GAS-SENSING CHARACTERISTICS OF YBA2CU3O6+Y

Gas-sensing characteristics of YBa2Cu3O6+y (YBCO) and related compounds that have oxygen-deficient triperovskite structure are investigated. These compounds with small y values, obtained by quenching into liquid N2 from 950-degrees-C or annealing in N2 at 600-degrees-C, are semiconductors and change their resistance under contact with NO and NO2. The largest and fastest resistance changes in the YBCO compounds in contact with NO take place at rather low operating temperatures, 150-200-degrees-C. From the data involving the effect on the sensitivity of the substitution of each component element or of additives, it is concluded that Cu, whose coordination number with oxygen is nearly two, plays a crucial role in the sensitivity to nitrogen oxide.