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. ***
