D066 Measurement and Modeling of Internal Stresses at Microscopic and Mesoscopic Levels Using Micro Raman Spectroscopy and X-ray Diffraction

2005 ◽  
Vol 20 (2) ◽  
pp. 177-177
Author(s):  
B. Benedikt ◽  
M. Lewis ◽  
P. Rangaswamy
2006 ◽  
Vol 21 (2) ◽  
pp. 118-121 ◽  
Author(s):  
B. Benedikt ◽  
M. Lewis ◽  
P. Rangaswamy

In this study, we use X-ray diffraction (XRD) and micro-Raman spectroscopy (MRS) to measure internal strains in sensors embedded in polymer matrix composites. Two types of strain sensors embedded in either chopped graphite fiber∕epoxy matrix composite (MRS) or unidirectional graphite fiber∕polyimide matrix composite (XRD) were investigated. For XRD measurements, the sensors were in the form of spherical aluminum inclusions with diameters ranging from 1 to 20 μm. Due to large cross section area of an incident X-ray beam, only average stresses are reported using the XRD approach. Complementary to XRD experiments, MRS was pursued to measure internal strains in Kevlar-49 fibers embedded in chopped graphite fiber∕epoxy matrix composite. In recent years, MRS as an experimental tool for microstrain measurements has drawn considerable attention mostly due to its excellent spatial resolution. The resolution of MRS typically ranges between 1 and 10 μm, which means that strains can be measured in individual sensors. The principle of this method relies on a change of certain molecular vibration frequencies as a result of an applied stress. Several examples are presented and discussed to demonstrate the potential of combining micro and macrostrain measurements and modeling to capture the stress distribution in heterogeneous materials.


2005 ◽  
Vol 20 (12) ◽  
pp. 3270-3273 ◽  
Author(s):  
F. Berberich ◽  
H. Graafsma ◽  
B. Rousseau ◽  
A. Canizares ◽  
R. Ramy Ratiarison ◽  
...  

A unique combination of in situ synchrotron x-ray diffraction and in situ micro-Raman spectroscopy was used to study the growth process of YBa2Cu3O6+x films obtained by metal organic decomposition using trifluoroacetate precursor on LaAlO3 substrates. The techniques give complementary information: x-ray diffraction gives insight into the structural growth, whereas micro-Raman spectroscopy gives information of the chemical composition with additional information on the texture. To perform both experiments in situ, a special high-temperature process chamber was designed.


2012 ◽  
Vol 60 ◽  
pp. 124-128 ◽  
Author(s):  
Aleksandra Wesełucha-Birczyńska ◽  
Sylwia Zelek ◽  
Katarzyna Stadnicka

2012 ◽  
Vol 27 (2) ◽  
pp. 131-136
Author(s):  
Bozidar Cekic ◽  
Valentin Ivanovski ◽  
Aleksandar Djordjevic ◽  
Velimir Aleksic ◽  
Zorica Tomic ◽  
...  

The paper addresses the issue of health risk associated with the presence of chrysotile in the soil type ranker formed on massive serpentines occurring in the area of Bubanj Potok, a settlement located in the southern Belgrade environs, Serbia. Characterization of the ranker soil was conducted by scanning electron microscopy, X-ray diffraction, micro-Raman spectroscopy and transmission 57Fe M?ssbauer spectroscopy. Scanning electron microscopy figures showed regular shaped smectite (montmorillonite) particles, aggregates of chlorite, and elongated sheets of serpentines minerals antigorite. X-ray diffraction analysis confirmed the presence of detrital mineral quartz polymorph as well as minor amounts of other mineral species. Micro-Raman spectroscopy identified the presence of dominant minerals, such as montmorillonite, kaolinite, muscovite, gypsum, calcite, albite, amphiboles (hornblende/kaersutite) and orthoclase. Important polymorph silica modifications of quartz, olivine (forsterite), pyroxene (enstatite/ferrosilite, diopside/hedenbergite), and serpentine (antigorite/lizardite/chrysotile) were identified.


2005 ◽  
Vol 40 (16) ◽  
pp. 4293-4298 ◽  
Author(s):  
S. N. Tkachev ◽  
M. H. Manghnani ◽  
A. Niilisk ◽  
J. Aarik ◽  
H. Mändar

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 188
Author(s):  
Arun Kumar ◽  
Michele Cassetta ◽  
Marco Giarola ◽  
Marco Zanatta ◽  
Monique Le Guen ◽  
...  

This study is focused on the vibrational and microstructural aspects of the thermally induced transformation of serpentine-like garnierite into quartz, forsterite, and enstatite occurring at about 620 °C. Powder specimens of garnierite were annealed in static air between room temperature and 1000 °C. The kinetic of the transformation was investigated by means of thermogravimetric and differential thermal analysis, and the final product was extensively characterized via micro-Raman spectroscopy and X-ray diffraction. Our study shows that serpentine-like garnierite consists of a mixture of different mineral species. Furthermore, these garnierites and their composition can provide details based on the mineralogy and the crystalline phases resulting from the thermal treatment.


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