Crystal Structure, Phase, and Electrical Conductivity of Nanocrystalline W0.95Ti0.05O3 Thin Films

W0.95Ti0.05O3 films were fabricated using sputter-deposition onto Si(100) wafers in by varying the growth temperature from room temperature (RT) to 500 degrees C. X-ray diffraction (XRD), high-resolution scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDS), and Raman spectroscopy (RS) were performed to investigate the effect of temperature on the growth behavior, crystal structure, texturing, surface morphology, and chemical bonding of W0.95Ti0.5O3 films. The results indicate that the effect of temperature is significant on the growth and microstructure of W0.95Ti0.05O3 films. XRD results indicate that the effect of Ti is remarkable on the crystallization of WO3. W0.95Ti0.05O3 films grown at temperatures <300 degrees C are amorphous compared to pure WO3 crystalline films crystallizing at 200 degrees C. Phase transformation is induced in W0.95Ti0.05O3 resulting in tetragonal structure at >= 300 degrees C. The structural changes were also reflected in the intensities of -W-O-W- vibrational modes in RS measurements. The SEM imaging analysis indicates that the phase transformations are accompanied by a characteristic change in surface morphology. Room temperature electrical conductivity of W0.95Ti0.05O3 films increases from 0.63 to 27 (Omega m)(-1) with increasing temperature from RT to 400 degrees C due to improved structural order. Electrical conductivity exhibit a decrease at 500 degrees C (7.4 (Omega m)(-1)) due to disordering induced by Ti segregation, which is confirmed by XRD and RS measurements.