PRASEODYMIUM ALLOY ION-SOURCE FOR FOCUSED ION-BEAM IMPLANTATION IN SUPERCONDUCTORS

We have investigated the emission characteristics of a liquid alloy io n source for focused ion beam implantation of praseodymium (Pr) ions i n high-T-c superconductors. The element Pr was used in a ternary Au-Si -Pr alloy with a low melting point and a low vapour pressure. The melt ing properties of the alloy were determined by differential thermal an alysis. We have measured the emission current stability, the current-v oltage characteristics and the mass spectra using a single magnetic ma ss spectrometer. The ion source exhibits a good performance even after storage for several months in air. The mass spectra show a high inten sity of double charged Pr ions. (C) 1996 American Institute of Physics .