Determination of magnetic coupling from torque curve

Torque relations have been derived as a function of the coupling strength f or an interfacially coupled two-layer magnetic system. The two layers are c onsidered to be single crystal thin films characterized by uniaxial and cub ic magnetocrystalline anisotropies. Both ferromagnetic and antiferromagneti c coupling cases have been studied. In the strong coupling situations, the system behaves as a single thin him with effective cubic and uniaxial aniso tropy fields. The variation of the torque curve slope with the coupling str ength has been studied. When the coupling is antiferromagnetic, a discontin uity 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 an d/or uniaxial magnetocrystalline anisotropies. (C) 1999 Elsevier Science B. V. All rights reserved.