Densification and magnetic properties of low-fire NiCuZn ferrites

The mixing of (Ni0.38Cu0.12Zn0.50)Fe2O4 powders with Bi2O3 was performed us ing the solid-state mixing as well as wet chemical coating processes such a s ammonia precipitation coating, urea precipitation coating, and solution c oating. Ferrites prepared from the wet chemical coating processes could be densified at a lower sintering temperature without significant impact on th e microstructural evolution compared with that prepared by solid-state mixi ng. In addition, samples prepared from the wet chemical coating process hav e a higher B-r and B-s and a lower H-c compared with that from solid-state mixing. Considering both the effects of sintering temperature and sintered density (> 95% T.D.), ferrites with 1.5wt% Bi2O3 addition by ammonia precip itation coating sintered at 900 degrees C can provide the best permeability and quality factor (191 and 68.2, respectively) among all the cases studie d. (C) 2000 Elsevier Science B.V. All rights reserved.