XPS and ToF‐SIMS characterization of a Finemet surface: effect of heating |
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Authors: | S P Chenakin G G Galstyan A B Tolstogouzov N Kruse |
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Institution: | 1. Institute of Metal Physics, NASU, Blvd. Akad. Vernadsky 36, 03680 Kiev‐142, Ukraine;2. Dipartimento di Chimica, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy;3. Université Libre de Bruxelles (ULB), Chimie‐Physique des Matériaux, CP243, Campus Plaine, B‐1050 Bruxelles, Belgium |
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Abstract: | X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) were used to study the surface composition and electronic structure of Finemet, Fe73Si15.8B7.2Cu1Nb3, in the original amorphous state and after gradual heating in vacuum to a temperature of 400 °C and cooling back to room temperature. It was found that relaxation processes occurring during heat treatment well below the crystallization onset caused the physico‐chemical state of Finemet surface to change irreversibly. In the relaxed alloy, the surface originally covered with the native air‐formed oxide was significantly enriched with elemental iron and depleted of other alloy constituents compared with the original state. Yet in the as‐quenched state, clustering of copper atoms on the Finemet surface was detected which was enhanced by heating. The thermal treatment resulted in the selective reduction of iron oxides and caused noticeable changes in the valence band structure and the Fe L3VV Auger spectrum associated with atomic redistribution. Copyright © 2009 John Wiley & Sons, Ltd. |
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Keywords: | amorphous alloy XPS valence band ToF‐SIMS annealing segregation |
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