Publication
623
Appl. Surf. Sci. 254, 1022-1026, 2007.
DOI:
:10.1016/j.apsusc.2007.08.001
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Excitation of high energy levels under laser exposure of suspensions of nanoparticules in liquids |
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G.A. Shafeev, A.V. Simakin, F. Bozon-Verduraz, M. Robert
Wave Research Center of A.M. Prokhorov General Physics Institute, 38, Vavilov Street, 119991 Moscow, Russian Federation
ITODYS, UMR CNRS 7086, Université Paris 7-Denis Diderot, 2, place Jussieu, 75251 Paris cedex 05, France
Laboratoire d'Electrochimie Moléculaire, Unité Mixte de Recherche Université, CNRS No 7591, Université de Paris 7-Denis Diderot, 2 place Jussieu, 75251 Paris Cedex 05, France
Laser exposure of suspensions of nanoparticles in liquids leads to excitation of high energy levels in both liquid and nanoparticle material. The emission spectrum of the colloidal solution under exposure of a suspension metallic nanoparticles in water to radiation of a Nd:YAG laser of a picosecond range of pulse duration is discussed. Excitation of nuclear energy levels and neutron release is experimentally studied on the model system of transmutation of Hg into Au that occurs under exposure of Hg nanodrops suspended in D2O. The proposed mechanism involves: (i) emission of X-ray photons by Hg nanoparticles upon laser exposure, leading to neutron release from D2O, (ii) initiation of Hg ? Au transmutation by the capture of neutrons. The effect of transmutation is more pronounced using 196 Hg isotope instead of Hg of natural isotope composition. The influence of laser pulse duration on the degree of transmutation (from fs through ns range) is discussed. . |