A COMPARISON BETWEEN DIFFERENT METHODS FOR EVALUATING THE PARTICLE INTERACTIONS IN MAGNETIC RECORDING-SYSTEMS

Two different methods for the determination of the magnetic interparti cle interactions in recording systems are compared. The first one is t hat based on the evaluation of the deviation Delta m from the Wohlfart h equation for noninteracting particles which requires the measurement of the remanence curves. The other is an easier procedure which consi sts in the determination of the deviation Delta m from an equation ba sed on the initial magnetization curve and the hysteresis loop. For sy stems of oriented uniaxial anisotropy particles is generally Delta m c ongruent to 2 Delta m, while for systems of oriented multiaxial parti cles or for random oriented particles is Delta m 4 Delta m. The advan tage of the second method is its applicability on systems where the in itial curve and the hysteresis loop must be corrected by the demagneti zing field as for CoCr films magnetized perpendicularly to the film pl ane.