Thick film hydrogen sensor based on nanocrystalline nickel ferrite prepared using simple microwave oven

This paper reports the synthesis of nano crystalline nickel ferrite (NiFe₂O₄) by solvothermal technique using simple microwave oven. This ferrite nano powder was used as a functional material in the thick film sensors. Thick film sensors were fabricated using screen printing technique. The structural, microstructural, thermal analysis of powder and the film were characterized by XRD, SEM and TG analysis. The hydrogen sensing properties of the sensor was detected by measuring the change in resistance under the exposure of gas. The results show that nickel ferrite provides good sensitivity nd response to H₂ gas at an operating temperature of 175°C.