The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform

Takeshi Matsuda - One of the best experts on this subject based on the ideXlab platform.

  • control of the Quantum Size Effect of tio2 sio2 hybrid particles
    Materials Letters, 2009
    Co-Authors: Tomoya Ohno, Kazunori Numakura, Hidenobu Itoh, Hisao Suzuki, Takeshi Matsuda
    Abstract:

    Abstract This paper describes the control of the Quantum Size Effect by controlling the coating layer thickness in TiO 2 –SiO 2 core-shell hybrid particles obtained by the liquid phase deposition (LPD) method. The coating layer thickness of TiO 2 on SiO 2 nano-particles was controlled by changing the [Ti]/[Si] ratio. The titania coating thickness and crystallite Size were estimated by transmission electron microscope (TEM) and X-ray diffraction (XRD), respectively. The Quantum Size Effect of the obtained nano-hybrid particles was estimated by the band gap energy shift, using ultraviolet-visible spectroscopy (UV–vis). As a result, we successfully controlled the degree of the Quantum Size Effect by controlling the coating layer thickness in core-shell TiO 2 –SiO 2 hybrid particles.

  • Control of the Quantum Size Effect of TiO2–SiO2 hybrid particles
    Materials Letters, 2009
    Co-Authors: Tomoya Ohno, Kazunori Numakura, Hidenobu Itoh, Hisao Suzuki, Takeshi Matsuda
    Abstract:

    Abstract This paper describes the control of the Quantum Size Effect by controlling the coating layer thickness in TiO 2 –SiO 2 core-shell hybrid particles obtained by the liquid phase deposition (LPD) method. The coating layer thickness of TiO 2 on SiO 2 nano-particles was controlled by changing the [Ti]/[Si] ratio. The titania coating thickness and crystallite Size were estimated by transmission electron microscope (TEM) and X-ray diffraction (XRD), respectively. The Quantum Size Effect of the obtained nano-hybrid particles was estimated by the band gap energy shift, using ultraviolet-visible spectroscopy (UV–vis). As a result, we successfully controlled the degree of the Quantum Size Effect by controlling the coating layer thickness in core-shell TiO 2 –SiO 2 hybrid particles.

Lin Tang - One of the best experts on this subject based on the ideXlab platform.

  • interplay between Quantum Size Effect and strain Effect on growth of nanoscale metal thin films
    Physical Review B, 2012
    Co-Authors: Lin Tang
    Abstract:

    We develop a theoretical framework to investigate the interplay between Quantum Size Effect (QSE) and strain Effect on the stability of metal nanofilms. The QSE and strain Effect are shown to be coupled through the concept of "Quantum electronic stress. First-principles calculations reveal large Quantum oscillations in the surface stress of metal nanofilms as a function of film thickness. This adds extrinsically additional strain-coupled Quantum oscillations to surface energy of strained metal nanofilms. Our theory enables a quantitative estimation of the amount of strain in experimental samples, and suggests strain be an important factor contributing to the discrepancies between the existing theories and experiments.

  • Quantum Size Effect on adatom surface diffusion
    Physical Review Letters, 2006
    Co-Authors: Li Ying, Lin Tang, Ze Lei Guan, Ke He, Kang An, Steve Huang
    Abstract:

    Using scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the Quantum Size Effect on surface diffusion. The Fe adatom diffusion barriers were derived to be 204 +/- 5 and 187 +/- 5 meV on a 21 and 26 monolayer (ML) Pb film, respectively, by matching the kinetic Monte Carlo simulations to the experimental island densities. The Effect is further illustrated by the growth of Fe islands on wedged Pb films, where the Fe island density is consistently higher on the odd-layer films than on the even-layer films in the thickness range of 11 to 15 ML.

Tomoya Ohno - One of the best experts on this subject based on the ideXlab platform.

