Hopkinson effect and temperature-dependent dielectric properties of single domain SrFe12O19 particles

Strontium hexagonal ferrite particles having single domain nature were prepared by initial ball milling followed by sintering. Effect of the synthesis method on structural, magnetic, and electrical properties were analyzed using various characterization techniques. XRD pattern reveals the formation of hexagonal phase SrFe12O19. XPS study indicates the presence of Fe3+ in different crystallographic environments. SEM image suggests the size of particles in the range of single domain. VSM studies; M-H loop illustrates the ferrimagnetic nature and the initial magnetization behavior demonstrates the typical behavior of single domain particles. Temperature-dependent magnetization shows a Hopkinson peak before transition. Conductivity study shows two different conduction process with the activation energy values of 0.2 and 0.95eV. The variation in the dielectric behavior with respect to frequency and temperature are explained using the grain-grain boundary and polarization contributions. The hard ferrimagnetism and good dielectric response renders this material suitable for magneto-electronic devices.