Pseudo-stripe ordering and its fluctuations in CMR manganites

CMR锰矿的伪条带排序及其波动

• 批准号: 14540326
• 负责人: YOSHIZAWA Hideki
• 金额: $ 2.18万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540326/
• 关键词: stripe order; charge order; Neutron diffraction; 中性子回折

In order to elucidate the mechanism of the colossal magnetoresistance, we have been studying charge/orbital ordering with use of neutron scattering technique. We also studied pseudo-stripe ordering and checkerboard charge ordering in two dimensional Ni oxides.In the study of the (A_1-xB_x)MnO_3 tyoe manganites, we separately studied the effect of randomness in the A/B ion site by preparing the alternately ordered layered manganites in which layers of wither A ions stack alternately. This class of manganites with no A-site randomness shows the highest charge ordering transition temperature. In addition, we discovered that the charge ordering transition and the structural transition take place independently.By the study of the two dimensional Ni oxide La_2-xSr_xNiO_4, we discovered that the checkerboard type charge order is formed at〜480K, but it is replaced by the stripe type spin/charge ordering at low temperatures. the insulator to metal transition in this material is driven not by the stripe order but by the CB charge order.

为了阐明庞磁电阻的机制，我们一直在研究电荷/轨道有序使用中子散射技术。在对（A_1-x B_x）MnO_3型锰氧化物的研究中，我们通过制备交替有序的层状锰氧化物，研究了A/B离子位的随机性对有序度的影响。这类锰氧化物没有A位随机性，显示出最高的电荷有序化转变温度。通过对二维Ni氧化物La_2-xSr_xNiO_4的研究，发现在480 K左右形成棋盘型电荷有序，而在低温下被条纹型自旋/电荷有序所取代。该材料中的绝缘体到金属的转变不是由条纹顺序而是由CB电荷顺序驱动的。

项目成果

H.Kawano-Furukawa et al.: "Anomalous phonon peak in the superconducting state of ErNi_2^11B_2C_2"Phys.Rev.B. 66. 212503-1-212503-4 (2002)

H.Kawano-Furukawa 等人：“ErNi_2^11B_2C_2 超导态中的反常声子峰”Phys.Rev.B。

J.A.Fernandez-Baca 他: "Microscopic spin interactions in colossal magnetoresistance manganites"Phys.Rev.B. 66. 054434(1)-054434(5) (2002)

J.A.Fernandez-Baca 等人：“巨型磁阻锰氧化物中的微观自旋相互作用”Phys.Rev.B 66. 054434(1)-054434(5) (2002)

M.Kubota 他: "Highly Degenerate Canted Spin Structure in Bilayer Manganite La_<1.1>Sr_<1.9>Mn"Phys.Rev.Lett.. 91. 047201-1-047201-4 (2003)

M. Kubota 等人：“双层锰矿 La_<1.1>Sr_<1.9>Mn 中的高度简并倾斜自旋结构”Phys.Rev.Lett.. 91. 047201-1-047201-4 (2003)

R.Kajimoto 他: "Spontaneous rearrangement of the checkerboard charge order to stripe order in La_<0.5>Sr_<0.5>NiO_4"Phys.Rev.B. 67. 014511-1-014511-5 (2003)

R. Kajimoto 等人：“La_<0.5>Sr_<0.5>NiO_4 中棋盘格电荷顺序自发重排为条纹顺序”Phys.Rev.B. 67. 014511-1-014511-5 (2003)

H.Kawano-Furukawa 他: "Anomalous phonon peak in the superconducting state of ErNi_2 ^<11>B_2C"Phys.Rev.B. 66. 212503-1-212503-4 (2002)

H. Kawano-Furukawa 等人：“ErNi_2 ^<11>B_2C 超导状态下的异常声子峰”Phys.Rev.B. 66. 212503-1-212503-4 (2002)