Sintering behaviour and microstructures of nanostructured ZnO–ZnS core–shell powder by spark plasma sintering

Densification of nanostructured ZnO–ZnS core–shell powder was carried out by spark plasma sintering to produce a bulk ZnO–ZnS composite. By adjusting the sintering temperature, we could fabricate a bulk ZnO–ZnS composite without destroying the original core–shell structure of the powder. X-ray diffraction and transmission electron microscopy were used to characterize the microstructural properties of the core–shell powder and its sintering behaviour. During spark plasma sintering, phase transition from a sphalerite to a wurtzite structure was observed in the ZnS shell and the crystallographic orientation of the ZnS shell was affected by the ZnO core.