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The present work shows the improved humidity sensing characteristics of TiO2 nanoparticles in the form of a nanocomposite with multiwalled carbon nanotubes (MWCNTs) prepared by a hydration–dehydration method. The structural and morphological characterizations of TiO2–MWCNTs confirm the nanocomposite formation without any other impurities and with an improved surface area. The pure TiO2 and nanocomposite films are deposited on IDE coated flexible poly-ethylene terephthalate (PET) substrates by a drop casting method. The nanocomposite shows improved sensitivity (1246.2 MΩ/%RH) and an ultrafast response/recovery time (2 s/1 s) with a minimal hysteresis of 0.27%RH. Further, the flexible nanocomposite sensor is tested for human healthcare applications including respiratory monitoring, apnea like situations, and skin moisture detection. The sensor can distinguish different breath patterns like normal, fast, deep and apnea like situations significantly. Skin moisture detection can also be performed using the nanocomposite sensor in a non-invasive manner. Overall, this study represents an environmentally friendly, easy to fabricate, flexible TiO2–MWCNT nanocomposite based improved humidity sensor for application in human healthcare and wearable devices. [ABSTRACT FROM AUTHOR]

We study the structural and electronic properties of Fe doped (4-8 at. %) and undoped TiO2 thin films deposited by pulsed laser deposition on Si(111) substrate. The films grow in single phase anatase structure of TiO2 as revealed by x-ray diffraction and Raman spectroscopy measurements. The Fe doped films reveal room temperature magnetic hysteresis behavior. We have probed the electronic environment of Fe in TiO2 matrix and its coupling to the cations, using photoelectron spectroscopy measurements. Photoelectron spectroscopic studies reveal the ionic state of Fe in TiO2, precluding the formation of Fe metal clusters. Valence band spectra of these films suggest that it primarily consists of O-2p derived state, however, Fe derived state is also observed in Fe doped films. Resonance photoelectron spectroscopy studies indicate that Fe ions are hybridized with Ti3+ defect states. [ABSTRACT FROM AUTHOR]

The electronic structure of CeO2 thin film grown by pulsed laser deposition on Si (100) substrate has been investigated using resonance photoemission spectroscopy (RPES). X-ray photoemission study on the film suggests that Ce has 3+ and 4+ valence states. Valence band spectra of the film show a feature at 2.1 eV of binding energy and a broad band at higher binding energy due to O 2p derived state. RPES measurements performed in the Ce 4d→4f photoabsorption region show maximum intensity for 2.1 eV feature at photon energy of 122 eV confirming it to be due to Ce3+ (4f1) state. RPES measurements also show maximum intensity for binding energy position of 4.4 eV in the broad band at photon energy of 125 eV, suggesting it to be due to Ce4+ (4f0) state. Constant initial state (CIS) versus photon energy plots also confirm these findings and suggest that the broad band is admixture of O 2p and Ce 4f and 5d derived states. [ABSTRACT FROM AUTHOR]

The resonance photoemission spectroscopy (RPES) technique is employed to explain the electronic structure of the Ce[O.sub.2] thin film grown on Si (100) substrate by pulsed laser deposition technique. The valence band spectra of the film is shown to exhibit a binding energy of 2.1 eV.

We have studied the spin-dependent electron momentum density distribution in CoGaFeO ( x = 0.2, 0.3) at a low temperature (8 K) using magnetic Compton scattering technique. Further, the effect of Ga doping on the electronic structure is studied using X-ray photoemission spectroscopy (XPS). It is revealed that doping of Ga substitutes the Fe ions predominantly at tetrahedral (P) site, which promotes a gradual immigration of small amount of Co ions from tetrahedral to octahedral (Q) site. Total spin moment increases remarkably on increasing the doping concentration of nonmagnetic Ga ( x = 0 → 0.3) in the base cobalt ferrite. It is seen that major contribution to total spin moment mainly arises from Co ions while itinerant electrons show negative polarization. On Ga doping, spin moment at Fe site increases dramatically with a minor increment at Co site. The increased spin moment is attributed to the increased Q/P occupancy ratio of Fe as well as Co ions as determined using XPS measurements. In contrast, orbital moment does not show such deviations, suggesting that a small amount of Ga doping can enhance the magnetization significantly, without inducing any significant distortion to modify the spin-orbit coupling. [ABSTRACT FROM AUTHOR]