The preparation and phase transformation characteristics of γ-Ti₃O₅ thin film

The high purity γ-Ti₃O₅ thin films deposited on single-crystal SiO₂ substrates are firstly prepared via sol–gel method combined with hydrogen reduction processing. In this reported work, the influences of reduction of temperature, hydrogen flow rate and holding time on the reduced phases are investigated. The as-prepared materials are characterized by glancing incident angle X-ray diffraction, scanning electron microscopy. Based on the results of single factor and orthogonal tests, the optimum condition for synthesizing high purity Ti₃O₅ thin films are as follows: the hydrogen gas flow rate is 0.8 L min⁻¹, the reduction temperature is 1150 °C and the holding time is 1 h. Temperature dependence of PXRD patterns and electrical conductivity (σ) variation demonstrates that the temperature of phase transition between monoclinic I2/c crystal structure of γ-Ti₃O₅ thin film and monoclinic P2/a crystal structure of δ-Ti₃O₅ thin film was 225 K. The four-point probe test shows that the room-temperature conductivity of γ-Ti₃O₅ thin film is 202.1 S m⁻¹.