Search results

1

Raman modes in transferred bilayer CVD graphene

100%

Niilisk A., Kahro T., Kiisk V., Rähn M., Alles H., Aarik J., Sammelselg V.

Open Physics

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2015

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vol. 13

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issue 1

EN

A systematic experimental Raman spectroscopic study of twisted bilayer graphene (tBLG) domains localized inside wide-area single layer graphene (SLG) produced by low-pressure CVD on Cu foil and transferred onto SiO2/Si substrate has been performed. According to the Raman characterization the tBLG domains had a great variety of twisting angles θ between the bottom and top graphene layers (6° < θ < 25°). The twisting angle θ was estimated from the spectral position of the rotating R and R' modes in the Raman spectrum.Under G band resonance conditions the breathing mode ZO' with a frequency of 95- 97 cm−1 was detected, and a breathing mode ZO was found in the spectra between 804 cm−1 and 836 cm−1, its position depending on the twisting angle θ. An almost linear relationship was found between the frequencies ωZO and ωR. Also a few other spectral peculiarities were found, e.g. a high-energy excitation of the G band resonance, the 2G overtone appearing at 3170-3180 cm−1 by the G band resonance, revealing a linear dispersion of 80 cm−1/eV of the 2D band in tBLG

2

Synthesis of carbon nanotubes via chemical vapor deposition by using rareearth metals as catalysts

100%

Jędrzejewska A., Wnuk K., Kaleńczuk R., Borowiak-Paleń E.

Polish Journal of Chemical Technology

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2010

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vol. 12

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issue 3

29-32

EN

This work presents the results of the synthesis of carbon nanotubes using the CVD method. Fe: MgO catalyst was used, also in combination with rare earth elements (gadolinium (Gd), dysprosium (Dy)), which when used alone, are not efficient as catalysts in nanotube growth. Synthesis was performed both at reduced pressure (10-3 mbar) and atmospheric pressure, with constant parameters dependent on the process parameters.

3

Badania meteorytu Odessa przy użyciu nowoczesnych technik inżynierii materiałowej

100%

Ferdzyn J., Gołdyn P., Kędzierski Ł., Radaszkiewicz A., Sroczyńska A., Jędrzejczak-Gruszczyńska A., Makówka M., Karczemska A.

Acta Societatis Metheoriticae Polonorum

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2017

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vol. 8

40-51

EN

Odessa iron meteorite was investigated with scanning electron microscopy (SEM), Raman spectroscopy and X-ray diffraction (XRD) techniques. The research has shown the existence of minerals such as schreibersite, troilite, taenite, kamacite, cohenite, graphite and diamond in the examined sample. Raman spectroscopy allowed to identify different allotropic forms of carbon, which is diamond and graphite with different levels of order.

4

Charakterystyka ałtaitu z meteorytu Morasko metodą spektroskopii Ramana

100%

Runka T., Karwowski Ł., Muszyński A.

Acta Societatis Metheoriticae Polonorum

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2012

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vol. 3

159-160

5

Raman studies of Pd-C nanocomposites

100%

Belka R., Suchanska M., Czerwosz E., Keczkowska J.

Open Physics

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2013

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vol. 11

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issue 2

245-250

EN

The results of studying palladium-carbon (Pd-C) nanocomposites using Raman spectroscopy are presented. This method has been used for studying samples having various palladium content, prepared by a one-step Physical Vapour Deposition (PVD) process and a Chemical Vapour Deposition (two-step PVD/CVD) process using different process parameters. For samples obtained by PVD, the vibration bands characteristic of C60 fullerene molecules were observed in the spectra, whereas for layers obtained by PVD/CVD, the Raman spectra displayed mainly D and G bands characteristic solely of the prescence of graphite-like layers’ vibrations. The analysis of the obtained Raman spectra reveals that its shape is affected by many parameters including type of substrate, temperature, and the percentage content of Pd in the studied layer. The quantitative analysis of spectra for layers obtained using the PVD/CVD process shows a difference in the relative intensity of bands D and G, reflecting the different degrees of amorphisation in the investigated nanocomposites.

6

Preliminary spectroscopic investigation of some PVA membranes gamma irradiated

100%

Todica M., Udrescu L., Şimon S.

Open Physics

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2012

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vol. 10

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issue 2

329-334

EN

The UV-VIS absorption property and the structural modification of PVA membranes gamma irradiated were investigated by XRD, UV-VIS and Raman spectroscopies. The increase of UV absorbance is observed after irradiation. This behavior is correlated with the scission effect and local ordering of the polymeric chain induced by irradiation. These effects were probed by XRD and Raman spectroscopy.

7

The influence of thermal annealing on structure and oxidation of iron nanowires

88%

Krajewski M., Brzózka K., Górka B., Lin W.-S., Lin H.-M., Szumiata T., Gawroński M., Wasik D.

