Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing

Nanocrystalline nickel manganite (NiMn2O4) powder with a pure cubic spinel phase structure was synthesized via sol-gel combustion and characterized XRD, FT-IR, XPS SEM. The mixed sodium alginate gel to form nano-biocomposite gel, dried at room temperature thick film FT-IR DC resistance AC impedance of sensor test structures obtained by drop casting the onto interdigitated PdAg electrodes on an alumina substrate were measured in range 20–50 °C constant relative humidity (RH) 50% (25 °C) RH 40–90%. material from decrease determined be 4523 K, while sensitivity −5.09%/K. Analysis complex plots showed dominant influence grains. increase confirmed negative coefficient effect. grain relaxation frequency using equivalent circuit. activation energy for conduction as 0.45 eV dependence according small polaron hopping model, 0.43 Arrhenius temperature.