Effect of solid contents on the electrical properties of Co2.77Mn1.71Fe1.10Zn0.42O8 ceramic prepared by slurry spin coating technique

Abstract

A series of negative temperature coefficient (NTC) thick-film ceramics based on Co2.77Mn1.71Fe1.10Zn0.42O8 (CMFZ) were successful prepared using a slurry spin coating technique. The high density and stable B25/50 constant in the range of 3829–3862 K of CMFZ thick films were obtained. The feasibility of preparing CMFZ thick films by spin coating is proved. It is confirmed that the microstructure and electrical properties of films are sensitive to the solid content in pastes. A smoother and denser surface morphology and relatively high electrical stability is obtained in 70 wt% solid content with the resistance drift rate of 19.4%. The resistance drift rate of all samples is found to be less than 1% per 100 h after pre-aging at 125 °C for 400 h. Compared to the traditional screen-printing method, spin coating simplifies the process steps and reduces some variables that could affect the quality of the thick film. These results clearly indicate that the spin coating technique is a potential and competitive method in the production of NTC thick film ceramic.