Secondary-phase precipitation and surface morphology variations in photolithographically patterned YBa_2Cu_3O_7-x/PrBa_2Cu_3O_7-x multilayer device structures

摘要

The microstructure of photolithographically patterned YBa_2Cu_3O_7-x/PrBa_2Cu_3O_7-x thin film multilayer devices,deposited onto MgO substrates by electron-beam co-evaporation,has been examined using scanning and transmission electron microscopy techniques.Although c-oriented growth over step-regions is observed,a 'holey' free-surface morphology results.The free-surface holes are associated with,and presumable caused by,defects within the 'bulk' of the films.These defects include CuYO_2 precipitates and a-oriented/45~0 rotated c-oriented YBCO/PrBCO.