Investigation of the Electronic Structure of High Temperature Superconductors and Related Materials

9311566沈阳高能量分辨率角分辨光电子能谱测量将在高质量的单晶样品上进行。样品的掺杂将允许改变T_c。光电子能谱研究的目的是了解高温超导材料中的带隙各向异性，在这些材料中，将利用改进的能量和角分辨率。Bi2212的研究将扩展到YBCO、TI2212、TI2201和NCCO。对正常态的研究将把光电发射测量结果与旨在了解Mott绝缘体掺杂行为的输运数据相关联。高效率的芯能级光电子能谱将被用来研究由于超导带隙打开而引起的局域电子结构的变化。关于氧在决定过渡金属和过渡金属氧化物电子结构差异中的作用，将研究在正常金属/超导体界面和铁磁材料附近所研究的邻近效应。%光电子能谱是一种强大的实验工具，它利用入射辐射使电子载流子从固体中射出。测量发射的能量和角度可以得到有关固体电子结构的重要信息。光电子能谱技术已被证明是研究高温超导体电学性质的一种很好的技术。在本研究中，这项技术被扩展到各种不同的材料，这些材料可以作为非常高质量的单晶样品。在这项工作中将使用一种改进很多的分光计。这项技术将扩展到其他材料，特别是铁磁性固体。特别令人感兴趣的将是比较过渡金属，如镍和铁及其各自的氧化物。***

9311566 Shen High energy resolution angle-resolved photoemission measurements will be carried out on high quality single crystal samples. Doping of the samples will allow to vary Tc. The photoemission studies are aimed at understanding the gap anisotropy in HTS materials where an improved energy and angular resolution will be utilized. The study of Bi2212 will be extended to YBCO, TI2212, TI2201, and NCCO. Studies of the normal state will correlate the results of photoemission measurements with transport data aimed at understanding the doping behavior of Mott insulators. High efficiency core level photoemission spectroscopy will be used to investigate changes in the local electronic structure due to the opening of the superconducting gap. The proximity effect studied near normal metal/superconductor interfaces and ferromagnetic materials will be investigated with respect to the role of oxygen in determining differences in the electronic structure of transition metals and transition metal oxides. %%% Photoemission is a powerful experimental tool in which impinging radiation leads to the ejection of electronic carriers from a solid. Measurement of the energy and angle of emission can yield important information about the electronic structure of the solid. The photoemission technique has proved to be an excellent technique to study the electronic properties of high temperature superconductors. In the present study the technique is extended to various different materials which are available as very high quality single crystal samples. A much improved spectrometer will be employed in this work. The technique will be extended to other materials, notable ferromagnetic solids. Of particular interest will be to compare transition metals such as nickel and iron with their respective oxides. ***