  • control of the Quantum Size Effect of tio2 sio2 hybrid particles
    Materials Letters, 2009
    Co-Authors: Tomoya Ohno, Kazunori Numakura, Hidenobu Itoh, Hisao Suzuki, Takeshi Matsuda
    Abstract:

    Abstract This paper describes the control of the Quantum Size Effect by controlling the coating layer thickness in TiO 2 –SiO 2 core-shell hybrid particles obtained by the liquid phase deposition (LPD) method. The coating layer thickness of TiO 2 on SiO 2 nano-particles was controlled by changing the [Ti]/[Si] ratio. The titania coating thickness and crystallite Size were estimated by transmission electron microscope (TEM) and X-ray diffraction (XRD), respectively. The Quantum Size Effect of the obtained nano-hybrid particles was estimated by the band gap energy shift, using ultraviolet-visible spectroscopy (UV–vis). As a result, we successfully controlled the degree of the Quantum Size Effect by controlling the coating layer thickness in core-shell TiO 2 –SiO 2 hybrid particles.

  • Control of the Quantum Size Effect of TiO2–SiO2 hybrid particles
    Materials Letters, 2009
    Co-Authors: Tomoya Ohno, Kazunori Numakura, Hidenobu Itoh, Hisao Suzuki, Takeshi Matsuda
    Abstract:

    Abstract This paper describes the control of the Quantum Size Effect by controlling the coating layer thickness in TiO 2 –SiO 2 core-shell hybrid particles obtained by the liquid phase deposition (LPD) method. The coating layer thickness of TiO 2 on SiO 2 nano-particles was controlled by changing the [Ti]/[Si] ratio. The titania coating thickness and crystallite Size were estimated by transmission electron microscope (TEM) and X-ray diffraction (XRD), respectively. The Quantum Size Effect of the obtained nano-hybrid particles was estimated by the band gap energy shift, using ultraviolet-visible spectroscopy (UV–vis). As a result, we successfully controlled the degree of the Quantum Size Effect by controlling the coating layer thickness in core-shell TiO 2 –SiO 2 hybrid particles.

Clement Sanchez - One of the best experts on this subject based on the ideXlab platform.

  • Quantum Size Effect in tio2 nanoparticles does it exist
    Applied Surface Science, 2000
    Co-Authors: S Monticone, R Tufeu, A V Kanaev, E Scolan, Clement Sanchez
    Abstract:

    Abstract We have examined the Quantum Size Effect in anatase TiO2 nanoparticles. No shift of the band gap energy has been observed for Sizes 2R≥1.5 nm. On the other hand, we have found unusual variation of the oscillator strength of the first allowed direct transition. The results indicate considerable structural Size Effect, which disables the Effective mass approximation (EMA) in these nanocrystallites.

Tien T Tsong - One of the best experts on this subject based on the ideXlab platform.

  • Quantum Size Effect on ultra thin metallic films
    Journal of Physics D, 2010
    Co-Authors: W B Su, Chiaseng Chang, Tien T Tsong
    Abstract:

    When the thickness of a metallic film is in the nanometre range, electrons in the film as well as those transmitting through the film can both manifest the Quantum Size Effect (QSE). For the former, electrons are confined in the Quantum well of a metal film to form Quantum-well states. For the latter, electrons scattered by the Quantum well in the film can bring about the phenomenon of transmission resonance. Scanning tunnelling microscopy (STM) combined with spectroscopy is a powerful tool to explore these two kinds of QSE. In this paper, we review our recent studies on the QSE of thin Pb and Ag films by using STM. We demonstrate that the formation of the Quantum-well states in the Pb film can significantly affect the morphology, thickness, growth process and electronic structures of Pb films. On the other hand, the transmission resonance can be observed on the Ag film with Z–V spectroscopy in STM. The energy level of the transmission resonance varies with the film thickness and can be shifted by the electric field. Moreover, in the studies of transmission resonance, it is unavoidable to observe the standing-wave states, i.e. Gundlach oscillations, which are the QSE in the tunnelling gap. We have also discovered that the Gundlach oscillation can be exploited to measure the work function of thin metal films with very high precision.