Nukleonika

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2015

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vol. 60

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issue 1

87-91

EN

Raman spectroscopy as well as Mössbauer spectroscopy were applied in order to study the phase composition of iron nanowires and its changes, caused by annealing in a neutral atmosphere at several temperatures ranging from 200°C to 800°C. As-prepared nanowires were manufactured via a simple chemical reduction in an external magnetic field. Both experimental techniques proved formation of the surface layer covered by crystalline iron oxides, with phase composition dependent on the annealing temperature (Ta). At higher Ta, hematite was the dominant phase in the nanowires.

8

Characterisation of Ni-C films obtained in PVD/CVD process

88%

Kęczkowska J.

Open Physics

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2011

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vol. 9

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issue 2

330-337

EN

The work presents the results of the scanning electron microscopy (SEM) and Raman spectrometry studies of carbonaceous nanostructures containing nickel nanocrystallites. The films were obtained using a two-step method. In the first phase the Physical Vapour Deposition (PVD) method was applied, whereas in the second Chemical Vapour Deposition (CVD) method was used. The paper presents results for samples with various Ni content obtained with different parameters of the two-phase technological process. The research confirms that the thin films obtained by PVD method contain Ni nanocrystallites distributed in a carbonaceous matrix. The matrix is composed of various carbon allotropes (amorphous carbon, graphite, fullerene). The thin films made by CVD method make a matrix when multiwalled, carbonaceous nanotubes are obtained. Depending on the technological process parameters of each phase, we obtain multiwall nanotubes with a various degree of defects.

9

Preliminary spectroscopic investigation of tacrolimus TiO2 system

88%

Todica M., Udrescu L.

Open Physics

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2011

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vol. 9

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issue 6

1536-1539

EN

The effect of air and UV exposure on the tacrolimus was observed by Raman and UV VIS spectroscopy. For moderate time exposure the chemical structure of tacrolimus is not affected. The absorption property of tacrolimus was enhanced by addition of TiO2.

10

Microstructural Characterization of Cast Magnesium Matrix Composites by Raman Microscopy

88%

Malik M. A., Braszczyńska-Malik K. N., Majchrzak K.

Archives of Foundry Engineering

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2013

|

issue 1

11

Algorithms of Chemicals Detection Using Raman Spectra

88%

Wierzba P., Kwiatkowski A., Smulko J., Gnyba M.

Metrology and Measurement Systems

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2010

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issue 4

12

Chemical stability of plasmon-active silver tips for tip-enhanced Raman spectroscopy

75%

Kalbacova J., Rodriguez R. D., Desale V., Schneider M., Amin I., Jordan R., Zahn D. R. T.

Nanospectroscopy

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2014

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vol. 1

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issue 1

EN

Silver nanostructures are used in tip- and surface-enhanced Raman spectroscopy due to their high electric field enhancement over almost the entire visible spectral range. However, the low chemical stability of silver, compared to other noble metals, promotes silver sulfide and sulfate formation which decreases its plasmonic activity. This is why silver tips are usually prepared on the same day of the experiments or are disregarded in favour of gold that is chemically more stable. Since silver degradation cannot be avoided, we hypothesized that a protection layer may be able to minimize or control degradation. In this contribution, we report the successful preparation of 4-biphenylthiol and 4’-nitro-4-biphenylthiol self-assembled monolayers on silver tips in order to protect them against tarnishing and to investigate the effect on the life-time of the plasmonic activity. The electrochemically etched wire surface was probed via Raman spectroscopy and scanning electron microscopy. The best long term stability and resistance against corrosion was shown by a monolayer of 4-biphenylthiol formed from dimethylformamide which did not display any degradation of the metallic tip during the observed period. Here, we demonstrate an easy and straightforward approach towards increasing the chemical stability of silver TERS-active probes.

13

Thermal history of the Carboniferous strata in the northern part of the Intra-Sudetic Basin (SW Poland): A combined Raman spectroscopy and organic petrography study

75%

Botor D., Toboła T., Waliczek M., Botor D., Toboła T., Waliczek M.

Acta Geologica Polonica

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2020

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vol. 70

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issue 3

14

Segregated network polymer/carbon nanotubes composites

75%

Mierczynska A., Friedrich J., Maneck H., Boiteux G., Jeszka J.

Open Chemistry

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2004

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vol. 2

|

issue 2

363-370

EN

In this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.

15

Surface and interface properties of thin pentacene and parylene layers

75%

Vincze A., Jakabovič J., Srnánek R., Šatka A., Kovac J.

