Phase transition performance recovery of W-doped VO2 by annealing treatment

W-doped monoclinic VO2 nanoparticles were synthesized using a hydrothermal method. The phase transition temperature of these nanoparticles was lowered to approximately 26 degrees C when doped with 2 at% W. The temperature reduction efficiency was found to be-22 degrees C/at% W. An annealing process was used to improve phase transition performance of doped VO2 samples. The latent heat of the phase transition for the doped VO2 sample increased at higher annealing temperatures, and it was comparable to that of undoped VO2 when annealed at 950 degrees C. This work showed that the phase transition performance of doped VO2 was improved following annealing and the phase transition temperature could remain relatively low. Additionally, annealing was found to eliminate the amorphous VO2 coating that surrounded the VO2 particles and enhance the crystallinity of doped VO2, which led to the recovery of the transition performance of W-doped VO2.