A high-resolution energy-dispersive X-ray spectrometer (EDS) based on cryogenic microcalorimeter X-ray detectors has been developed for use in X-ray microanalysis. With an energy resolution of 3 eV at 1.5 keV, count rate of 500 s–1, and an effective collection area of 5 mm2 (using polycapillary X-ray optics), the microcalorimeter EDS combines many of the favorable qualities of commercially-available wavelength dispersive spectrometers (WDS) and semiconductor EDS. After describing the spectrometer system, we present several applications of microcalorimeter EDS to important microanalysis problems.
Concentration of carbon (C), oxygen (O), nitrogen (N), magnesium (Mg), aluminium (Al), silicon (Si), phosphorus (P), mercury (Hg), sulphur (S), lead (Pb), chlorine (Cl), potassium (K), cadmium (Cd), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu) and zinc (Zn), in the form of weight percentage, in the needles of different age classes, current and previous year one, of two sites, Risnjak National Park and Donja Dobra (control), were measured by X-ray microanalysis (EDAX) in the Scanning Electron Microscope in silver fir trees (Abies alba Mill.). The analysis suggests that accumulation of elements, in both years, particularly that of heavy metals, appeared in polluted site, like Risnjak, in the higher amount, whereas in non polluted, like Donja Dobra, in the lower amount. Moreover, it seems likely that elements at the first sites were accumulated and contaminated in very young current year needles, while in non polluted in somewhat older, the previous year ones.
-8100 spectrometer, KBr pellet technique), UV–Vis (SPECORD M40 type V-530), X-raymicroanalysis (Oxford X-ray analyzer ISIS 300) and SEM (JOEL JSM-6100 instrument).
In the epoxidation of allylic compounds the following raw materials were used: AA
by anodic striping. At the end of each step of the thermal mercury removal, the sample surface was examined using XRD, scanning electron microscopy (SEM), and energy dispersive X-raymicroanalysis (EDX). These techniques allowed to characterize, in
Samples of total suspended particles (TSP) and PM10 respirable particles from five monitoring stations from the network system
of the Metropolitan Zone of the Valley of Mexico (MZVM) were analyzed by scanning electron microscopy (SEM) and energy-dispersive
X-ray microanalysis (EDX). Morphology and chemical composition allowed to identify six groups. The analysis shows that the
most abundant groups are Al-Si-O, Fe, and metals, the first one in the TSP fraction. Trace metal, commonly associated to PM10
at a receptor location, will depend on the relative influences of local anthropogenic sources. Metal group was observed in
all samples, mainly in Tlalnepantla and CES zones (28–46%).
Particles composed of radioactive materials and probably originating from US nuclear weapons were identified in sea sediment samples collected from Thule, Greenland, in 1997. The weapons were destroyed close to the Thule Air Base in 1968 in an aeroplane crash, which dispersed radioactive materials in the environment. The presence of particulate radioactive materials in the sediment samples was revealed by combining gamma-spectrometry and autoradiography. Isolation and separation of a radioactive particle from a bulk sample were performed using autoradiography, phosphor plate imaging and scanning electron microscopy. Using X-ray microanalysis as well as alpha and beta activity analysis, U and weapons-grade Pu were detected in the granular, brittle particle.
In order to get insight in some of the yet unanswered questions about the formation process of the (Bi,Pb)2Sr2Ca2Cu3O10+δ superconducting compound, coupled DTA-TG measurements have been performed in parallel with other techniques such as X-ray diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray Microanalysis. The path leading to the formation of the (Bi,Pb)2Sr2Ca2Cu3O10+δ compound, starting from coprecipitated oxalates powders was studied. The activation energy of some of the involved transformation processes were determined. Relationships between the differences induced in the DTA traces by various sample nominal compositions and the intergranular magnetic properties of the superconductor will be discussed.
Analysis of very small particles can present problems. This paper describes the application of temperature programmed solid
insertion probe mass spectrometry (TP-SIP-MS), scanning electron microscopy and SEM X-ray microanalysis to the identification
of foreign particles present in an industrial product. The relative advantages and limitations of the techniques are discussed.
It is shown that TP-SIP-MS is a powerful tool for such work and complements the use of more conventional microanalytical methods.
Summary A conventional thermogravimeter has been adapted with a small magnet to detect the Curie temperature, TC. The measurements were performed in several Fe(Ni)NbB alloys developed in a nanocrystalline form by mechanical alloying. The B addition favors a slight diminution (10-20°C), and the Ni addition the existence of three transitions related with bccFe, fcc(Fe-Ni) abd fccNi-rich environments. Furthermore, complementary analysis were performed by means of differential thermal analysis, scanning electron microscopy with energy dispersive X-ray microanalysis and by induced coupled plasma. Small contamination was found. A mass increase (about 1 mass&) was detected by thermogravimetry related to oxidation. Analysis allows us to state the inhomogeneity of the alloys obtained after 80 h of milling.
The silica waste originating from a geothermal power plant in Mexico was investigated with the aim of finding its applicability
as a raw secondary material for ceramics production. The thermal behaviour of the original silica waste (containing NaCl and
KCl from marine brine) and of the purified silica was characterized by means of DTA/TG, emanation thermal analysis (ETA) and
thermodilatometry (TD). The reactivity of the purified silica waste mixed with CaCO3 (1.8 mass%) was characterized by means of ETA, DTA and TG. The microstructures and phase compositions of the final products
prepared by heating in air were tested by means of X-ray diffraction and of scanning electron microscopy coupled with electron
probe X-ray microanalysis. The thermal analysis methods allowed determination of the optimal conditions for thermal treatment
of the silica waste in order to obtain partly sintered porous materials for use as refractory bricks.