FAST OXYGEN SENSORS BASED ON SPUTTERED STRONTIUM-TITANATE

The preparation of oxygen sensors based on sputtered strontium titanate films is described. Like bulk materials, the thin films show p-type and n-type conductivity which depends on the oxygen partial pressure. Using mixtures of argon and oxygen at 950-degrees-C, response times lower than 5 ms can be detected due to a change in the oxygen partial pressure. Because the temperature in an exhaust gas reaches its maximum value at lambda = 1, fast gas and lower temperature effects on the sensor signal of La-doped SrTiO3 can be separated.