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M. M. NYSHCHENKO, V. V. ANIKEYEV, E. A. TSAPKO, G. P. PRYKHOD’KO, and Yu. I. SEMENTSOV
«‘Capture’ of Positrons by Carbon Nanotubes in Polypro-pylene Based Composite»
769–776 (2009)
PACS numbers: 61.48.De, 61.72.Hh, 61.80.Fe, 71.60.+z, 78.70.Bj, 81.07.De, 82.30.Gg
Electronic properties of polypropylene (PP), carbon nanotubes (CNT) and PP–CNT composites within the concentration interval from 0 to 5 wt.% CNT are studied by the method of electron–positron annihilation. Prominent feature of angle-correlation spectra of annihilation radiation (ACAR) for PP-based composites is the presence in them of four components—narrow (NG), medial (MG), wide (WG) Gaussians, and the parabolic contribution (PC). NG is caused by annihilation of positrons from the bound hydrogen-like state—positronium. In pure PP, PC is not present, and ACAR is represented by superposition of three Gaussians. At 0.5 wt.% CNT in PP, PC appears in ACAR. Contribution of NG is observed in pure PP and PP–CNT composites (up to 3 wt.% CNT inclusively). The analysis of these results shows that, in the composites under investigation, the most part of positrons (up to 97%) annihilates in CNT; their electronic properties are essentially modified by PP surrounding.
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