Waveguide Raman spectroscopy of TiO2:SiO2 thin films

Bahtat, M.; Mugnier, J.; Bovier, C.; Roux, H.; Serughetti, J.

doi:10.1016/s0022-3093(05)80604-0

Cited by 20 publications

(11 citation statements)

References 11 publications

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“…Actually, the optical properties of the mixed oxides largely depend on their composition, homogeneity, and structure, which are closely related to the preparation method and synthesis condition. In the literature, various techniques have been used to deposit TiO 2 –SiO 2 composite films, such as sol–gel method, electron‐beam coevaporation, ion‐beam sputtering, plasma sputtering, or plasma‐enhanced chemical vapor deposition (PECVD) . Among them, PECVD is attractive for the fabrication of optical waveguides and integrated optical devices.…”

Section: Introductionmentioning

confidence: 99%

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD

Dai

Goullet

et al. 2019

Plasma Processes & Polymers

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TixSi1−xO2 films are grown by plasma‐enhanced chemical vapor deposition from oxygen‐rich O2/titanium tetraisopropoxide/hexamethyldisiloxane radiofrequency inductively coupled plasmas at low pressure. By applying a substrate bias of −50 V, the ion energy is increased from 15 to 75 eV, which has almost no effect on the by‐products, whereas the deposition rate is decreased and the Ti/Si atomic ratio in the film is increased. For the lowest hexamethyldisiloxane fraction in precursor, applying a −50 V bias leads to the formation of TiO2 in rutile phase in the film. The film optical properties (optical index and band gap) are shown to be mainly governed by the film chemical composition.

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Section: Introductionmentioning

confidence: 99%

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD

Dai

Goullet

et al. 2019

Plasma Processes & Polymers

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“…A number of authors have successfully used Raman spectroscopy to successfully characterize sol-gel reaction products [8][9][10][11][12][13][14][15][16][17][18][19][20]. In this study, Raman was used to characterize and investigate the phase morphology of the sol-gel products synthesized in the various gravity conditions.…”

Section: Crystalline Phase Identificationmentioning

confidence: 99%

Synthesis and characterization of titanium sol–gels in varied gravity

Hales¹,

Steinberg²,

Martens³

2014

Journal of Non-Crystalline Solids

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Two unique test systems were designed and built to allow the effects of varied gravity (high, normal, reduced) during synthesis of titanium sol-gels to be studied. A centrifuge capable of providing high gravity environments of up to 70 g for extended periods while applying a 100 mbar vacuum and a temperature of 40-50°C to the reaction chambers was developed. The second system was used in the QUT Microgravity Drop Tower Facility also provided the same thermal and vacuum conditions used in the centrifuge, but was required to operate autonomously during free fall. Through the use of post synthesis instrumental characterization, it was found that increased gravity levels during synthesis, had the greatest effect on the final products. Samples produced in reduced and normal gravity appeared to form amorphous gels containing very small particles with moderate surface areas. Whereas crystalline anatase (TiO 2 ), was found to form in samples synthesized above 5 g with significant increases in crystallinity, particle size and surface area observed when samples were produced at gravity levels up to 70 g. It is proposed that for samples produced in higher gravity, an increased concentration gradient of water is forms at the bottom of the reacting film due to forced convection. The particles formed in higher gravity diffuse downward toward this excess of water, which favors the condensation reaction of remaining sol-gel precursors with the particles promoting increased particle growth. Due to the removal of downward convection in reduced gravity, particle growth due to condensation reaction processes are physically hindered hydrolysis reactions favored instead. Another significant finding from this work was that anatase could be produced at relatively low temperatures of 40-50°C instead of the conventional method of calcination above 450°C solely through sol-gel synthesis at higher gravity levels.

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“…This product is a metal alkoxide colloidal solution containing 7% silica and is normally used for the deposition of antireflective coatings on displays, but it has been used to detect chemical parameters in fiber optic sensors 20 and to fabricate optical waveguides. 21,22 The sensor is made up of a plastic cladding-silica core ͑PCS͒ multimode optic fiber pigtail ͑core and plastic cladding diameters 200 and 230 m, respectively͒, the end of which is cut with a Siemens S46999-M9-A8 precision fiber cleaver. The principal advantage of this fiber is the ease of removing its plastic cladding.…”

Section: Materials and Instrumentationmentioning

confidence: 99%

Volatile-organic-compound optic fiber sensor using a gold-silver vapochromic complex

Elosúa

2006

Opt. Eng

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We describe a new gold-silver complex based on 2,2Ј-bipyridine, whose formula is ͕Au 2 Ag 2 ͑C 6 F 5 ͒ 4 ͓͑C 5 H 4 N͒-͑C 5 H 4 N͔͒ 2 ͖ n , used to detect volatile organic compounds ͑VOCs͒ such as ethanol, methanol, and acetic acid. This organometallic material is presented in the form of bright yellow powder, and suffers a change in its optical properties when it is exposed to VOCs. A new fiber optic sensor is presented based on the properties of a new vapochromic material. The sensor works in a reflection configuration and consists of an optic fiber pigtail ͑core diameter is 200 m and cladding is 230 m͒ on the cleaved end of which the vapochromic material, previously mixed with a commercially available solvent, Liquicoat ® , is deposited by using the dip-coating technique. Using an optical source and a photodetector, it is possible to detect and quantify the change in reflected intensity-modulated signal when the sensor is exposed to VOC inside a sealed chamber. This behavior can be related to the VOC concentration. The study of the sensor's response is made at a specific wavelength for different VOC concentrations. Limits of detection of 2.16, 1.73, and 3.73 mg/ L of vapors of ethanol, methanol, and acetic acid vapors, respectively, are attained.

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Waveguide Raman spectroscopy of TiO2:SiO2 thin films

Cited by 20 publications

References 11 publications

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD

Synthesis and characterization of titanium sol–gels in varied gravity

Volatile-organic-compound optic fiber sensor using a gold-silver vapochromic complex

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Waveguide Raman spectroscopy of TiO2:SiO2 thin films

Cited by 20 publications

References 11 publications

Ion impingement effect on the structure and optical properties of TixSi1−xO2 films deposited by ICP‐PECVD

Ion impingement effect on the structure and optical properties of TixSi1−xO2 films deposited by ICP‐PECVD

Synthesis and characterization of titanium sol–gels in varied gravity

Volatile-organic-compound optic fiber sensor using a gold-silver vapochromic complex

Contact Info

Product

Resources

About

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD

Ion impingement effect on the structure and optical properties of Ti_xSi_1−xO₂ films deposited by ICP‐PECVD