Determination of magnetic coupling from torque curve

Abstract

Torque relations have been derived as a function of the coupling strength for an interfacially coupled two-layer magnetic system. The two layers are considered to be single crystal thin films characterized by uniaxial and cubic magnetocrystalline anisotropies. Both ferromagnetic and antiferromagnetic coupling cases have been studied. In the strong coupling situations, the system behaves as a single thin film with effective cubic and uniaxial anisotropy fields. The variation of the torque curve slope with the coupling strength has been studied. When the coupling is antiferromagnetic, a discontinuity in the slope value is observed at a critical coupling value where the `spin-flop’ occurs. This analysis could be used to study experimentally the nature and the strength of the magnetic coupling in a system with cubic and/or uniaxial magnetocrystalline anisotropies.