Studies on the Phase Transitions and Properties of Tungsten (VI) Oxide Particles by X-Ray Diffraction (XRD) and Thermal Analysis
Abdullah S.F., and Radiman S., and Abdul Hamid M.A., and Ibrahim N.B., (2007) Studies on the Phase Transitions and Properties of Tungsten (VI) Oxide Particles by X-Ray Diffraction (XRD) and Thermal Analysis. Jurnal Fizik Malaysia, 28 (1 & 2). pp. 7-11. ISSN 0128-0333
Full text not available from this repository.
Universiti Tenaga Nasional. College of Engineering. Dept. of Engineering Science and Mathematics.
University Kebangsaan Malaysia. Faculty Science and Technology. School of Applied Physics.
Tungsten (VI) oxide, WO₃ particles were synthesized by colloidal gas aphrons technique. The resultant WO₃ particles were characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of the WO₃ partic1es. The result from XRD and DTA show that the formation of polymorphs WO₃ particles ,have the following sequence: orthorhombic (β-WO₃)→ monoclinic (γ-WO₃) → triclinic (δ-WO₃) → monoclinic (ε-WO₃ with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the -crystallinity had been obtained by the other samples of the WO₃ particles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ± 5), (50 ± 5), (150 ± 10) and (200 ± 10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO₃ particles is purely anhydrous since the weight loss is insignificant (0.3-1.4)% from 30 until 600°C for the WO₃ particles calcined at 400°C. Finally, the composition and the purity of the WO₃ particles have been examined by X-Ray photoelectron spectroscopy (XPS). The results indicate no significant changes to the composition and the purity of the WO₃ particle produced due to the temperature variations.
Repository Staff Only: item control page