Raman scattering and lattice defects in nanocrystalline CeO2 thin films

Kosacki, Igor; Suzuki, Toshio; Anderson, Harlan U.; Colomban, Philippe

doi:10.1016/s0167-2738(02)00104-2

Cited by 524 publications

(375 citation statements)

References 19 publications

Supporting

Mentioning

325

Contrasting

Unclassified

Order By: Relevance

“…The defect concentration N = 3/(4π L 0 3 ) is estimated from the mean correlation length L 0 , which corresponds to the diameter of homogeneous sphere, equal to distance between two neighbor oxygen vacancies. [12] From Table 3, it can be seen that powder ZnO-p-30, activated in planetary mill during 30 min, has the smallest correlation length (5.8 nm), with the greatest ratio I(E 1 (LO)/I(E 2 high ) and the highest defect concentration, pointing out to the most disordered structure. In powder ZnO-p-300 activated during 300 min under the same milling condition, the correlation length increases to 7.6 nm, whereas the defect concentration and I(E 1 (LO)/I(E 2 high )) decrease.…”

Section: By Starsmentioning

confidence: 98%

“…The correlation length, which defines the mean size of the homogeneous regions in material, is introduced to describe the crystalline quality. [12] The correlation length, here also denoted by L, is related to the short-range order in material and depends on the defect concentration and nonstoichiometry. In principle, the correlation length may be influenced by the level of disorder due the presence of point defects (vacancies, interstitials), dislocations and voids, as well as the disturbance in long-range order, due to dopant atoms or solid solutions creating.…”

Section: Phonon Confinement and Strain Effects In Raman Spectramentioning

confidence: 99%

“…On the other side, when a B L λ (10 nm < L < 100 nm), the confinement effect is not so relevant, but light scattering is widely influenced by large inner surface, and surface phonon modes appear in Raman spectra between the transversal optical (TO) and longitudinal optical (LO) modes. [5] The phonon confinement model (PCM) has been applied for estimation of ZnO nanocrystal [6,7] and quantum dot [8] dimensions, as well as the correlation length in ZnO thin films [9] and ZnO nanoparticles with Zn substituted by Mn [10] or Co. [11] The effect of phonon confinement due to nanometric correlation length [12] on shift and asymmetric broadening of the E 2 low , [7,11] E 2 high [6 -10] and E 1 (LO) [6] Raman modes in ZnO has also been studied. The PCM has been usually applied in Campbell and Fauchet form.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Raman study of structural disorder in ZnO nanopowders

Šćepanović¹,

Grujić‐Brojčin²,

Vojisavljević³

et al. 2009

J Raman Spectroscopy

386

165

View full text Add to dashboard Cite

Raman scattering spectroscopy has been used for the characterization of zinc oxide nanoparticles obtained by mechanical activation in a high-energy vibro-mill and planetary ball mill. Raman modes observed in spectra of nonactivated sample are assigned to Raman spectra of the ZnO monocrystal, while the spectra of mechanically activated samples point out to the structural and stoichiometric changes, depending on the milling time and the choice of equipment. Observed redshift and peak broadening of the E 2 high and E 1 (LO) first-order Raman modes are attributed to increased disorder induced by mechanical milling, followed by the effects of phonon confinement due to correlation length decrease. The additional modes identified in Raman spectra of activated ZnO samples are related to the surface optical phonon modes, due to the intrinsic surface defects and presence of ZrO 2 as extrinsic defects introduced by milling in zirconia vials.

show abstract

Section: By Starsmentioning

confidence: 98%

Section: Phonon Confinement and Strain Effects In Raman Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Raman study of structural disorder in ZnO nanopowders

