Study of Interaction Mechanism between Positrons and Ag Clusters in Dilute Al–Ag Alloys at Low Temperature |
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| Authors: | Xiaoshuang Liu Peng Zhang Baoyi Wang Xingzhong Cao Shuoxue Jin Runsheng Yu |
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| Affiliation: | 1.Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; (X.L.); (P.Z.); (B.W.); (X.C.); (S.J.);2.School of Nuclear Science and Technology, Chinese Academy of Sciences, Beijing 100039, China |
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| Abstract: | The microstructural evolution of dilute Al–Ag alloys in its early aging stage and at low temperatures ranging from 15 K to 300 K was studied by the combined use of Positron annihilation lifetime spectroscopy (PALS), high resolution transmission electron microscopy (HRTEM), and positron annihilation Coincidence Doppler broadening (CDB) techniques. It is shown that at low temperatures below 200 K, an Ag–vacancy complex is formed in the quenched alloy, and above 200 K, it decomposes into Ag clusters and monovacancies. Experimental and calculation results indicate that Ag clusters in Al–Ag alloys can act as shallow trapping sites, and the positron trapping rate is considerably enhanced by a decreasing measurement temperature. |
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| Keywords: | Al– Ag alloys, Ag clusters, positron annihilation, monovacancies, shallow trapping |
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