Doping directed metal oxidation

At the heart of the sensor is a slab of doped transition-metal oxide. Its mode of operation is to detect the concentration of CO within the oxide slab, which is in direct proportion to the concentration of CO gas in the air surrounding it, according to Henry s law. 

In doped semiconductors I is due to direct overlap in transitional-metal oxides the overlap between the d-orbitals is frequentiy via the oxygen ions and is then often called a superexchange interaction. Figure 3.4 shows the kinds of wave function expected. As regards magnitudes, if B 1 eV, 17 10 eV and z=4, kBTN should be 0.01 eV so that 100K, which shows why low Neel temperatures are common. 

R ently, the use of oxidized PANI has been r ognized as an inter ting means of protecting oxidizable metals. Debeny (I) was the first to show that a PANI film coated on stainless steel by electrochemical oxidation of aniline acted as a protective primer. This protection has been explained by a redox effect of the doped PANI, which maintains the metallic oxide film in its passive state. These result were confirmed by MacDiarmid et al. (2) and later, Wessling et al. (3) showed that chromating could be replaced by the direct deposition of a PANI dispersion on the metal. 

---