کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8039428 1518607 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Free-volume characterization of nanostructurized substances by positron annihilation lifetime spectroscopy
ترجمه فارسی عنوان
بررسی حجم آزاد مواد نانوساختار شده توسط طیف سنجی طول عمر نابودی پوزیترون
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سطوح، پوشش‌ها و فیلم‌ها
چکیده انگلیسی
Methodological possibilities of positron annihilation lifetime (PAL) spectroscopy are examined to parameterize free-volume structural evolution processes in some nanostructurized substances obeying conversion from positronium (Ps) decaying to positron trapping. Unlike conventional x3-term fitting analysis based on admixed positron trapping and Ps decaying, the effect of nanostructurization is considered as occurring due to conversion from preferential Ps decaying in initial host matrix to positron trapping in modified (nanostructurized) host-guest matrix. The developed approach referred to as x3-x2-CDA (coupling decomposition algorithm) allows estimation defect-free bulk and defect-specific positron lifetimes of free-volume elements responsible for nanostructurization. The applicability of this approach is proved for some nanostructurized materials allowing free-volume changes through Ps-to-positron trapping conversion, such as (i) metallic Ag nanoparticles embedded in polymer matrix, (ii) structure-modification processes caused by swift heavy ions irradiation in polystyrene, and (iii) host-guest chemistry problems like water immersion in alumomagnesium spinel ceramics. This approach is considered to be used as test-indicator, separating processes of host-matrix nanostructurization due to embedded nanoparticles from uncorrelated changes in positron-trapping and Ps-decaying channels.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 416, 1 February 2018, Pages 102-109
نویسندگان
, , ,