Cu-Mn Co-doped NiFe₂O₄ based thick ceramic film as negative temperature coefficient thermistors

Abstract

NTC (Negative Temperature Coefficient) thermistors are widely used as temperature sensors in industrial and medical applications due to their high-temperature sensitivity, durability, and low cost. Generally, NTC thermistors are made from spinel structured ceramics formed by transition metal oxides with the general formula AB2O4. One of the spinel structured ceramics that can be made for NTC thermistors is NiFe2O4 nanoparticles. This work aimed to prepare Cu-Mn co-doped NiFe2O4 based thick ceramic film using Jarosite mineral as a precursor. The synthesis method used was a simple coprecipitation method, while the technique used in making a thick ceramic film was a simple screen printing technique. The sintering temperatures used were 1000 °C, 1100 °C, and 1200 °C. Based on x-ray diffraction analysis, the thick films consist of spinel phase, hematite phase, and some unidentified phase. The constant thermistor values (B) for thick films obtained with 1000, 1100, and 1200 °C sintering temperatures were 4740 K, 5669 K, and 5731 K, respectively. These results showed that all obtained thick films had passed the minimum value in market needs (B ≥2000 K).

Recovery of Ni-Co-Mn Oxides from End-of-Life Lithium-Ion Batteries for the Application of a Negative Temperature Coefficient Sensor

“…where B is the factor of thermal sensitivity, R is the resistance, k B is the Boltzmann constant, and T is the absolute temperature. Note that the B value defines the relationship between the thermistor's resistance and temperature, which represents the material constant over a specific temperature interval (e.g., between T 1 and T 2 ) [27,28]. Also, a relationship between the resistance and temperature of the (Ni 0.6 Co 0.4 Mn 2 )O 4 pellet can be utilized for temperature sensing applications.…”