Static and dynamic switching field distribution for magnetic tape systems

A low temperature (77K-300K) axial vibrating sample magnetometer, in which a specimen may be subjected to both AC and DC fields simultaneously, has been used to determine the static and dynamic magnetic properties of a professional quality γ-Fe2O3audio recording tape. The differential of the IRM curve was used to determine the switching field distribution (SFD) of the system. SFD´s calculated in this way were compared with the equivalent parameters determined from AC melting curves. A significant difference was found which has been attributed to interparticle interactions.