Open Physics

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2009

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vol. 7

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issue 2

270-278

EN

To improve Organic Thin Film Transistor (OTFT) properties we study OTFT semiconductor/dielectric interfacial properties via examination of the gate dielectric using thin Parylene C layer. Structural and morphology properties of pentacene layers deposited on parylene layer and SiO2/Si substrate structure were compared. The surface morphology was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM). AFM topography of pentacene layer in non-contact mode confirmed the preferable pentacene grain formation on parylene surface in dependence on layer thickness. The distribution of chemical species on the surfaces and composition depth profiles were measured by secondary ion mass spectroscopy (SIMS) and surface imaging. The depth profiles of the analyzed structures show a homogenous pentacene layer, characterized with C or C2 ions. Relatively sharp interface between pentacene and parylene layers was estimated by characteristic increased intensity of CCl ions peak. For revealing the pentacene phases in the structures the Micro-Raman spectroscopy was utilized. Conformal coatings of parylene and pentacene layers without pinholes resulted from the deposition process as was confirmed by SIMS surface imaging. For the pentacene layers thicker than 20 nm, both thin and bulk pentacene phases were detected by Micro-Raman spectroscopy, while for the pentacene layer thickness of 5 and 10 nm the preferable thin phase was detected. The complete characterisation of pentacene layers deposited on SiO2 and parylene surface revealed that the formation of large grains suggests 3D pentacene growth at parylene layer with small voids between grains and more than one monolayer step growth. The results will be utilized for optimization of the deposition process.

16

Examination of the Properties of Samples from Glass-Epoxy Core Rods for Composite Insulators Subjected to DC High Voltage

75%

Wieczorek K., Jaroszewski M., Ranachowski P., Ranachowski Z.

Archives of Metallurgy and Materials

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2018

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vol. 63

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issue 3

17

Raman Spectroscopy Studies of Carbon-Based Cathode Materials during Aluminum Electrolysis

75%

Wang W., Chen W., Wang W., Chen W.

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issue 4

18

Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy

75%

Głowacki M. J., Gnyba M., Strąkowska P., Gardas M., Kraszewski M., Trojanowski M., Strąkowski M. R.

Metrology and Measurement Systems

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2017

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vol. 24

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issue 1

19

Fabrication and characterization of 1-D alumina (Al2O3) nanofibers in an electric field

75%

Azad A.-M., Noibi M., Ramachandran M.

Bulletin of the Polish Academy of Sciences: Technical Sciences

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2007

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vol. 55

|

issue 2

20

Extension of solid immersion lens technology to super-resolution Raman microscopy

63%

Ostertag E., Lorenz A., Rebner K., Kessler R. W., Meixner A. J.

Nanospectroscopy

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2014

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vol. 1

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issue 1

EN

Scanning Near-Field Optical Microscopy (SNOM) has developed during recent decades into a valuable tool to optically image the surface topology of materials with super-resolution. With aperture-based SNOM systems, the resolution scales with the size of the aperture, but also limits the sensitivity of the detection and thus the application for spectroscopic techniques like Raman SNOM. In this paper we report the extension of solid immersion lens (SIL) technology to Raman SNOM. The hemispherical SIL with a tip on the bottom acts as an apertureless dielectric nanoprobe for simultaneously acquiring topographic and spectroscopic information. The SIL is placed between the sample and the microscope objective of a confocal Raman microscope. The lateral resolution in the Raman mode is validated with a cross section of a semiconductor layer system and, at approximately 180 nm, is beyond the classical diffraction limit of Abbe.

Refine search results

Raman modes in transferred bilayer CVD graphene

Synthesis of carbon nanotubes via chemical vapor deposition by using rareearth metals as catalysts

Badania meteorytu Odessa przy użyciu nowoczesnych technik inżynierii materiałowej

Charakterystyka ałtaitu z meteorytu Morasko metodą spektroskopii Ramana

Raman studies of Pd-C nanocomposites

Preliminary spectroscopic investigation of some PVA membranes gamma irradiated

The influence of thermal annealing on structure and oxidation of iron nanowires

Characterisation of Ni-C films obtained in PVD/CVD process

Preliminary spectroscopic investigation of tacrolimus TiO2 system

Microstructural Characterization of Cast Magnesium Matrix Composites by Raman Microscopy

Algorithms of Chemicals Detection Using Raman Spectra

Chemical stability of plasmon-active silver tips for tip-enhanced Raman spectroscopy

Thermal history of the Carboniferous strata in the northern part of the Intra-Sudetic Basin (SW Poland): A combined Raman spectroscopy and organic petrography study

Segregated network polymer/carbon nanotubes composites

Surface and interface properties of thin pentacene and parylene layers

Examination of the Properties of Samples from Glass-Epoxy Core Rods for Composite Insulators Subjected to DC High Voltage

Raman Spectroscopy Studies of Carbon-Based Cathode Materials during Aluminum Electrolysis

Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy

Fabrication and characterization of 1-D alumina (Al2O3) nanofibers in an electric field

Extension of solid immersion lens technology to super-resolution Raman microscopy