Cationic Ordering, Solid Solution Domain, and Diffuse Reflectance in Fe2WO6 Polymorphs

Author(s):  
Stéphane Caubergh ◽  
Nami Matsubara ◽  
Françoise Damay ◽  
François Fauth ◽  
Dmitry D. Khalyavin ◽  
...  
Clay Minerals ◽  
2016 ◽  
Vol 51 (4) ◽  
pp. 675-689 ◽  
Author(s):  
Vincent Trincal ◽  
Pierre Lanari

AbstractA compilation of Fe3+-bearing chlorite analyses is used: (1) to investigate the Alfree di-trioctahedral (AFDT) substitution 2Fe3++□= 3(Mg,Fe2+) in chlorite; and (2) to estimate the composition of a ferri-sudoite end-member (Si3Al)[(Fe2+,Mg)2□Al]O10(OH)8within the chlorite solid-solution domain. According to our observations, up to two Fe3+cations might be allocated in the M2-M3 chlorite sites by the substitution AFDT, which does not involve Al. These unexpected observations were made possible by the development of μXANES techniques allowingin situmeasurements ofXFe3+(Fe3+/(Fe2++ Fe3+)) in heterogeneous chlorite. Although further studies are required to confirm the crystallographic position of Fe3+ and refine its ionic/ magnetic behaviour in chlorite, this development creates opportunities for developing new geothermometers.


2012 ◽  
Vol 7 ◽  
pp. 33-38 ◽  
Author(s):  
Ana Gil-Martin ◽  
Bénédicte Arab-Chapelet ◽  
Murielle Rivenet ◽  
Stéphane Grandjean ◽  
Francis Abraham

1983 ◽  
Vol 37 (4) ◽  
pp. 348-354 ◽  
Author(s):  
Harry G. Hecht

Previous studies have shown that the Rozenberg and Pitts-Giovanelli methods are useful alternatives that may be applied to diffusely reflecting samples that fail to conform to the Kubelka-Munk theory. These studies are extended in the present work to include samples of three additional types, namely, those which incorporate the absorber in solid solution within the scattering particles, those in which the absorber is adsorbed on the surface of the scattering particles, and those consisting of a dye spotted on chromatographic papers. No single method of analysis is superior in all cases. Although the Pitts-Giovanelli method gives a much better fit in some cases, it fails to converge in others. For this reason the Kubelka-Munk and Rozenberg methods are preferred, particularly when applied to diffusers in a medium of refractive index n = 1. For such systems the Rozenberg equation reduces to a simple form that is as easy to apply as the Kubelka-Munk equation.


2014 ◽  
Vol 34 (2) ◽  
pp. 224-234 ◽  
Author(s):  
Leslie J. Janik ◽  
Sean T. Forrester ◽  
José M. Soriano-Disla ◽  
Jason K. Kirby ◽  
Michael J. McLaughlin ◽  
...  

Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.


Author(s):  
A. Christou ◽  
J. V. Foltz ◽  
N. Brown

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.


Author(s):  
Jordi Marti ◽  
Timothy E. Howson ◽  
David Kratz ◽  
John K. Tien

The previous paper briefly described the fine microstructure of a mechanically alloyed oxide dispersion strengthened nickel-base solid solution. This note examines the fine microstructure of another mechanically alloyed system. This alloy differs from the one described previously in that it is more generously endowed with coherent precipitate γ forming elements A1 and Ti and it contains a higher volume fraction of the finely dispersed Y2O3 oxide. An interesting question to answer in the comparative study of the creep and stress rupture of these two ODS systems is the role of the precipitate γ' in the mechanisms of creep and stress rupture in alloys already containing oxide dispersoids.The nominal chemical composition of this alloy is Ni - 20%Cr - 2.5%Ti - 1.5% A1 - 1.3%Y203 by weight. The system receives a three stage heat treatment-- the first designed to produce a coarse grain structure similar to the solid solution alloy but with a smaller grain aspect ratio of about ten.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


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