge and Spin Ordering in Layered Perovskite-type Oxide Studied by Synchrotron X-ray Diffraction

通过同步加速器 X 射线衍射研究层状钙钛矿型氧化物中的电荷和自旋排序

• 批准号: 09440144
• 负责人: MURAKAMI Youichi
• 金额: $ 8.32万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440144/
• 关键词: Strongly Correlated Electron System; Manganite; Charge Ordering; Orbital Ordering; Synchrotron Radiation; X-ray Diffraction; Resonant X-ray Scattering; Perovskite; X線共鳴散乱

Recently, it has been recognized that the charge, spin, and orbital degrees of freedom play important roles in the electric and magnetic properties of the transition-metal oxides. In perovskite-type manganited, especially, the discover of a wide variety of magnetic-field-induced phenomena, such as a colossal magnetoresistance and a magnetostructural transition, has stimulated much activity this field. The spin and charge ordering can be directly observed by neutron and electron diffraction, and some other techniques. The experimental technique to observe the orbital ordering, however, has been limited. Here, we have developed a resonant x-ray scattering technique to detect the orbital ordering directly.We have succeeded to observe many types of charge, spin, and orbital ordering states in perovskite oxides as well as a f-electron systems by using the resonant x-ray scattering. Recent great achievements are an observation of short-range ordering of charge and orbital and a observation of orbital-superlattice in an artificial lattice. The mechanism of the charge and orbital ordering has been elucidated by the observation of the short-range order. Meanwhile, it is expected that we can find a way of making electric devices with an artificial lattice by the observation of the orbital-superlattice.

最近，人们认识到电荷、自旋和轨道自由度在过渡金属氧化物的电学和磁学性质中起着重要作用。特别是在钙钛矿型锰化物中，各种磁场感应现象的发现，例如巨大的磁阻和磁结构转变，刺激了该领域的许多活动。自旋和电荷排序可以通过中子和电子衍射以及一些其他技术直接观察。然而，观察轨道排序的实验技术受到限制。在这里，我们开发了一种共振X射线散射技术来直接检测轨道有序性。通过使用共振X射线散射，我们成功地观察到了钙钛矿氧化物以及f电子系统中多种类型的电荷、自旋和轨道有序态。最近的重大成就是对电荷和轨道的短程有序的观察以及对人造晶格中轨道超晶格的观察。通过对短程有序的观察，已经阐明了电荷和轨道有序的机制。同时，通过对轨道超晶格的观察，我们有望找到一种用人工晶格制造电子器件的方法。

项目成果

村上洋一 他: "結晶解析ハンドブック第IV編第4章"共立出版株式会社. 673 (1999)

村上洋一等：《晶体分析手册第 IV 卷第 4 章》共立出版有限公司 673（1999）

M. V. Zinunermann et. al.: "INTERPLAY BETWEEN CHARGE, ORBITAL, AND MAGNETIC ORDER IN Pr_<1-x>Ca_xMnO_3"Phys. Rev. Lett.. 83. 4872-4875 (1999)

M.V. Zinunermann 等。

Y. Endoh et. al.: "TRANSITION BETWEEN TWO FERROMAGNETIC STATES DRIVEN BY ORBITAL ORDERING IN La_<0.88>Sr_<0.12>MnO_3"Phys. Rev. Lett.. 82. 4328-4331 (1999)

Y.Endoh 等。

村上洋一 他: "結晶解析ハンドブック"共立出版株式会社. 673 (1999)

村上洋一等：《晶体分析手册》共立出版673（1999）

村上洋一 他: "新しい放射光科学第5章共鳴X線散乱で見る軌道秩序"講談社サイエンティフィック株式会社(印刷中). (2000)

Yoichi Murakami 等：“新同步辐射科学第 5 章通过共振 X 射线散射观察到的轨道顺序”讲谈社科学有限公司（2000 年出版）。