The Effect of the Interface Width on the Exchange Interaction Constant between Ferro- and Antiferromagnets

In the approximation of the average spin method, a system of equations for determining the average magnetic moments of atoms at the interface between a ferromagnet and an antiferromagnet is formulated. It is possible to simulate the dependences of interfacial exchange interaction constant A(in) on the temperature, antiferromagnetic layer thickness, and interface width by solving the system of equations for an ultrathin Ni/NiO film. It is found that the interfacial exchange interaction constant in a film with a fixed interface width at low temperatures increases with an increase in the thickness of the antiferromagnetic layer. With an increase in the interface width, the A(in) value decreases by a factor of 1.3 and reaches its minimum level.