scholarly journals The Effect of Surface Treatment on Structural Properties of CVD Diamond Layers with Different Grain Sizes Studied by Raman Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1301
Author(s):  
Anna Dychalska ◽  
Wojciech Koczorowski ◽  
Marek Trzcinski ◽  
Lidia Mosińska ◽  
Mirosław Szybowicz
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Chemical Vapour ◽  
Cvd Diamond ◽  
Hydrogen Treatment ◽  
Layer Surface ◽  
Diamond Layer ◽  
Grain Sizes ◽  
Spectroscopy Studies ◽  
The Impact

Extensive Raman spectroscopy studies combined with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements were performed to investigate structural and chemical changes in diamond layers deposited by chemical vapour deposition (CVD) upon post-growth treatment with hydrogen. The aim of this study is to characterize the changes in micro-structural properties of diamond layers with different grain sizes and different contents of sp2 carbon phase. Hydrogenation or oxidization of diamond layer surface is often performed to modify its properties; however, it can also strongly affect the surface structure. In this study, the impact of hydrogenation on the structure of diamond layer surface and its chemical composition is investigated. Owing to their polycrystalline nature, the structural properties of CVD diamond layers can strongly differ within the same layer. Therefore, in this project, in order to compare the results before and after hydrogen treatment, the diamond layers are subjected to Raman spectroscopy studies in the vicinity of a T-shape marker fabricated on the surface of each diamond layer studied.

scholarly journals Revealing the local crystallinity of single silicon core-shell nanowires using tip-enhanced Raman spectroscopy

2020 ◽  
Author(s):  
Marius van den Berg ◽  
Ardeshir Moeinian ◽  
Arne Kobald ◽  
Yu-Ting Chen ◽  
Anke Horneber ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Silicon Nanowires ◽  
Chemical Vapour ◽  
Optical Resolution ◽  
Core Shell ◽  
Polarization Angle ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Tip Enhanced Raman Spectroscopy

Tip-enhanced Raman spectroscopy is combined with polarization angle-resolved spectroscopy to investigate the nanometre-scale structural properties of core-shell silicon nanowires (crystalline Si core and amorphous Si shell), which were synthesized by platinum-catalyzed vapor-liquid-solid growth and silicon overcoating by thermal chemical vapour deposition. Local changes in the fraction of crystallinity are characterized for those silicon nanowires at an optical resolution of about 300 nm. Furthermore, we are able to resolve the variations in the intensity ratios between the crystalline Si and the amorphous Si Raman peaks by applying tip-enhanced Raman spectroscopy, at sample positions being eight nanometers apart. The local crystallinity revealed using confocal Raman spectroscopy and tip-enhanced Raman spectroscopy agree well with the high-resolution transmission electron microscopy measurements. Additionally, the polarizations of Raman scattering and the photoluminescence signal from the tip-sample nanogap are explored by combining polarization angle-resolved emission spectroscopy with tip-enhanced optical spectroscopy. Our work demonstrates the significant potential of resolving local structural properties of Si nanomaterials at the sub-10 nanometer scale using tip-enhanced Raman techniques.

The effect of UV and thermally induced oxidation on the surface and structural properties of CVD diamond layers with different grain sizes

2021 ◽  
pp. 108739
Author(s):  
Anna Dychalska ◽  
Marek Trzcinski ◽  
Kazimierz Fabisiak ◽  
Kazimierz Paprocki ◽  
Wojciech Koczorowski ◽  
...  
Keyword(s):  
Structural Properties ◽  
Cvd Diamond ◽  
Thermally Induced ◽  
Grain Sizes

Impact of the Growth Parameters on the Structural Properties of Si0.8Ge0.2 Virtual Substrates

2005 ◽  
Vol 108-109 ◽  
pp. 445-450 ◽  
Author(s):  
Y. Bogumilowicz ◽  
J.M. Hartmann ◽  
F. Laugier ◽  
G. Rolland ◽  
Thierry Billon
Keyword(s):  
Growth Rate ◽  
Structural Properties ◽  
Growth Parameters ◽  
Strain Relaxation ◽  
Chemical Vapour ◽  
Root Mean Square Roughness ◽  
Threading Dislocation ◽  
Reduced Pressure ◽  
Threading Dislocation Density ◽  
The Impact

We have focused in this paper on the impact of the growth rate and of the grading rate on the structural properties of Si0.8Ge0.2 virtual substrates grown at 900°C in a commercial reduced pressure chemical vapour deposition reactor. Adopting a grading rate of 4% Ge / $m together with a growth rate around 140 nm min.-1 yields very high quality Si0.8Ge0.2 virtual substrates. Their macroscopic degree of strain relaxation is indeed very close to 100%, their surface root mean square roughness is around 2.3 nm and most importantly their field threading dislocation density is of the order of 6x104 cm-2 only, with almost no pile-ups.

