Micro-Raman spectroscopy applied to polymers

1992 ◽  
Vol 50 (2) ◽  
pp. 1508-1509
Author(s):  
Robert J. Meier
Keyword(s):  
Raman Spectroscopy ◽  
Morphological Changes ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Micro Raman Spectroscopy ◽  
High Laser ◽  
Set Up ◽  
Microscopic Set ◽  
Anti Stokes ◽  
Micro Analysis

Over the last years micro-Raman spectroscopy has developed to a mature subdiscipline within the field of Raman spectroscopy. Its potential power seems obvious: (a) fluorescence suppression, a major obstacle in many Raman spectra; (b) micro-analysis of samples down to 1 μm lateral resolution yielding molecular information; (c) when using a confocal arrangement with the microscope, in addition to lateral resolution the depth resolution can be enhanced up to the 1 μm level.We applied micro-Raman spectroscopy over the last few years and recently developed a confocal Raman microscopic set-up. Our main application being in the field of polymers, the first thing to worry about is to what happens to the polymer sample when it is irradiated locally with a high laser power density. One should be warned even long before melting in order to avoid morphological changes because, after all, Raman spectroscopy is a powerful tool to study polymer morphology in detail. We use the Stokes/Anti-Stokes intensity ratio for determining the sample temperature.

Evaluation of Residual Stresses in Thin Films by Means of Micro-Raman Spectroscopy

1997 ◽  
Vol 505 ◽  
Author(s):  
Kazuyuki Mizuhara ◽  
Shinichi Takahashi ◽  
Jyunichi Kurokawa ◽  
Noboru Morita ◽  
Yoshitaro Yoshida
Keyword(s):  
Raman Spectroscopy ◽  
Temperature Effects ◽  
Simultaneous Observation ◽  
Stress Evaluation ◽  
Advantages And Disadvantages ◽  
Micro Raman Spectroscopy ◽  
Boron Doped ◽  
Doped Silicon ◽  
Fluid Cooling ◽  
Anti Stokes

ABSTRACTThe effects of temperatures on the stress evaluation of boron doped silicon in solid and film forms are investigated. Several techniques, such as fluid cooling to eliminate the temperature raise and/or simultaneous observation of Stokes and anti Stokes peaks to compensate the temperature effects, are applied. The advantages and disadvantages of each method and the abilities and limits of these techniques are discussed.

Analysis of grain orientation and intergrain properties by micro-Raman spectroscopy in YBa2Cu3O7−x thin films

2000 ◽  
Vol 15 (5) ◽  
pp. 1069-1075 ◽  
Author(s):  
O. Martínez ◽  
J. Jiménez ◽  
D. Chambonnet ◽  
C. Belouet
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Grain Boundaries ◽  
Grain Orientation ◽  
Structural Changes ◽  
Large Angle ◽  
Lateral Resolution ◽  
Micro Raman Spectroscopy ◽  
High Lateral Resolution

Superconducting YBa2Cu3O7−x (YBCO) thin films grown by pulser-laser-assisted deposition were studied by micro-Raman spectroscopy. This technique was used to estimate the epitaxial quality of the films in terms of the presence of c-axis- and a-axis-oriented areas. The advantage of micro-Raman spectroscopy is its high lateral resolution, and this was used to study the homogeneity of the films at submicrometric level. Local structural changes from a large number of intergrain regions were revealed by changes of the Raman parameters. For example, the aggregation of a-axis-oriented grains formed needle-shaped macrograins. Micro-Raman measurements suggest that these grains were seeded at large-angle grain boundaries in c-axis-oriented areas.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Micro-Raman Spectroscopy Evaluation of the Local Mechanical Stress in Shallow Trench Isolation CMOS Structures: Correlation with Defect Generation and Diode Leakage

1998 ◽  
Author(s):  
I. De Wolf ◽  
G. Groeseneken ◽  
H.E. Maes ◽  
M. Bolt ◽  
K. Barla ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Mechanical Stress ◽  
Defect Formation ◽  
Active Area ◽  
Wet Oxidation ◽  
Leakage Currents ◽  
Shallow Trench Isolation ◽  
Micro Raman Spectroscopy ◽  
Silicon Devices ◽  
Trench Isolation

Abstract It is shown, using micro-Raman spectroscopy, that Shallow Trench Isolation introduces high stresses in the active area of silicon devices when wet oxidation steps are used. These stresses result in defect formation in the active area, leading to high diode leakage currents. The stress levels are highest near the outer edges of line structures and at square structures. They also increase with decreasing active area dimensions.

