Neutron Scattering Study of the One-dimensional Magnetic Anisotropy on the CuO_2 Plane of the Domain-controlled High T_c Superconductors

域控高温超导体CuO_2面一维磁各向异性的中子散射研究

• 批准号: 15340109
• 负责人: HIROTA Kazuma
• 金额: $ 9.54万
• 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 (B)
• 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/grant/KAKENHI-PROJECT-15340109/
• 关键词: high T_c superconductivity; La_<2-x>Sr_xCuO_4; Neutron scattering; One-dimensional spin modulation; Spin dynamics; Bi high T_c superconductors; Impurity effect; Bi_2Sr_<2-x>La_xCuO_6; Bi_2Sr_2CaCu_2O_8; Dewtinning; La_<2-x>Sr_XCuO_4

Since it is difficult to grow large single crystals for highly anisotropic or domain-controlled high T_c superconductors, it is necessary to increase the effective volume by aligning multiple crystals to carry out neutron scattering. We thus have established a method to align many single crystals precisely and efficiently : Combination of a high-energy x-ray diffractometer and a CCD camera, as well as a supersensitive CCD camera with neutron scintillator have been developed. We have succeeded in obtaining the effective volume of 0.53cc by aligning six Bi2212 single crystals with a very high precision, which is about eight times as large as a typical sample volume in previous studies. We have been carrying out series of neutron scattering experiments at the Oak Ridge National Laboratory through the US-Japan cooperative program on neutron scattering to search for the magnetic excitation and the resonance peak.To elucidate the relation between superconductivity and antiferromagnetic spin dynamics, we have performed a systematic inelastic neutron scattering concerning the suppression of T_c by impurities and the change of the spin excitations, using optimally doped La_<2-x>Sr_xCuO_4 single crystals with very small amount of impurities. We have focused upon the non-magnetic impurity Zn and the magnetic impurity Ni : Since the former suppresses T_c more effectively the latter, we expected to clarify how the magnetism is related to the T_c suppression mechanism by comparing both the systems. As to the Zn doped system, a novel in-gap state appears in the middle of the previously know spin gap while the overall spin dynamics does not change much. On the other hand, the spin dynamics of the Ni doped systems is renormalized to the lower energies as T_c is suppressed. It is now clear that the Zn and Ni doping effects on the superconductivity on the CuO_2 plane is qualitatively different.

对于各向异性强或畴控制的高T_c超导体，由于难以生长大单晶，需要通过排列多个晶体来增加有效体积，进行中子散射。因此，我们已经建立了一种方法，以准确和有效地排列许多单晶：组合的高能X射线衍射仪和CCD相机，以及超灵敏的CCD相机与中子闪烁体已经开发。我们已经成功地获得了0.53cc的有效体积，通过对齐六个Bi 2212单晶具有非常高的精度，这是约8倍，在以前的研究中，一个典型的样品体积。我们在橡树岭国家实验室通过美日合作的中子散射计划进行了一系列的中子散射实验，以寻找磁激发和共振峰，为了阐明超导性与反铁磁自旋动力学的关系，我们进行了系统的非弹性中子散射，涉及杂质对T_c的抑制和自旋激发的变化，采用最佳掺杂的La_<2-x>Sr_xCuO_4单晶，杂质含量很低。我们着重研究了非磁性杂质Zn和磁性杂质Ni：由于前者比后者更有效地抑制T_c，我们期望通过比较两个系统来阐明磁性与T_c抑制机制之间的关系。对于Zn掺杂的体系，在已知的自旋能隙中间出现了一个新的能隙内态，而自旋动力学没有太大的变化。另一方面，Ni掺杂体系的自旋动力学被重整化到较低的能量，因为T_c被抑制。Zn和Ni掺杂对CuO_2面超导电性的影响是不同的。

项目成果

Stoner gap in the superconducting ferromagnet UGe_2

超导铁磁体 UGe_2 中的斯托纳间隙

• 发表时间: 2006
• 期刊: Phys. Rev. B 73
• 作者: Ryouji Matsuda;Akinobu Kanda;Youiti Ootuka;R.A.Ribeiro;N.Aso et al.
• 通讯作者: N.Aso et al.

^<17>O NMR study of the inhomogeneous electronic state in La_<2-x>Sr_xCuO_4 crystals^1

^<17>O NMR研究La_<2-x>Sr_xCuO_4晶体中非均匀电子态^1

• 发表时间: 2005
• 期刊: Physical Review B 72
• 作者: P.M.Singer;T.Imai;F.C.Chou;K.Hirota;M.Takaba;T.Kakeshita;H.Eisaki;S.Uchida
• 通讯作者: S.Uchida

Neutron diffraction study on the antiferromagnetic insulating ground state of b-Na_<033>V_2O_5

b-Na_<033>V_2O_5反铁磁绝缘基态的中子衍射研究

• 发表时间: 2005
• 期刊: Journal of the Physical Society of Japan 74
• 作者: S.Nagai;M.Nishi;K.Kakurai;Y.Oohara;H.Yoshizawa;H.Kimura;Y.Noda;B.Greiner;T.Yamauchi;J.Yamamura;M.Isobe;Y.Ueda;K.Hirota
• 通讯作者: K.Hirota

Hole concentration dependence of Mn e(g) orbital state in bilayer manganites studied by magnetic Compton profile measurement

通过磁康普顿剖面测量研究双层锰氧化物中 Mn e(g) 轨道状态的空穴浓度依赖性

• 发表时间: 2005
• 期刊: PHYSICAL REVIEW B 66(12)
• 作者: Koizumi;A;Nagao;T;Kakutani;Y;Hiraoka;N;Sakai;N;Arima;T;Hirota;K;Murakami;Y
• 通讯作者: Y

Electronic excitations in hole-doped La_<1-x>Sr_xMnO_3 studied by resonant inelastic X-ray scattering.

通过共振非弹性X射线散射研究了空穴掺杂La_<1-x>Sr_xMnO_3中的电子激发。

• 发表时间: 2005
• 期刊: J. Phys. Chem. Solids 66
• 作者: K.Ishii;T.Inami;K.Ohwada;K.Kuzushita;J.Mizuki;Y.Murakami;S.Ishihara;Y.Endoh;S.Maekawa;K.Hirota;Y.Moritomo
• 通讯作者: Y.Moritomo