Dependence of sensitivity on granulometry in conductimetry g′-Bi2MoO6 sensors

the sensitivity to ethanol, in o2/n2 carrier gas, of g′-bi2moo6 sintered pellets of 10 mm average grain size, is compared with that of thin films, obtained by thermal oxidation of magnetron sputtered, stoichiometrically layered bi-mo deposits, with an average grain size of 0.5 mm. pellet response to a 1.3 % w/w ethanol stimulus, at 500 °c, is 47 %, quantitatively accounted by an increase in ionic conductivity, as evaluated by impedance spectroscopy. this response is totally absent in thin films, under the same conditions, due the increase in electronic and surface conductions.