Micro-Raman spectroscopy of Shang oracle bone inscriptions

2021 ◽  
Vol 37 ◽  
pp. 102910
Author(s):  
Jhih-Huei Liu ◽  
Weiying Ke ◽  
Ming-chorng Hwang ◽  
Kuang Yu Chen
Keyword(s):  
Raman Spectroscopy ◽  
Micro Raman Spectroscopy

Tissue Ki67 proliferative index expression and pathological changes in hemodialysis arteriovenous fistulae: Preliminary single-center results

2021 ◽  
pp. 112972982110154
Author(s):  
Raffaella Mauro ◽  
Cristina Rocchi ◽  
Francesco Vasuri ◽  
Alessia Pini ◽  
Anna Laura Croci Chiocchini ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Hot Spot ◽  
Wall Thickening ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Group A ◽  
The Mean ◽  
Set Up ◽  
Group B

Background: Arteriovenous fistula (AVF) for hemodialysis integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes. Aim of this study is to determine the role of Ki67, a well-established proliferative marker, related to AVF, and its relationship with time-dependent histological morphologic changes. Materials and methods: All patients were enrolled in 1 year and stratified in two groups: (A) pre-dialysis patients submitted to first AVF and (B) patients submitted to revision of AVF. Morphological changes: neo-angiogenesis (NAG), myointimal thickening (MIT), inflammatory infiltrate (IT), and aneurysmatic fistula degeneration (AD). The time of AVF creation was recorded. A biopsy of native vein in Group A and of arterialized vein in Group B was submitted to histological and immunohistochemical (IHC) analysis. IHC for Ki67 was automatically performed in all specimens. Ki67 immunoreactivity was assessed as the mean number of positive cells on several high-power fields, counted in the hot spots. Results: A total of 138 patients were enrolled, 69 (50.0%) Group A and 69 (50.0%) Group B. No NAG or MIT were found in Group A. Seven (10.1%) Group A veins showed a mild MIT. Analyzing the Group B, a moderate-to-severe MIT was present in 35 (50.7%), IT in 19 (27.5%), NAG in 37 (53.6%); AD was present in 10 (14.5%). All AVF of Group B with the exception of one (1.4%) showed a positivity for Ki67, with a mean of 12.31 ± 13.79 positive cells/hot spot (range 0–65). Ki67-immunoreactive cells had a subendothelial localization in 23 (33.3%) cases, a myointimal localization in SMC in 35 (50.7%) cases. The number of positive cells was significantly correlated with subendothelial localization of Ki67 ( p = 0.001) and with NA ( p = 0.001). Conclusions: Native veins do not contain cycling cells. In contrast, vascular cell proliferation starts immediately after AVF creation and persists independently of the time the fistula is set up. The amount of proliferating cells is significantly associated with MIT and subendothelial localization of Ki67-immunoreactive cells, thus suggesting a role of Ki-67 index in predicting AVF failure.

scholarly journals Use of WetSEM® capsules for convenient multimodal scanning electron microscopy, energy dispersive X-ray analysis, and micro Raman spectroscopy characterisation of technetium oxides

2021 ◽  
Author(s):  
D. J. Bailey ◽  
M. C. Stennett ◽  
J. Heo ◽  
N. C. Hyatt
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Powder Materials ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Hazard And Risk ◽  
Sem Imaging ◽  
General User ◽  
532 Nm

AbstractSEM–EDX and Raman spectroscopy analysis of radioactive compounds is often restricted to dedicated instrumentation, within radiological working areas, to manage the hazard and risk of contamination. Here, we demonstrate application of WetSEM® capsules for containment of technetium powder materials, enabling routine multimodal characterisation with general user instrumentation, outside of a controlled radiological working area. The electron transparent membrane of WetSEM® capsules enables SEM imaging of submicron non-conducting technetium powders and acquisition of Tc Lα X-ray emission, using a low cost desktop SEM–EDX system, as well as acquisition of good quality μ-Raman spectra using a 532 nm laser.

scholarly journals Influence of Different Conditioning Treatments on The Bond Integrity of Root Dentin to rGO Infiltrated Dentin Adhesive. SEM, EDX, FTIR and MicroRaman Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1555
Author(s):  
Firas Alqarawi ◽  
Mazen Alkahtany ◽  
Khalid Almadi ◽  
Afnan Gassem ◽  
Faris Alshahrani ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bond Strength ◽  
Strength Test ◽  
Control Group ◽  
Micro Raman Spectroscopy ◽  
Fiber Posts ◽  
Root Canal Disinfection ◽  
Reduced Graphene ◽  
Root Dentin ◽  
Push Out

The present study aimed to synthesize and equate the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and 5 wt.% reduced graphene oxide rGO) containing adhesive. Scanning electron microscopy (SEM)-Energy-dispersive X-ray spectroscopy (EDX), Micro-Raman spectroscopy, push-out bond strength test, and Fourier Transform Infrared (FTIR) spectroscopy were employed to study nano-bond strength, degree of conversion (DC), and adhesive-dentin interaction. The EA was prepared, and rGO particles were added to produce two adhesive groups, EA-rGO-0% (control) and rGO-5%. The canals of sixty roots were shaped and prepared, and fiber posts were cemented. The specimens were further alienated into groups based on the root canal disinfection technique, including 2.5% sodium hypochlorite (NaOCl), Photodynamic therapy (PDT), and ER-CR-YSGG laser (ECYL). The rGO nanoparticles were flake-shaped, and EDX confirmed the presence of carbon (C). Micro-Raman spectroscopy revealed distinct peaks for graphene. Push-out bond strength test demonstrated highest values for the EA-rGO-0% group after NaOCl and PDT conditioning whereas, rGO-5% showed higher values after ECYL conditioning. EA-rGO-0% presented greater DC than rGO-5% adhesive. The rGO-5% adhesive demonstrated comparable push-out bond strength and rheological properties to the controls. The rGO-5% demonstrated acceptable DC (although lower than control group), appropriate dentin interaction, and resin tag establishment.

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