The problem with the copper Auger data for the high temperature superconductors

Abstract

A summary of the L 3 VV Auger data reported for the high temperature superconductors is given. The variations and trends in the data for different materials and processing conditions are contrasted with those reported for the L 3 VV line shape of the copper dihalides and for the L 3 M 23 V Auger line shape of the superconductors. At least four different mechanisms involving shakeup or shakeoff in the intermediate core-hole state or in the Auger final state have been given in the literature to explain the existence of the satellite in the L 3 VV line shape. Contrasts are made with how this satellite varies compared with the XPS core level satellite. Advantages and drawbacks of each proposed mechanism are given, with the final state mixing model favored; but no firm conclusions are reached on which mechanism is acting.