Vortex dynamics in high-temperature superconducting yttrium barium copper oxide

Thin film growth of in-situ superconducting YBCO is discussed. Microstructure characterization and electrical measurements are presented. Angular dependent transport measurements were performed in high magnetic fields H ;As-deposited superconducting films were prepared using two techniques, sputtering and electron beam coevaporation. The microstructure of the films grown by the different methods is studied using AFM, STM, SEM, and various x-ray analyses. Electron beam evaporated films exhibited c-axis growth and no grain boundaries, while sputtered films show a grain structure. However, x-ray results show that the sputtered films are also entirely c-axis oriented. These different microstructures have significant implications in the vortex dynamics. Electronic transport measurements show that the films are very high quality, although the sputtered films typically have zero resistivity approximately 1K higher than the evaporated films.;A low temperature cryostat was constructed specifically to make angle dependent transport measurements on high T...