Encontrados 11 documentos, a visualizar página 1 de 2
Ball-milling in vacuum of [alpha] and [sigma] phases of near-equiatomic FeCr al...
Costa, B.F.O.; Le Caër, G.; Loureiro, J.M.http://www.sciencedirect.com/science/article/B6TWY-4V34RFW-N/2/c9147c3fe84413d6b8e8875146fc1b0b
Delayed electron capture and Mu- formation in ZnSe
Vilão, R. C.; Gil, J. M.; Weidinger, A.; Alberto, H. V.; Piroto Duarte, J.; Costa, B. F. O.; Ayres de Campos, N.; Lichti, R. L.; Chow, K. H.http://www.sciencedirect.com/science/article/B6TVH-4V2NP2J-1R/2/ae8c94d2ee3229b6fe7881d93d1a64eb
Hydrogen effect on the sigma-phase in Fe53.8Cr46.2
Cieslak, J.; Costa, B. F. O.; Dubiel, S. M.; Fruchart, D.; Skryabina, N. E.Investigation of the stability and properties of a sigma-phase type compound Fe53.8Cr46.2 after electrochemical hydrogen treatment was made using X-ray diffraction and 57Fe Mössbauer spectroscopy techniques. The amount of the hydrogen uptake was estimated to be equal to ~1.2H per unit formula, and its presence leads to an anisotropic cell parameter expansion. However, the hydrogenated state appears as metastabl...
Magnetic and transport studies of [sigma]-phase Fe50V50 alloys with different t...
Costa, B. F. O.; Amaral, V. S.; Le Caër, G.; Braga, M. E.; Amado, M. M.; Rocco, D. L.; Sousa, J. B.http://www.sciencedirect.com/science/article/B6TXM-4TRM3MB-3/2/a3801608d0695335d1eccf6692a4287d
Mössbauer spectroscopy and X-ray diffraction studies of ball-milling-induced tr...
Costa, B. F. O.; Caër, G. Le; Malaman, B.; Batista, A. C.57Fe Mössbauer spectroscopy and X-ray diffraction were used to study the structural changes induced by ball milling a coarse-grained Fe48.1V51.9 at% sigma phase in a vibratory mill in argon with a frequent gas renewal. The sigma phase transforms into a bcc alpha phase till 140 h of milling. Mössbauer spectroscopy also shows the presence of an amorphous phase. Further, X-ray diffraction and Mössbauer spectroscop...
X-ray diffraction and Mössbauer spectrometry studies of molecular iron compounds
Costa, B. F. O.; Greneche, J. M.; Silva, M. Ramos; Pereira, L. C. J.We have synthesized two new iron complexes that have been structural and magnetically characterized: diphenylguanidinium hexafluoroferrate and hexakisvaline-oxo-triiron(III) chloride. The former crystallizes as monomers with the fluoride ions six-coordinating the Fe(II) ion. Valine iron chloride is comprised of trinuclear complexes, with a well ordered oxo-centered carboxylate core and some disordered organic l...
Structural analysis and 57Fe Mössbauer spectrometry of Zr6FeSn2 and related com...
Costa, B. F. O.; Greneche, J. M.; Fruchart, D.; Alberto, H. V.; Skryabina, N. E.; Romaka, L. P.; Stadnyk, Yu. V.Hexagonal compounds of formula Zr6FeX2 were prepared and studied by X-ray and neutron diffraction and by 57Fe Mössbauer spectroscopy. The first results indicate that most of the compounds can be prepared mainly as a single phase after at least 5 weeks of annealing at a temperature close to 900 °C. In particular, the hyperfine parameter distributions in Mössbauer spectra reflect the ability to form pure phases. ...
Mechanically induced phase transformations of the sigma phase of nanograined an...
Costa, B. F. O.; Caër, G. Le; Loureiro, J. M.; Amaral, V. S.A coarse-grained tetragonal sigma phase [sigma]-Fe0.54Cr0.46, prepared from an as-cast alloy, and a nanocrystalline [sigma]-Fe0.52Cr0.48 phase were ball-milled in argon in a Fritsch P0 ball-mill at different vibration amplitudes. X-ray diffraction evidences solely a gradual transformation of the sigma phases into bcc phases. Room-temperature Mössbauer spectroscopy shows further the presence of a non-magnetic ph...
A technical note on the phase transformation in furnace container material afte...
Loureiro, A. J. R.; Costa, B. F. O.The aim of this work is to investigate the metallurgical changes in the wall of cylindrical containers, fabricated by welding from AISI 310 steel, used in the thermal and chemical treatment of spindle chains for the automotive industry, for an in-service period of over 1000 h. In order to identify the phases originated during this in-service period, several etchants were used in the structural study, together w...
Infrared and Mössbauer studies of iron in aluminosilicate glasses
Silva, M. G. Ferreira da; Costa, B. F. O.http://www.sciencedirect.com/science/article/B6TXM-447D4BH-2V/1/1cc307028183ecbe239e608e3d4a9db5
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