Correlation between crystallite sizes and microstrains in TiO2 nanopowders

Depero, Laura E.; Sangaletti, L.; Allieri, Brigida; Bontempi, Elza; Marino, Alessandra; Zocchi, M.

doi:10.1016/s0022-0248(98)01086-0

Cited by 42 publications

(29 citation statements)

References 22 publications

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“…It is therefore possible that the mechanism of critical titania particle size, similar to the one proposed by Reidy et al [24], is also in play during SHVOF process. As for microstrains, their larger values in anatase as compared with rutile bear similarities to the findings in titania nanopowders, in which anatase is expected to have larger microstrains [51].…”

Section: Anatase To Rutile Transformation During Shvofsupporting

confidence: 67%

Suspension high velocity oxy-fuel spraying of TiO 2 : A quantitative approach to phase composition

Pala

Shaw

Murray

et al. 2017

Journal of the European Ceramic Society

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A range of coatings from water suspension of anatase has been prepared by suspension high velocity oxy-fuel spraying with the aim to study effects of heat power of the flame on phase composition, microstructure and surface topography. Three most commonly used approaches of quantitative phase analysis have been scrutinized with respect to their applicability and as some of the coatings showed presence of preferred orientation it was argued that quantitative Rietveld refinement is the most accurate method for phase composition determination. Coatings had a layered duplex anatase/rutile microstructure with fraction of rutile increasing exponentially with heat power. Spraying at the lower heat power led to a lower surface roughness and higher power resulted in surfaces with pronounced humps, which were distributed homogeneously on the surface. The emergence of humps is related to an increase in macroscopic surface area of up to 30 % with respect to the flat coating.

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Section: Anatase To Rutile Transformation During Shvofsupporting

confidence: 67%

Suspension high velocity oxy-fuel spraying of TiO 2 : A quantitative approach to phase composition

Pala

Shaw

Murray

et al. 2017

Journal of the European Ceramic Society

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“…Depero et al 13 working with X-TiO 2 systems, where X=Al, Ga, Nb and Ta, observed a linear correlation between <" 2 > 1/2 (microstrain) and 1/ < d> , where < d> is the average crystallite size. They showed, for rutile phase, the existence of a straight line passing by the origin.…”

Section: Resultsmentioning

confidence: 99%

Microstructural and morphological analysis of pure and Ce-doped tin dioxide nanoparticles

Maciel

Lisboa‐Filho

Leite

et al. 2003

Journal of the European Ceramic Society

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Structural and morphological studies in pure and Ce-doped tin dioxide nanoparticles with high stability against particle growth were performed in samples, obtained using the polymeric precursor method and prepared at different annealing temperatures. A Ce-rich surface layer was used to control the particle size and stabilize SnO 2 against particle growth. The formation of this segregated layer can contribute to a decreased surface energy, acting in the driving force, or reducing the surface mobility. Only the cassiterite SnO 2 phase was observed below 1000 C and a secondary phase (CeO 2 ) was observed for the Ce-doped SnO 2 at temperatures higher than 1000 C, when de-mixing process occurs. The evolution of crystallite size, microstrain and morphology of the nanoparticles with annealing temperatures was investigated by X-ray diffraction (XRD), associated to Rietveld refinements, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). #

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“…In general terms, the grain growth hindering observed when our samples were loaded with Nb was very similar to that found by other authors. 20,42 The Nb 5ϩ radius ͑0.70 Å͒ is slightly bigger than the Ti 4ϩ radius ͑0.68 Å͒ and this means that Nb 5ϩ induces slight stress in titania lattice, which may hinder the growth of the TiO 2 crystallites, as was found by Sharma and Bhatnagar. 20 Moreover, we also found that TiO 2 anatase particles were smaller than rutile ones in the same sample.…”

Section: Grain Growth Inhibitionmentioning

confidence: 86%

Effects of Nb doping on the TiO2 anatase-to-rutile phase transition

Arbiol

Cerdá

Dezanneau

et al. 2002

Journal of Applied Physics

313

184

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We study the influence of Nb doping on the TiO 2 anatase-to-rutile phase transition, using combined transmission electron microscopy, Raman spectroscopy, x-ray diffraction and selected area electron diffraction analysis. This approach enabled anatase-to-rutile phase transition hindering to be clearly observed for low Nb-doped TiO 2 samples. Moreover, there was clear grain growth inhibition in the samples containing Nb. The use of high resolution transmission electron microscopy with our samples provides an innovative perspective compared with previous research on this issue. Our analysis shows that niobium is segregated from the anatase structure before and during the phase transformation, leading to the formation of NbO nanoclusters on the surface of the TiO 2 rutile nanoparticles.

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Correlation between crystallite sizes and microstrains in TiO2 nanopowders

Cited by 42 publications

References 22 publications

Suspension high velocity oxy-fuel spraying of TiO 2 : A quantitative approach to phase composition

Suspension high velocity oxy-fuel spraying of TiO 2 : A quantitative approach to phase composition

Microstructural and morphological analysis of pure and Ce-doped tin dioxide nanoparticles

Effects of Nb doping on the TiO2 anatase-to-rutile phase transition

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