Comparison of different methods to produce dense zinc ferrite ceramics with high electrical resistance

摘要

Three different methods were used to produce dense ZnFe_2O_4 ceramics with high electrical resistance - spray pyrolysis (SP), conventional sintering (CS) and spark plasma sintering (SPS). The phase purity was determined by X-ray diffraction and the morphology/particle size investigated by scanning electron microscopy. It was found that SP is the most appropriate method to produce a dense ZnFe_2O_4 ceramics with high electrical resistivity. By using the SP method, about 500 nm thick ZnFe_2O_4 films were obtained possessing a resistivity with 7 orders of magnitude higher than resistivity of ZnFe_2O_4 pellet sintered by SPS. Both samples obtained by SP and SPS show density close to the theoretical value. The sample obtained by CS shows a low resistivity and relatively high porosity.