On magnetic properties and domain structure of strontium ferrite particles

Abstract

SrFe12O19 is used commercially as carrier. Magnetic properties, crystal structure, particle morphology, grain structure, and magnetic domain structure were studied as a function of processing temperature (T). The particle properties were found to depend critically upon T. Excessively low T (e.g., 1000 °C) yields an incomplete reaction, with poor magnetics and impurity phases. Excessively high T (e.g., 1350 °C) alters the structure and is detrimental to the magnetic properties. Within the acceptable temperature range, low T produces fine grain and submicron magnetic domains, whereas high T produces coarse grain and a micron-size domain structure.