Measurement of thermal conductivity of TiO2 thin films using 3ω method

TiO2 film has been used in many industrial components such as laser filters, protection mirrors, chemical sensors, and optical catalysts. Therefore, the thermal properties of TiO2 thin films are important in, e. g., reducing the thermal conductivity of ceramic coatings in gas turbines and increasing the laser damage threshold of antireflection coatings. The thermal conductivity of four kinds of TiO2 thin films, prepared by dc magnetron sputtering, was measured using the 3omega method in the temperature range from 80 K to room temperature. The results showed that the thermal conductivity of TiO2 thin films strongly depends on the thickness and the microstructure of the films. The films with smaller grain size and thinner thickness have smaller thermal conductivities.