Formation of Stacking-Faults in Atomic Graphoepitaxial a-Axis YBa2Cu3Ox Thin Films on (100) SrLaGaO4 Substrates

Abstract
The complicated crystalline microstructure of c-axis in-plane-aligned, a-axis oriented YBa2Cu3O x thin films on K2NiF4-type (100) SrLaGaO4 substrates is discussed in relation to surface irregularities inherent in the (100) SrLaGaO4 substrate. Transmission electron microscopy reveals that interlattice planes of YBa2Cu3O x shift by multiples of c/6 unit, resulting in anti-phase domain boundaries and stacking-faults. The formation of these defects can be correlated with the cobbled substrate surface and is modeled in terms of atomic steps on the cobbled surface based on our growth model named “atomic graphoepitaxy”.