The study on observation technique of orbital orderingby synchrotron radiation, neutron, and electron beams.

同步辐射、中子、电子束轨道有序观测技术研究。

• 批准号: 12304019
• 负责人: MURAKAMI Youichi
• 金额: $ 29.79万
• 依托单位: TOHOKU UNIVERSITY (2001-2002)The High Energy Accelerator Research Organization (2000)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12304019/
• 关键词: Orbital Orderin; Charge Ordering; Quadrupole Ordering; Transition Metal Oxide; Rare Earth Compound; Resonant X-ray Scattering; Magnetic Compton Scattering; Orbital Fluctuation; 軌道秩序

Three degrees of freedom (charge, spin, and orbital) play very important roles in the electronic and magnetic properties in strongly correlated electron systems. Therefore, it is necessary to observe the ordering states of the degrees of freedom. However, the experimental technique to observe the orbital ordering has been very limited compared with the charge and spin ordering. The aim of this study is to develop thetechnique using synchrotron X rays, neutrons, and electron beams.We make five groups to achieve the aim. The followings are the main results for the groups.1. Samples and the evaluations group: We have made good quality samples of transition metal oxides and f-electron systems.2. Synchrotron X rays group: We have developed a new technique to observe ferro-orbital ordering -using the interference of resonant X-ray scattering. Magnetic Compton profile has revealed the orbital state of layered manganites.3. Neutrons group: The polarized neutron diffraction has elucidated the orbital state of layered manganites coupled with the powder neutron iffraction.4. Electron beams group: We have developed the software-of the convergent electron diffraction and made clear the orbital state of the manganite.5. Theory group: We have constructed the general theory of resonant X-ray scattering to observe the orbital ordering and its fluctuation

三个自由度（电荷、自旋和轨道）在强相关电子系统的电子和磁性中起着非常重要的作用。因此，有必要观察自由度的有序状态。然而，与电荷和自旋排序相比，观察轨道排序的实验技术非常有限。本研究的目的是开发使用同步加速器X射线、中子和电子束的技术。我们分为五个组来实现这一目标。以下是各组的主要结果： 1．样品和评估组：我们制作了高质量的过渡金属氧化物和f电子体系样品。 2．同步加速器X射线组：我们开发了一种观察铁轨道有序性的新技术——利用共振X射线散射的干涉。磁康普顿剖面揭示了层状锰酸盐的轨道状态。 3．中子组：偏振中子衍射结合粉末中子衍射阐明了层状锰氧化物的轨道态。 4．电子束组：开发了会聚电子衍射软件，明确了亚锰酸盐的轨道状态。 5．理论组：我们构建了共振X射线散射的一般理论来观察轨道排序及其涨落

项目成果

Y.Moritomo et al.: "Pressure-Induced Insulator-Metal Transition in a Bilayer Manganite : Pressure Control of Orbital Stability"Phys.Rev.B. 62. 17-20 (2000)

Y.Moritomo 等人：“双层锰氧化物中的压力诱导绝缘体-金属转变：轨道稳定性的压力控制”Phys.Rev.B。

K.Ohwada et al.: ""Devil's Staircase"-Type Phase Transition in NaV_2O_5 under High Pressure"Phys.Rev.Lett.. 87. 0864002-1-086402-4 (2001)

K.Ohwada 等：“高压下 NaV_2O_5 中的“魔鬼阶梯”型相变”Phys.Rev.Lett.. 87. 0864002-1-086402-4 (2001)

T.Hashimoto, K.Tsuda, J.Shiono, I Mizusaki, M.Tanaka: "Determination of the crystal system and space group of BaBiO_3 by convergent-beam electron diffraction and x-ray diffraction using synchrotron radiation"Phys.Rev B. 64・22. 224114-1-224114-6 (2001)

T.Hashimoto、K.Tsuda、J.Shiono、I Mizusaki、M.Tanaka：“使用同步辐射通过会聚束电子衍射和 X 射线衍射测定 BaBiO_3 的晶系和空间群”Phys.Rev B. 64・22。224114-1-224114-6（2001）

Sumio Ishihara: "Magnetic Ordering, Orbital Ordering and Resonant X-ray Scattering in Perovskite Titanates"Phys.Rev B. 65. 064442-1-064442-9 (2002)

Sumio Ishihara：“钙钛矿钛酸盐中的磁有序、轨道有序和共振 X 射线散射”Phys.Rev B. 65. 064442-1-064442-9 (2002)

H.Sawa, Y.Murakami et al.: "Low-Temperature Structure of the Quarter-Filled Ladder Compoimd a'-NaV_2O_5"J.Phys.Soc.Jpn.. 71. 385-388 (2002)

H.Sawa, Y.Murakami 等：“四分之一填充梯状化合物 a-NaV_2O_5 的低温结构”J.Phys.Soc.Jpn.. 71. 385-388 (2002)