Raman scattering study of a phase transition in tantalum pentoxide

Dobal, P. S.; Katiyar, Ram S.; Jiang, Yi; Guo, Ruyan; Bhalla, A. S.

doi:10.1002/1097-4555(200012)31:12<1061::aid-jrs644>3.0.co;2-g

Cited by 108 publications

(68 citation statements)

References 32 publications

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“…A discontinuous behavior of the external mode wavenumber at 397°C has been associated with a structural modification from lowsymmetry monoclinic to orthorhombic phase in 5% TiO 2 -doped Ta 2 O 5 . 15 −300 0 300 600 900 1200 with increasing TiO 2 content in Ta 2 O 5 . 15 However, we did not observe a sharp discontinuity in the wavenumber variation of Raman modes with temperature in pure or TiO 2 -substituted Nb 2 O 5 ceramics up to 1100°C.…”

Section: Resultsmentioning

confidence: 82%

Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Dobal

Dixit

Katiyar

et al. 2002

J Raman Spectroscopy

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Single-phase (Nb 2 O 5 ) 1−x (TiO 2 ) x ceramics were prepared for x = 0.00, 0.05, 0.08 and 0.11 compositions using a solid-state reaction technique. The effect of TiO 2 substitution on the vibrational and phase transition behavior of Nb 2 O 5 was studied using the micro-Raman scattering technique and compared with similar results on Ta 2 O 5 . The external modes resulting from interaction among various polyhedra were observed and vibrational changes were studied in the temperature range −200 to 1100 • C. An increase in structural disorder was reflected in the Raman spectra with increasing TiO 2 content in both Nb 2 O 5 and Ta 2 O 5 . Ta 2 O 5 shows a phase transition at about 300 • C . However, a low-temperature phase transition was observed about 50 • C from (Nb 2 O 5 ) 1−x (TiO 2 ) x compositions.

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Section: Resultsmentioning

confidence: 82%

Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Dobal

Dixit

Katiyar

et al. 2002

J Raman Spectroscopy

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“…The positions of the Raman peaks are also in good agreement with that reported Ta 2 O 5 with orthorhombic structure. 13) According to these results of XRD and RAMAN analysis, the as-grown tantalum oxide film is crystalline Ta 2 O 5 .…”

Section: Morphology and Phase Of Ta 2 O 5 Nanorodsmentioning

confidence: 99%

Optical and Electric Properties of Aligned-Growing Ta<SUB>2</SUB>O<SUB>5</SUB> Nanorods

Wang

Zhu

et al. 2008

Mater. Trans.

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These vertically aligned Ta 2 O 5 nanorods were deposited on Si (100) substrates by thermal deposition in a vacuum of the order of 10 À2 Torr at about 600 C. When excited by 514 nm Ar þ laser, they showed a strong photoluminescence at $622 nm, which was attributed to the oxygen vacancies. In addition, their dielectric constant is $20 in the frequency range from 1 kHz to 10 MHz, far larger than that of SiO 2 and Si 3 N 4 . Due to this cone-shaped morphology, the Ta 2 O 5 nanorods exhibited a threshold field of $8:5 V/mm in field emission and a field enhancement factor of 764 that are sufficiently high for field emission application.

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“…The planar waveguide and the PC slab structure are a desirable structure to realize a compact optical components device (e.g., tunable laser source). Among the available materials, the tantalum pentoxide (Ta 2 O 5 ) has received much attention due to its high refractive index (n > 2), low absorption over a wide wavelength region 0.3 to 10 m [4], high nonlinear refractive index n 2 = (7.23±0.36)×10 -19 m 2 /W [5], large value of chi 3 [6] and high optical damage threshold [7]. Recently, researchers have shown optical non-linear behaviour and demonstrated supercontinuum generation [8] and OPO [9] in Ta 2 O 5 waveguides, suggesting a good stability and high damage threshold limits.…”

Section: Introductionmentioning

confidence: 90%

Optimization of reactive-ion etching (RIE) parameters for fabrication of tantalum pentoxide (Ta₂O₅) waveguide using Taguchi method

et al. 2017

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Abstract. In this paper, we demonstrate the optimization of reactive-ion etching (RIE) parameters for the fabrication of tantalum pentoxide (Ta 2 O 5 ) waveguide with chromium (Cr) hard mask in a commercial OIPT Plasmalab 80 RIE etcher. A design of experiment (DOE) using Taguchi method was implemented to find optimum RF power, mixture of CHF 3 and Ar gas ratio, and chamber pressure for a high etch rate, good selectivity, and smooth waveguide sidewall. It was found that the optimized etch condition obtained in this work were RF power = 200 W, gas ratio = 80 %, and chamber pressure = 30 mTorr with an etch rate of 21.6 nm/min, Ta 2 O 5 /Cr selectivity ratio of 28, and smooth waveguide sidewall.

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Raman scattering study of a phase transition in tantalum pentoxide

Cited by 108 publications

References 32 publications

Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Optical and Electric Properties of Aligned-Growing Ta<SUB>2</SUB>O<SUB>5</SUB> Nanorods

Optimization of reactive-ion etching (RIE) parameters for fabrication of tantalum pentoxide (Ta₂O₅) waveguide using Taguchi method

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Raman scattering study of a phase transition in tantalum pentoxide

Cited by 108 publications

References 32 publications

Micro‐Raman scattering in Nb2O5–TiO2 ceramics

Micro‐Raman scattering in Nb2O5–TiO2 ceramics

Optical and Electric Properties of Aligned-Growing Ta<SUB>2</SUB>O<SUB>5</SUB> Nanorods

Optimization of reactive-ion etching (RIE) parameters for fabrication of tantalum pentoxide (Ta2O5) waveguide using Taguchi method

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Product

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Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Micro‐Raman scattering in Nb₂O₅–TiO₂ ceramics

Optimization of reactive-ion etching (RIE) parameters for fabrication of tantalum pentoxide (Ta₂O₅) waveguide using Taguchi method