LAUSR

We fabricated and characterized a weakly coupled magnetic Josephson junction based on epitaxial NbN/Ni60Cu40/NbN trilayer heterostructures on single crystal MgO (100) substrates. X-ray diffraction and cross-sectional scanning transmission electron microscopy were used to verify the epitaxial growth of NbN/Ni60Cu40/NbN trilayer, while the ferromagnetic properties of NiCu on NbN film were recorded by plotting the magnetization as a function of both the temperature and the magnetic field strength. The NbN/Ni60Cu40/NbN junctions demonstrated typical Josephson effect with a nonlinear overdamped current–voltage characteristic and a characteristic voltage of 9.1 μV. The magnetic field dependence of the junction critical current showed a nearly ideal Fraunhofer-like pattern with a magnetic field shift of about 12 Oe due to the remanent magnetization of Ni60Cu40 layer.