Abstract:

A fully oxygen-compatible ion-beam sputter deposition process (IBS) has been implemented for investigation of four film/substrate couples: (103)/(110)YBCO on (110)SrTiO3 (STO) and on (100)NdGaO3 (NGO), and (100)/(010)YBCO on (110)NGO and on (100)STO. For comparison, some (103)/(110)YBCO films have also been prepared by off-axis rf-magnetron sputtering. Below about 600 °C semiconducting, sub-nm flat, and perfectly single-crystalline YBCO films crystallize on these substrates with a crystallographic unit cell of about 1/3 of the Cu-O subcell of YBCO and perfect registration with the Ti4+-O and Ga3+-O sublattice of STO and NGO, respectively. At higher temperature superconducting YBCO films grow coherently epitaxially in the first....