Microstructural evolution of fast-fired nickel–zinc ferrites from hydrothermal nanopowders

Nanocrystalline nickel–zinc ferrites were produced by hydrothermal processing. The powders were submitted to a rapid sintering method (fast-firing) in a wide range of temperatures (1100–1450°C), times (5–240 min), and heating/cooling rates (100, 250, and 400°C/min). The results showed that different microstructures are obtained under these fast-firing conditions. Their effects on the microstructural evolution are discussed in terms of a qualitative model, which indicated the relative predominance of the densification and grain growth rates.