Negative pressure effects in SrTiO3 nanoparticles investigated by Raman spectroscopy

Wu, Xiaoqiang; Wu, Da‐Jian; Liu, Xiaojun

doi:10.1016/j.ssc.2007.11.018

Cited by 49 publications

(50 citation statements)

References 26 publications

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“…However, the properties of STO are dependent on its chemical composition as well as its structure, shape and size [13,14]. Other important characteristics of these materials include the partial substitution of the cations at both the A and B sites of ABO 3 and the ability to maintain the stability of unusual mixed oxidation states in the crystal structure.…”

Section: Introductionmentioning

confidence: 99%

Structural characterisation of slightly Fe-doped SrTiO3 grown via a sol–gel hydrothermal synthesis

Fuentes

Muñoz

Barraza

et al. 2015

J Sol-Gel Sci Technol

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A detailed structural study of the incorporation of Fe into SrTiO 3 nanoparticles is reported. Slightly irondoped strontium titanate nanoparticles with 0, 1, 3 and 5 mol% concentration of iron were grown using a sol-gel hydrothermal process and characterised using Raman scattering, X-ray photoelectron and X-ray diffraction spectroscopy. The amorphisation of the nanostructures was observed as the iron content increased, which was confirmed by the TEM images. The XPS results indicated that the oxidation states of the Sr atoms were maintained in 2?. However, a mixture of Fe 3? and Fe 4? atoms was observed as the Fe content increased, resulting in a significant number of oxygen vacancies in the perovskite structure. The analysis of Raman spectra indicated that the intensity, linewidth and frequency shift of the TO 4 phonon can be used as an indicator of the Fe content as well as a local temperature probe for future thermal analysis. Graphical abstract Temperature evolution of the Raman spectra of STO:Fe 1 mol%. The peaks with star correspond to the second-order processes. (b) Temperature dependence of the TO 4 phonon mode. Blue dots denote measured Raman spectra, and the red solid lines are the Lorentzian fits to respective spectra.

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Section: Introductionmentioning

confidence: 99%

Structural characterisation of slightly Fe-doped SrTiO3 grown via a sol–gel hydrothermal synthesis

Fuentes

Muñoz

Barraza

et al. 2015

J Sol-Gel Sci Technol

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“…SrTiO 3 is a typical perovskite-structured oxide with a large bandgap of 3.2 eV [7,8,9], which can have its chemical and electrical properties tuned either by doping or by controlling the number of oxygen vacancies [10,11]. It is well known that the properties of SrTiO 3 nanoparticles strongly depend on their morphology, structure, chemical composition, and crystallinity [12,13]. The development of new synthesis techniques and structures for SrTiO 3 materials is essential in view of their practical applications.…”

Section: Introductionmentioning

confidence: 99%

Rapid Synthesis and Formation Mechanism of Core-Shell-Structured La-Doped SrTiO3 with a Nb-Doped Shell

et al. 2015

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To provide a convenient and practical synthesis process for metal ion doping on the surface of nanoparticles in an assembled nanostructure, core-shell-structured La-doped SrTiO3 nanocubes with a Nb-doped surface layer were synthesized via a rapid synthesis combining a rapid sol-precipitation and hydrothermal process. The La-doped SrTiO3 nanocubes were formed at room temperature by a rapid dissolution of NaOH pellets during the rapid sol-precipitation process, and the Nb-doped surface (shell) along with Nb-rich edges formed on the core nanocubes via the hydrothermal process. The formation mechanism of the core-shell-structured nanocubes and their shape evolution as a function of the Nb doping level were investigated. The synthesized core-shell-structured nanocubes could be arranged face-to-face on a SiO2/Si substrate by a slow evaporation process, and this nanostructured 10 μm thick thin film showed a smooth surface.

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“…cle and coherent domain size decrease, that can be tentatively connected to negative pressure effect [5,6], which becomes much stronger for particle size less than 10 nm (Fig. 2).…”

Section: Resultsmentioning

confidence: 83%

“…So does BaTiO 3 , where it is related to the change in Ti-O bonding character [4]. For SrTiO 3 the lattice expansion with size decrease in the range of 12-80 nm has been reported in [5,6] and was connected to negative pressure caused by surface-defect dipole repulsion. Strong increase of the band gap magnitude E g in SrTiO 3 nanoparticles has been also observed in [5].…”

Section: +mentioning

confidence: 96%

Size Effect on the Structure and Optical Properties in Nanocrystalline SrTiO<sub>3</sub>

Makarova

Drahokoupil

Bykov

et al. 2012

e-J. Surf. Sci. Nanotechnol.

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SrTiO3 nanoparticles can be prospective materials for different physical, chemical and technical applications as dielectric components, materials for catalysis and optics. Particle control may lead to new effects especially when the size becomes comparable with the fundamental dimensional characteristics such as domain size, exciton or electron length, i.e. at the level of nanomaterials. The powders of titanate with perovskite structure and particle size of 5-60 nm were obtained by solvothermal or citrate sol gel methods. The tendency to the lattice constant increase with particle size decrease was observed. However, the dependence of optical gap on the particle size looked unusually which was connected with the structure modifications during sample processing. It was also observed that the finest 5 nm powders contained significant lack of Sr, but perovskite structure was preserved. After thermal treatment TiO2 formation was found, likely providing a composite with ultrafine SrTiO3 nanoparticles inside TiO2 shell.

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Negative pressure effects in SrTiO3 nanoparticles investigated by Raman spectroscopy

Cited by 49 publications

References 26 publications

Structural characterisation of slightly Fe-doped SrTiO3 grown via a sol–gel hydrothermal synthesis

Structural characterisation of slightly Fe-doped SrTiO3 grown via a sol–gel hydrothermal synthesis

Rapid Synthesis and Formation Mechanism of Core-Shell-Structured La-Doped SrTiO3 with a Nb-Doped Shell

Size Effect on the Structure and Optical Properties in Nanocrystalline SrTiO<sub>3</sub>

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