  Perovskite oxide heteroepitaxy receives much attention because of the
possibility to com- bine the diverse functionalities of perovskite oxide
building blocks. A general boundary con- dition for the epitaxy is the presence
of polar discontinuities at heterointerfaces. These polar discontinuities
result in reconstructions, often creating new functionalities at the interface.
However, for a significant number of materials these reconstructions are
unwanted as they alter the intrinsic materials properties at the interface.
Therefore, a strategy to eliminate this reconstruction of the polar
discontinuity at the interfaces is required. We show that the use of
compositional interface engineering can prevent the reconstruction at the
La0.67Sr0.33MnO3/SrTiO3 (LSMO/STO) interface. The polar discontinuity at this
interface can be removed by the insertion of a single La0.33Sr0.67O layer,
resulting in improved interface magnetization and electrical conductivity.
