Thermal hysteresis control of VO2 (M) nanoparticles by Ti-F codoping

Abstract We have synthesized F-doped Ti x V 1−x O2 nanoparticles by hydrothermal method and examined the structural phase transition behavior depending on the Ti and F contents. Differential scanning calorimetry and temperature-dependent X-ray diffraction analyses revealed that, by the codoping of Ti and F in VO2, both the critical phase transition temperature (Tc) and the thermal hysteresis width ( Δ T c ) are appropriately reduced. We have also examined the thermochromic behavior for the composite films prepared by casting F-doped Ti x V 1−x O2 nanoparticles. The 2.0% F-doped Ti 0.08 V 0.92 O2 composite film exhibited a decreased Tc of approximately 20 °C and narrow Δ T c of below 2 °C. This result clearly shows the potential of F-doped Ti x V 1−x O2 nanoparticles for sensitive optical device application.