A two-step synthesis of NiZn–W hexaferrites

We have investigated the formation of single-phase NiZn–W hexaferrites using two different approaches to the synthesis: a direct synthesis from an initial reagent mixture and a two-step synthesis from intermediates. As calculated, the probability of forming single-phase powders with a direct synthesis was lower than for the two-step synthesis. Powders were synthesized with both approaches via coprecipitation followed by a calcination at 1200–1300 °C. The synthesis was monitored with X-ray powder diffraction, thermogravimetric and thermomagnetic analyses. Single-phase NiZn–W hexaferrite powders were only obtained with the two-step synthesis. The electromagnetic properties of the NiZn–W powders and ceramics were measured.