The microstructure of interfacial defects in YBa2Cu3O7-/SrTiO3(001) heterostructures has been investigated by aberration-corrected ultrahigh-resolution electron microscopy. We determine that c-axis-oriented YBa2Cu3O7- thin films epitaxially grow on SrTiO3(001) with two types of interface structure. The coalescence of nucleation sites with different types of interface structure leads to the formation of antiphase domain boundaries in YBa2Cu3O7- thin films, which terminate at planar faults with different configurations near the interface. Stand-off misfit dislocations are observed and the dislocation core structure is explored. Based on the interface structure and interfacial defects, the initial growth mode of YBa2Cu3O7- thin films on SrTiO3(001) is discussed.
[mi, shao-bo] res ctr juelich, inst solid state res, d-52425 julich, germany. [mi, shao-bo] res ctr juelich, ernst ruska ctr microscopy & spect electrons er c, d-52425 julich, germany. [mi, shao-bo] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.
; mi, sb (reprint author), res ctr juelich, inst solid state res, d-52425 julich, germany.