EFFECT OF DEFECT STRUCTURE ON GAS SENSITIVITY OF LACRO3

The isopropyl alcohol gas sensitivity of LaCrO3 at 250 degrees C is fo und to depend on the amount of TiO2 content and cation stoichiometric ratio of the sample. The gas sensitivity enhancement is related to the defect structure and electrical conduction behavior of p-type, donor- doped semiconductive oxides. The high resistivity coupled with the inc reasing point defects by the donor dopants are responsible for the hig h gas sensitivity of TiO2 doped LaCrO3. It is believed that the positi vely charged ionic-type defects created by dopants act as trapping sit es to adsorb oxygen.