Deposition of CVD diamond onto Zirconium

2015 ◽  
Vol 1734 ◽  
Author(s):  
F. Brannan ◽  
P.W. May ◽  
S.C. Halliwell ◽  
L. Payne
Keyword(s):  
Chemical Vapour ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Native Oxide ◽  
Diamond Layer ◽  
Cvd Growth ◽  
Lower Temperature ◽  
The Cost ◽  
Hot Filament ◽  
Bcc Phase

ABSTRACTThe growth of thin films of chemical vapour deposition (CVD) diamond onto flat samples of pure Zr has been studied using various CVD growth conditions in a hot filament reactor. We find that although growth is straightforward, adhesion of the diamond layer onto the Zr is poor, with the diamond layer often delaminating upon cooling. SIMS depth profiles show this to be due to the presence of a strongly-bonded native oxide on the Zr surface which is not removed in the reducing H2 atmosphere during CVD. This, plus the lack of any substantial carbide interfacial layer to ‘glue’ the diamond onto the surface, together with a poor thermal expansion mismatch between Zr and diamond, and the Zr hcp-to-bcc phase transition at ∼860°C, all lead to poor adhesion. Some of these difficulties can be reduced by depositing at lower temperature (<500°C) at the cost of poorer quality diamond.

scholarly journals Study of CVD diamond layers with amorphous carbon admixture by Raman scattering spectroscopy

2015 ◽  
Vol 33 (4) ◽  
pp. 799-805 ◽  
Author(s):  
Anna Dychalska ◽  
Piotr Popielarski ◽  
Wojciech Franków ◽  
Kazimierz Fabisiak ◽  
Kazimierz Paprocki ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Amorphous Carbon ◽  
Diamond Films ◽  
Standard Technique ◽  
Cvd Diamond ◽  
Chemical Vapor Deposition Method ◽  
First Order ◽  
Diamond Layer ◽  
Diamond Phase

AbstractRaman spectroscopy is a most often used standard technique for characterization of different carbon materials. In this work we present the Raman spectra of polycrystalline diamond layers of different quality, synthesized by Hot Filament Chemical Vapor Deposition method (HF CVD). We show how to use Raman spectroscopy for the analysis of the Raman bands to determine the structure of diamond films as well as the structure of amorphous carbon admixture. Raman spectroscopy has become an important technique for the analysis of CVD diamond films. The first-order diamond Raman peak at ca. 1332 cm−1 is an unambiguous evidence for the presence of diamond phase in the deposited layer. However, the existence of non-diamond carbon components in a CVD diamond layer produces several overlapping peaks in the same wavenumber region as the first order diamond peak. The intensities, wavenumber, full width at half maximum (FWHM) of these bands are dependent on quality of diamond layer which is dependent on the deposition conditions. The aim of the present work is to relate the features of diamond Raman spectra to the features of Raman spectra of non-diamond phase admixture and occurrence of other carbon structures in the obtained diamond thin films.

In Situ Raman Spectroscopy Studies on La2CaB10O19 Crystal Growth

2020 ◽  
Vol 20 (10) ◽  
pp. 6604-6609
Author(s):  
Shanshan Liu ◽  
Guochun Zhang ◽  
Kai Feng ◽  
Yanyang Han ◽  
Tao He ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Crystal Growth ◽  
In Situ Raman Spectroscopy ◽  
In Situ Raman ◽  
Spectroscopy Studies

scholarly journals Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Ana M. Herrero ◽  
Claudia Ruiz-Capillas
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Structural Changes ◽  
Protein Secondary Structure ◽  
Lipid Phase ◽  
Α Helix ◽  
Β Sheet ◽  
Shed Light ◽  
Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

2021 ◽  
Author(s):  
Linfei Yang ◽  
Jianjun Jiang ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Theoretical Calculations ◽  
Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

scholarly journals Raman scattering in high-refractive-index nanostructures

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Søren Raza ◽  
Anders Kristensen
Keyword(s):  
Raman Spectroscopy ◽  
Refractive Index ◽  
Raman Scattering ◽  
Bound States ◽  
Stimulated Raman Scattering ◽  
Dielectric Materials ◽  
High Refractive Index ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Enhancement ◽  
The Impact

AbstractThe advent of resonant dielectric nanomaterials has provided a new path for concentrating and manipulating light on the nanoscale. Such high-refractive-index materials support a diverse set of low-loss optical resonances, including Mie resonances, anapole states, and bound states in the continuum. Through these resonances, high-refractive-index materials can be used to engineer the optical near field, both inside and outside the nanostructures, which opens up new opportunities for Raman spectroscopy. In this review, we discuss the impact of high-refractive-index nano-optics on Raman spectroscopy. In particular, we consider the intrinsic Raman enhancement produced by different dielectric resonances and their theoretical description. Using the optical reciprocity theorem, we derive an expression which links the Raman enhancement to the enhancement of the stored electric energy. We also address recent results on surface-enhanced Raman spectroscopy based on high-refractive-index dielectric materials along with applications in stimulated Raman scattering and nanothermometry. Finally, we discuss the potential of Raman spectroscopy as a tool for detecting the optical near-fields produced by dielectric resonances, complementing reflection and transmission measurements.

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