Magnetic properties of an SrMnO$_3$/La$_{0.7}$Sr$_{0.3}$MnO$_3$ heterostructure on an NdGaO$_3$ substrate

An epitaxial heterostructure based on strontium and lanthanum-strontium manganite films (SrMnO$_3$ and La$_{0.7}$Sr$_{0.3}$MnO$_3$) is studied. Ferromagnetic resonance spectra, angular dependences of the resonance field for different temperatures, in-plane and cubic anisotropy as well as the temperature dependences of the magnetization, were measured. The obtained magnetic parameters of the heterostructure were compared with the magnetic parameters of a single La$_{0.7}$Sr$_{0.3}$MnO$_3$ film. We assume that the existence of an interlayer exchange at the ferromagnet-antiferromagnet interface at low temperatures leads to the appearance of unidirectional anisotropy in the heterostructure SrMnO$_3$/La$_{0.7}$Sr$_{0.3}$MnO$_3$. We believe that the presented results will be useful for the practical development of antiferromagnet-based ultrafast devices: emitters, amplifiers, detectors.