Abstract
The initial stages of deposition of a,b-axis-oriented YBa2Cu3O7-δ onto LaAlO3 substrates have been examined using transmission-electron microscopy. These films have their c axis parallel to the plane of the substrate throughout their thickness, including at the film-substrate interface: no initial layer with the c axis perpendicular to the plane of the substrate is observed. Nucleation of the c-parallel material is extremely dense, such that the triple perovskite layering along the c axis is sometimes disrupted, leading to structures containing two or four perovskite blocks instead of the usual three. By a film thickness of 8 nm the proper YBa2Cu3O7-δ structure has stabilized, although the domain size is still very small, on the order of four unit cells in the c^ direction, or 4.7 nm. Two ledge structures are observed in projection on the film surface: (100)/(001) faces and (110)/(013) faces.
Original language | English |
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Pages (from-to) | 11431-11438 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 47 |
Issue number | 17 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |