Search

Your search keyword '"Vasconcellos, M.A.Z."' showing total 37 results
Start Over Author "Vasconcellos, M.A.Z."
37 results on '"Vasconcellos, M.A.Z."'

20. Structural and magnetic behavior of Ar+-implanted Co/Pd multilayers: interfacial mixing

Author

Schelp, L.F., Carara, M., Viegas, A.D.C., Vasconcellos, M.A.Z., and Schmidt, J.E.

Subjects
Thin films, Multilayered -- Research, X-rays -- Diffraction, Magnetization -- Analysis, Physics
Abstract

The structural and magnetic evolution of (111) Co/Pd multilayers submitted to Ar(super t) implantation are studied by XRD characterization and magnetization measurements. Controlled atomic mixing at the interfaces occurs due to low-dose and low-flux radiation. Ion implantation is an excellent technique to induce step-by-step modification in thin films. Small degrees of interfacial mixing influences room temperature saturation magnetization measurements.

Published
1994

37. Synthesis and characterization of Fe-Al2O3 composites

Author

Paesano Jr., A., Matsuda, C.K., da Cunha, J.B.M., Vasconcellos, M.A.Z., Hallouche, B., and Silva, S.L.

Subjects
*NANOPARTICLES, *COMPOSITE materials, *ALUMINUM oxide
Abstract

We have synthesized composites of the type Fex(Al2O3)100−x by arc-melting compacted pellets of iron and alumina powders with starting compositions of x=0.4, 2, 3, 5, 10, 20, 40 and 60. Aluminas of two different nominal grades (99.7% and 99.99%) were used in the preparation of the composites. The samples were characterized by X-ray diffractometry, magnetization and Mo¨ssbauer spectroscopy. The results revealed the formation of the spinel FeAl2O3+z (hercynite phase) and of metallic iron partially nanostructured by this melting process. The Mo¨ssbauer subspectral areas of the formed phases were plotted against x, showing that increasing the starting iron content of the mixed powders favors the hercynite reaction. It was also observed that when the more pure alumina is used for cast, more hercynite is formed or, alternatively, less iron nanocrystallites precipitate, when compared to the less pure oxide. An arc-melted sample (x=2) was annealed at 1200°C in a hydrogen atmosphere, revealing hercynite reduction and phase separation of metallic iron. [Copyright &y& Elsevier]

Published
2003
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results