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.