کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10714055 | 1025568 | 2012 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Atomic fraction around defects associated with nanoparticles in Alî¸Cuî¸Mg alloys
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
A positron annihilation spectroscopy analysis method to obtain a quantitative determination of the chemical composition around defects inside nanoparticles is presented here. This methodology is applied to Alî¸Cuî¸Mg alloys to study the rapid hardening phenomena associated with solute-vacancy aggregation. Coincidence Doppler Broadening (CDB) and lifetime spectroscopy measurements of reference samples of pure elements with and without defects were analyzed to give quantitative information of the average chemical environment around vacancies, i.e. the atomic fraction of the first neighbors of these defects, in the alloys studied. The accuracy and reproducibility of the methodology is confirmed not only by good fits to the experimental data but, in most cases, by the consistency between the mean lifetime values predicted, using the CDB estimation, and the mean lifetime values independently measured. Discrepancies in the methodology are expected when there is poor CDB contrast between elements, i.e. having similar electronic structure (for example, Al and Mg). The criterion for establishing the statistical accuracy of the separation of elements in these special cases is discussed. The methodology can be applied not only to study homogeneous materials as metallic alloys, but also to study the depth profile in thin films.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 407, Issue 14, 15 July 2012, Pages 2676-2683
Journal: Physica B: Condensed Matter - Volume 407, Issue 14, 15 July 2012, Pages 2676-2683
نویسندگان
Rafael Ferragut,