Šćepanović¹,

Grujić‐Brojčin²,

Vojisavljević³

et al. 2009

J Raman Spectroscopy

386

165

View full text Add to dashboard Cite

show abstract

“…4), only a very strong confinement is indeed expected to provoke such a significant mode shift in CdS. [51,52] The modelling of Raman selection rule breakdown by the phenomenological spatialconfinementmodel (a decreasing weight exploration of bulk dispersion branches from Brillouin zone centre outwards [21,51,53,54] ) is irrelevant since the wavevectors associated with 298 cm −1 wavenumber are much too far from Brillouin zone centre (Fig. 4).…”

Section: Grinding-induced Transformationsmentioning

confidence: 99%

Off‐resonance Raman analysis of wurtzite CdS ground to the nanoscale: structural and size‐related effects

Gouadec

Colomban

et al. 2011

J Raman Spectroscopy

View full text Add to dashboard Cite

Different techniques were used to follow the transformation of CdS platelets during grinding and under hydrostatic pressure. X-ray diffraction and transmission electron microscopy revealed that the platelets included zinc blende (cubic) CdS nanodomains dispersed in a wurtzite (hexagonal) single-crystalline matrix. Extended grinding led to a decrease of the grain size and to a progressive transformation of the hexagonal stacking into a cubic one. The same phase transition was observed up to 9 GPa under hydrostatic pressure.Off-resonance Raman spectra collected at different stages of the transition led us to connect band groups that were usually overlooked (in resonance conditions) or considered separately. They all probe the stacking disorder and their intensity can be related to the density of stacking faults. Off-resonance Raman spectroscopy offers a way of probing the optical properties of CdS (and, more generally, layered semiconductors) as a function of the structure and of the confinement of vibrations by structural defects.

show abstract

“…[19][20][21][22][23][24] In view of the broad field of applications for zirconia and ceria-based ceramics such as gas sensor materials, [25][26][27][28] electrolyte, and anode materials for microsolid oxide fuel cell membranes, [22,24,[29][30][31][32][33][34] oxygen pumps, and catalytic supports for automotive exhaust [35][36][37] or even biological systems [38] this is problematic. For one metal oxide material the thin film properties vary strongly depending on the ambient state of crystallization and grain growth, and original content of organics and hydroxyl-groups after preparation.…”

Section: Introductionmentioning

confidence: 99%

Crystallization and Grain Growth Kinetics for Precipitation‐Based Ceramics: A Case Study on Amorphous Ceria Thin Films from Spray Pyrolysis

Rupp

Scherrer

Harvey

et al. 2009

Adv Funct Materials

View full text Add to dashboard Cite

The introductory part reviews the impact of thin film fabrication, precipitation versus vacuum‐based methods, on the initial defect state of the material and microstructure evolution to amorphous, biphasic amorphous‐nanocrystalline, and fully nanocrystalline metal oxides. In this study, general rules for the kinetics of nucleation, crystallization, and grain growth of a pure single‐phase metal oxide thin film made by a precipitation‐based technique from a precursor with one single organic solvent are discussed. For this a complete case study on the isothermal and non‐isothermal microstructure evolution of dense amorphous ceria thin films fabricated by spray pyrolysis is conducted. A general model is established and comparison of these thin film microstructure evolution to kinetics of classical glass‐ceramics or metallic glasses is presented. Knowledge on thermal microstructure evolution of originally amorphous precipitation‐based metal oxide thin films allows for their introduction and distinctive microstructure engineering in devices‐based on microelectromechanical (MEMS) technology such as solar cells, capacitors, sensors, micro‐solid oxide fuel cells, or oxygen separation membranes on Si‐chips.

show abstract

Raman scattering and lattice defects in nanocrystalline CeO2 thin films

Cited by 524 publications

References 19 publications

Raman study of structural disorder in ZnO nanopowders

Raman study of structural disorder in ZnO nanopowders

Off‐resonance Raman analysis of wurtzite CdS ground to the nanoscale: structural and size‐related effects

Crystallization and Grain Growth Kinetics for Precipitation‐Based Ceramics: A Case Study on Amorphous Ceria Thin Films from Spray Pyrolysis

Contact Info

Product

Resources

About