In Situ Metal Imaging and Zn Ligand-Speciation in a Soil-Dwelling Sentinel: Complementary Electron Microprobe and Synchrotron Microbeam X-ray Analyses

2012 ◽  
Vol 47 (2) ◽  
pp. 1073-1081 ◽  
Author(s):  
A. J. Morgan ◽  
J. F. W. Mosselmans ◽  
J. M. Charnock ◽  
A. Bennett ◽  
C. Winters ◽  
...  
Keyword(s):  
1998 ◽  
Vol 4 (S2) ◽  
pp. 180-181
Author(s):  
John T. Armstrong

Considering the heavy use by the geological community that followed, it is not surprising that first two authors of the introductory paper in Science on the energy dispersive x-ray spectrometer applied their x-ray microanalysis skills predominantly in the geological sciences. The energy dispersive spectrometer became first commercially available at an ideal time for the geological community. During the 1960’s, mineralogists and petrographers like K. Keil, J.V.P. Long, J.C. Rucklidge, J.V. Smith, A. Albee, and A. Chodos demonstrated that electron microprobe analysis with wavelength dispersive spectrometers could provide accurate in-situ analysis of portions of individual mineral grains on a scale not readily obtainable by other techniques (e.g., 2-3 and cited refs.). The electron microprobe enabled analysis of features observed by reflected- and transmitted-light polarized optical microscopy (prime tools of the mineralogist and petrographer) and was beginning to be used routinely for the study of meteorites and terrestrial rocks and even more exotic types of specimens, like individual microparticles from sediment and airborne particulate samples.


2017 ◽  
Vol 81 (5) ◽  
pp. 1261-1277 ◽  
Author(s):  
Tânia Martins ◽  
Ryan Kressall ◽  
Luca Medici ◽  
Anton R. Chakhmouradian

AbstractThis paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffraction) study of cancrinite-group minerals of relevance to alkaline igneous rocks. A solid solution is known to exist between cancrinite and vishnevite with the principal substitutions being CO32- by SO42- and Ca for Na. In the present study, several intermediate members of the cancrinite–vishnevite series from a syenitic intrusion at Cinder Lake (Manitoba, Canada), were used to examine how chemical variations in this series affect their spectroscopic and structural characteristics. The Cinder Lake samples deviate from the ideal cancrinite-vishnevite binary owing to the presence of cation vacancies. The only substituent elements detectable by electron microprobe are K, Sr and Fe (0.03-0.70, 0-0.85 and 0-0.45 wt.% respective oxides). The following Raman bands are present in the spectra of these minerals: ∼631 cm-1 and ∼984-986 cm-1 [SO42- vibration modes]; ∼720-774 cm -1 and ∼1045-1060 cm -1 [CO32- vibration modes]; and ∼3540 cm -1 and 3591 cm -1 [H2O vibration modes]. Our study shows a clear relationship between the chemical composition and Raman characteristics of intermediate members of the cancrinite-vishnevite series, especially with regard to stretching modes of the CO32- and SO42- anions. From cancrinite-poor (Ccn65) to cancrinite-dominant (Ccn913) compositions, the SO42- vibration modes disappear from the Raman spectrum, giving way to CO32- modes. X-ray microdiffraction results show a decrease in unit-cell parameters towards cancrinite-dominant compositions: a = 12.664 (1) Å, c = 5.173(1) Å for vishnevite (Ccn22); a = 12.613 (1) Å, c = 5.132(1) Å for cancrinite (Ccn71). Our results demonstrate that Raman spectroscopy and X-ray microdiffraction are effective for in situ identification of microscopic grains of cancrinite-vishnevite where other methods (e.g. infrared spectroscopy) are inapplicable. The petrogenetic implications of cancrinite-vishnevite relations for tracing early- to late-stage evolution of alkaline magmas are discussed.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
Karen A. Katrinak ◽  
James R. Anderson ◽  
Peter R. Buseck

Aerosol samples were collected in Phoenix, Arizona on eleven dates between July 1989 and April 1990. Elemental compositions were determined for approximately 1000 particles per sample using an electron microprobe with an energy-dispersive x-ray spectrometer. Fine-fraction samples (particle cut size of 1 to 2 μm) were analyzed for each date; coarse-fraction samples were also analyzed for four of the dates.The data were reduced using multivariate statistical methods. Cluster analysis was first used to define 35 particle types. 81% of all fine-fraction particles and 84% of the coarse-fraction particles were assigned to these types, which include mineral, metal-rich, sulfur-rich, and salt categories. "Zero-count" particles, consisting entirely of elements lighter than Na, constitute an additional category and dominate the fine fraction, reflecting the importance of anthropogenic air pollutants such as those emitted by motor vehicles. Si- and Ca-rich mineral particles dominate the coarse fraction and are also numerous in the fine fraction.


1997 ◽  
Vol 7 (C2) ◽  
pp. C2-619-C2-620 ◽  
Author(s):  
M. Giorgett ◽  
I. Ascone ◽  
M. Berrettoni ◽  
S. Zamponi ◽  
R. Marassi

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>


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