Interfaces between perovskite oxides have garnered enormous interest in the last decade by featuring several novel aspects such as interfacial coupling, different magnetic order and so on. Therefore, this thesis presents a study of novel structural and magnetic order at coherent oxide interfaces, particularly in La0.7A0.3MnO3/SrRuO3(A=Sr or Ca) and La0.7Ca0.3MnO3/SrTiO3 heterostructures. La0.7A0.3MnO3/SrRuO3 has been of particular interest because of the unusually strong antiferromagnetic coupling at the interfaces between ferromagnetic manganite and ruthenate layers. The structural aspects include elastic strain and, for the La0.7Sr0.3MnO3/SrRuO3interface, the atomic termination plane of the perovskite-type layers at the interface. Elastic strain has been controlled statically through growing the films on different substrates or dynamically by using a piezoelectric substrate.