PUB - Publikationen an der Universität Bielefeld

MgB2 is an intermetallic compound with a high critical temperature of Tc=40 K. The simple crystal structure, large coherence length and the high critical current density makes thin magnesium diboride films attractive for superconducting applications like Josephson junctions. To fabricate thin MgB2 films, we used a magnetron co-sputtering system with a Mg and a B target respectively. The films were deposited by dc-magnetron sputtering of Mg and rf-magnetron sputtering of B at a low substrate temperature between 210 circle C and 260 circle C without a post annealing process. The differences in vacuum pressure between Mg and B make it essential that the composition ratio is controlled by different sputtering power of each target. The crystal structure was measured by X-ray diffraction and transport investigations at low temperatures were performed.