SINTERING STUDIES OF HYDROTHERMAL NIZN FERRITES

The isothermal sintering behavior of submicrometer-sized (<50 nm) powd ers of Ni0.38Zn0.53Fe2.09O4, prepared by hydrothermal process, was inv estigated under different sintering conditions. The powders were chara cterized by chemical analysis, energy-dispersive spectrometry (EDS), X -ray powder diffraction and scanning electron microscopy. The powders were compacted uniaxially with polyvinylalcohol and sintered at differ ent times and temperatures, under constant heating and cooling rates. The characterization of the ceramic bodies was conducted by X-ray diff raction, optical and scanning electron microscopy, helium picnometry a nd EDS. The investigations showed high density ferrites with different porosity and microstructures depending on the sintering conditions. T he results have been explained in terms of a qualitative model, which indicates the relative influence of the densification and grain growth rates. (C) 1997 Elsevier Science Ltd.