Influence of the Preparation Technique on the Resistance of the PbSe +PbSeO_3 Two-Phase Composite

摘要

An anomalous change in the electrical conductivity near the phase transition temperature (343 K)is revealed in a PbSe +PbSeO_3 two-phase polycrystalline composite.It is demonstrated that the observed effect can be used in the design of chemical gas sensors,in which the chemisorption of a reducing or oxidizing gas on the surface of the PbSe +PbSeO_3 composite should lead to a significant change in the electrical conductivity at temperatures close to the phase transition point.The PbSe +PbSeO_3 composite is studied by impedance spec-troscopy in the temperature range 293-393 K in a dry air atmosphere.It is found that the interaction of the sample with air oxygen under the controlled joint action of an ac electric field and heat can lead to both reversible and irreversible changes in the electrical conductivity.