Superconductivity and magnetism in the phase diagram of bulk La2-xCexCuO4+-delta investigated by muon-spin spectroscopy and neutron scattering

通过μ子自旋光谱和中子散射研究块体La2-xCexCuO4-δ相图中的超导性和磁性

• 批准号: 108195470
• 负责人: Professorin Dr. Barbara Albert
• 金额: --
• 依托单位: Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/108195470?language=en
• 关键词: Superconductivity; magnetism; phase; diagram; bulk

Electron doped cuprates are mostly identified with the compounds Nd2-xCexCuO4+-( orPr2-xCexCuO4+-(. The simple reason is that these compounds can be synthesized bymany techniques from thin film methods to single crystal growth. In contrast, the electrondoped cuprate LA2-xCexCuO4+-( is not thermodynamically stable. So far, only thin filmsof La2-xCexCuO4+-( have been available. However, in order to analyze the magnetic andsuperconducting phase diagram in detail, bulk investigation methods as neutron scatteringand muon-spin relaxation and rotation free from thin film effects are indispensable. This iseven more important as the oxygen concentration at the different oxygen sites within thecrystal structure of La2-xCexCuO4+-( is only determinable by neutron scattering. Basedon our recent success to stabilize phase pure bulk La2-xCexCuO4+-( in the unstable T-structureby a low-temperature synthesis method, the phase diagram of La2-xCexCuO4+-( has nowbecome experimentally accessible. For the first time, it has become possible to synthesizebulk La 2-xCexCuO 4+-( , to determine the superconducting and transport properties, whileat the same time for all samples the oxygen site occupation, and the (co)existence ofsuperconducting and magnetic phases can be studied. As a result of this project, anauthoritative phase diagram of La2-x CexCuO 4+-( will be established, as is now availableonly for hole doped compounds such as La 2-xSrxCuO 4+-(.

电子掺杂的铜酸盐主要被鉴定为化合物Nd 2-xCexCuO 4 +-（或Pr 2-xCexCuO 4 +-（。原因很简单，因为这些化合物可以通过从薄膜方法到单晶生长的许多技术来合成。与此相反，电子掺杂的铜酸盐LA 2-xCexCuO 4 +-（）是不稳定的。到目前为止，只有La_（2-x）Ce_xCuO_（4 +-）薄膜可用。然而，为了详细地分析磁性和超导相图，中子散射和μ子自旋弛豫和转动等体研究方法是必不可少的。这一点更为重要，因为La_（2-x）Ce_xCuO_（4 +-）晶体结构中不同氧位的氧浓度只能通过中子散射测定。基于我们最近成功地用低温合成方法将La_（2-x）Ce_xCuO_（4 +-）稳定在不稳定的T型结构中，La_（2-x）Ce_xCuO_（4 +-）的相图现在已经可以在实验上获得。首次合成了La 2-xCexCuO 4+-（1-x）的体相样品，并对其超导和输运性质进行了研究，同时对所有样品的氧位占位以及超导相和磁相的共存进行了研究。本项目的成果是建立了一个权威的La 2-xCexCuO 4+-（）相图，这是目前只有空穴掺杂化合物如La 2-xSrxCuO 4+-（）才能得到的相图。

项目成果

Oxygen stoichiometry of low-temperature synthesized metastable T′-La2CuO4

低温合成亚稳态Tâ2-La2CuO4的氧化学计量

• DOI: 10.1088/0953-2048/26/10/105026
• 发表时间: 2013
• 期刊: Superconductor Science and Technology
• 影响因子: 3.6
• 作者: R. Hord;G. Pascua;K. Hofmann;G. Cordier;J. Kurian;H. Luetkens;V. Pomjakushin;M. Reehuis;B. Albert;L. Alff
• 通讯作者: L. Alff

Thermodynamic study of orthorhombic Tx and tetragonal T′ lanthanum cuprate, La2CuO4

斜方晶系 Tx 和四方晶系 Tâ² 铜酸镧 (La2CuO4) 的热力学研究

• DOI: 10.1016/j.jssc.2013.05.005
• 发表时间: 2013
• 期刊: Journal of Solid State Chemistry
• 影响因子: 3.3
• 作者: K. I. Lilova;R. Hord;L. Alff;B. Albert;A. Navrotsky
• 通讯作者: A. Navrotsky

Synthesis of Microcrystalline Ce2O3 and Formation of Solid Solutions between Cerium and Lanthanum Oxides

• DOI: 10.1002/zaac.201300663
• 发表时间: 2014-05-01
• 期刊: ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
• 影响因子: 1.4
• 作者: Hamm, Christin M.;Alff, Lambert;Albert, Barbara
• 通讯作者: Albert, Barbara