Determination of optical constants of tantalum oxide thin film deposited by electron beam evaporation

Kumar, Mukesh; Kumari, Neelam; Kumar, Vsrs Praveen; Karar, Vinod; Sharma, Amit

doi:10.1016/j.matpr.2017.11.629

Cited by 6 publications

(3 citation statements)

References 25 publications

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“…It is known that this rotation during OAD gives rise to a microstructure formed by vertical nanocolumns. , Figure shows a schematic representation of the deposition setup and the typical nanocolumn structure formation induced with this procedure. More detailed information about the preparation and properties of single layers of these materials can be found in refs − , − . All samples were annealed at 400 °C in air for 3 h to induce the crystallization of the titania layers into the photocatalytically active anatase phase (a-TiO 2 ) of this oxide.…”

Section: Methodsmentioning

confidence: 99%

Titania Enhanced Photocatalysis and Dye Giant Absorption in Nanoporous 1D Bragg Microcavities

Rico

Turk

Yubero

et al. 2022

ACS Appl. Nano Mater.

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Light trapping effects are known to boost the photocatalytic degradation of organic molecules in 3D photonic structures of anatase titania (a-TiO 2 ) with an inverse opal configuration. In the present work, we show that photocatalytic activity can also be enhanced in a-TiO 2 thin films if they are incorporated within a nanoporous 1D optical resonant microcavity. We have designed and manufactured multilayer systems that, presenting a high open porosity to enable a straightforward diffusion of photodegradable molecules, provide light confinement effects at wavelengths around the absorption edge of photoactive a-TiO 2 . In brief, we have observed that a nanoporous 1D Bragg microcavity prepared by electron beam evaporation at oblique angles comprising a central defect layer of nanoporous a-TiO 2 boosts the photocatalytic degradation of nitrobenzene and methyl orange dye solutions. The multilayer structure of the microcavity was designed to ensure the appearance of optical resonances at the a-TiO 2 layer location and wavelengths around the absorption onset of this semiconductor. In this porous 1D Bragg microcavity, the diffusion constraints of molecules through the capping layers covering the a-TiO 2 are effectively compensated by an increase in the photocatalytic activity due to the light confinement phenomena. We also report that the absorption coefficient of methyl orange dye solution infiltrated within the pore structure of the microcavity is exalted at the wavelengths of the corresponding optical resonances. This effect gives rise to a small but non-negligible visible light photodegradation of dye molecules. The possibilities of tailoring the design of 1D photonic systems to boost the photocatalytic activity of a-TiO 2 are discussed.

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Section: Methodsmentioning

confidence: 99%

Titania Enhanced Photocatalysis and Dye Giant Absorption in Nanoporous 1D Bragg Microcavities

Rico

Turk

Yubero

et al. 2022

ACS Appl. Nano Mater.

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“…According to the requirements of the spectrum, Ta 2 O 5 and SiO 2 were selected as high− and low−refractive−index materials, respectively. Ta 2 O 5 has a transparent region of 0.35~10 µm, with a high refractive index and low absorption [28,29]. SiO 2 has a transparent region of 0.2~9 µm, with good optical and chemical stability.…”

Section: πmentioning

confidence: 99%

Development of Visible Multi−Bandpass Filter Based on F−P Structure

Jiang,

Fan,

et al. 2023

Coatings

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In order to reduce the noise interference of smart wearable devices, spectral filtering technology is used to suppress noise. This technology prevents interference signals from entering the detector from the source, thereby achieving high−precision noise reduction processing. According to the system requirements, a multi−bandpass filter with a wavelength range of 400~1000 nm was designed and prepared on a BK7 substrate. Ta2O5 and SiO2 were selected as the high− and low−refractive−index materials, respectively. By analyzing the −Fabry–Perot narrowband theory, the bandwidth matching coefficient was computed, and the interference order was calculated using the interval of the transmission peak wavelengths. Multiple F−P coating systems were connected through the matching layer to adjust the position of the transmission peak and broaden the bandwidth range. The design was optimized using Macloed film system design software, resulting in the design of a wide half−wave and cutoff multi−bandpass filter. The appropriate preparation process was chosen based on changes in refractive index, surface roughness, and the temperature gradient of the materials. The filter was then produced using Leybold SYRUSpro1110. Sensitivity, filter roughness, and the weak absorption of the film system were tested, and the results met the system requirements.

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“…Since the approach for the deposition of the Ta coatings involves changing the structure and properties of materials at both the micro- and nanoscales, it is advisable to assess changes in the structure and properties at these levels. Such instrumental research methods as atomic force microscopy (AFM) and nanoindentation (NI) allow studying the surface properties of the films of tantalum and its compounds at the nanoscale, as well as to evaluate the nature of their changes (roughness, friction coefficient) in the biological medium and estimate the possibility of using these nanocoatings as biocompatible materials [ 37 , 38 , 39 , 40 ].…”

Section: Introductionmentioning

confidence: 99%

Nanomechanical and Nanotribological Properties of Nanostructured Coatings of Tantalum and Its Compounds on Steel Substrates

et al. 2021

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The present paper addresses the problem of identification of microstructural, nanomechanical, and tribological properties of thin films of tantalum (Ta) and its compounds deposited on stainless steel substrates by direct current magnetron sputtering. The compositions of the obtained nanostructured films were determined by energy dispersive spectroscopy. Surface morphology was investigated using atomic force microscopy (AFM). The coatings were found to be homogeneous and have low roughness values (<10 nm). The values of microhardness and elastic modulus were obtained by means of nanoindentation. Elastic modulus values for all the coatings remained unchanged with different atomic percentage of tantalum in the films. The values of microhardness of the tantalum films were increased after incorporation of the oxygen and nitrogen atoms into the crystal lattice of the coatings. The coefficient of friction, CoF, was determined by the AFM method in the “sliding” and “plowing” modes. Deposition of the coatings on the substrates led to a decrease of CoF for the coating-substrate system compared to the substrates; thus, the final product utilizing such a coating will presumably have a longer service life. The tantalum nitride films were characterized by the smallest values of CoF and specific volumetric wear.

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Determination of optical constants of tantalum oxide thin film deposited by electron beam evaporation

Cited by 6 publications

References 25 publications

Titania Enhanced Photocatalysis and Dye Giant Absorption in Nanoporous 1D Bragg Microcavities

Titania Enhanced Photocatalysis and Dye Giant Absorption in Nanoporous 1D Bragg Microcavities

Development of Visible Multi−Bandpass Filter Based on F−P Structure

Nanomechanical and Nanotribological Properties of Nanostructured Coatings of Tantalum and Its Compounds on Steel Substrates

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