Differences in the structural and magnetic properties of nanosized barium hexaferrite powders prepared by single and double microemulsion techniques

Barium hexaferrite powders of nanometer particle size synthesized via two variants of the microemulsion technique, namely, single microemulsion and double microemulsion, were studied. The influence was explored of the type of microemulsion technique on the microstructure and on the magnetic properties of the barium hexaferrite powders. The average particle size of the barium hexaferrite powders was in the range from 110 nm to 442 nm depending on the method and conditions of synthesis. The particles with size below 150 nm had irregular shapes between spherical and platehexagonal; the bigger ones had an almost perfect hexagonal shape. The powders obtained by single microemulsion had better magnetic characteristics (saturation magnetization of 65.12 emu/g and coercivity field of 3.6 × 105 A/m) than those obtained by double microemulsion. © 2013 Elsevier B.V. All rights reserved.