Intermixing and charge neutrality at DyScO3/SrTiO3 interfaces

Recently, interfaces between complex insulating oxides have attracted much attention due to their broad spectrum of electronic properties. Joining two materials of different polarity can provide highly conducting layers. The polar discontinuity delivers the driving force for a charge accumulation in the interfacial region which has been demonstrated for lanthanum-based perovskite interfaces with SrTiO3. Here it is shown that the polar discontinuity can be accommodated by variations in composition of cation lattice planes at the polar oxide interface between DyScO3 and SrTiO3, where DyScO3 holds the same polarity as the lanthanum-based perovskites. An intermixing extending over two monolayers at the interfaces for both the Dy–Sr sublattice and the Sc–Ti sublattice is quantified. As a result, charge neutrality is established by electrical compensation between neighbouring atomic planes.