Synthesis and Pressure Sensing Properties of the Pristine Cobalt Oxide Nanopowder

During this study the pressure sensing properties of pristine Co3O4 nanopowder has been investigated. A transducer has been fabricated for the direct measurement of effect of pressure on impedance, capacitance and resistance of pristine nanopowders. On increasing pressure from 0 to 8.15 kN/m2 the impedance and resistance of the samples reduces by 27% (on average) in the frequency range of 100 Hz to 200 kHz, while the capacitance increases by 58% at 100 Hz). It is also observed that the impedance of the samples decreases with increase in frequency. This behavior can be attributed to the densification of samples under the effect of pressure which intern reduces the porosity. Moreover, under the applied pressure the resistance (DC) initially rises with time and then saturates with-in 2-3 minutes. This phenomenon may be regarded to the effect of currents of bound charges (displacement current), including ions. The resistance- pressure relationship has also been simulated and the results found in good agreement with experimental data.