Journal ArticleDOI
A new model of positronium formation: Resonant positronium formation
Zhicheng Zhang,Yasuo Ito +1 more
TLDR
In this paper, a new model of positronium (Ps) formation is proposed, where the first stage is the inelastic collisions of e+ through formation of an intermediate state (M*e+) by resonant energy absorption and e+ attachment.Abstract:
‘‘Resonant model,’’ a new model of positronium (Ps) formation is proposed. The first stage of Ps formation is the inelastic collisions of e+ through formation of an intermediate state (M*.e+) by resonant energy absorption and e+ attachment. The second stage of Ps formation involves thermalized e+ and loosely bound electrons (excess electrons, excited molecules, and certain anions) through resonant electron transfer. Experimental results are reviewed from the viewpoint of the new model comparing it with the older models, the Ore model and the spur model.read more
Citations
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Journal ArticleDOI
Intra-spur positronic processes
TL;DR: In this article, it is suggested that the epithemal process has to be mixed up with the spur process in order to overcome the apparent inconsistency between the two processes in this way.
Journal ArticleDOI
Positronium formation in aqueous solutions of surfactant substances
TL;DR: In this paper, it is shown that the decrease of I ortho and positronium formation probability P Ps is a result of the space segregation of quasifree electrons (e - ) and positrons at the end part of its track containing micelles.
Journal ArticleDOI
Evidence of the participation of electronic excited states in the mechanism of positronium formation in substitutional Tb1−xEux(dpm)3 solid solutions studied by optical and positron annihilation spectroscopies
F. Fulgêncio,F.C. de Oliveira,F.C. de Oliveira,Dario Windmöller,Hermi F. Brito,Oscar L. Malta,G.F. de Sá,W.F. Magalhães,José C. Machado +8 more
TL;DR: A strong linear correlation between the (5)D(4) Tb(iii) energy level excited state lifetime and the positronium formation probability has been observed, indicating that the ligand-to-metal charge transfer LMCT states act in both luminescence quenching and positronia formation inhibition, as previously proposed.
Journal ArticleDOI
Luminescence and positron spectroscopies studies of tris(2,2,6,6-tetramethyl-3,5-heptanedionate) europium(III) and terbium(III) complexes containing 2-pyrrolidone as coligand
Alex S. Borges,F. Fulgêncio,Jeferson G. Da Silva,Tatiana A. Ribeiro-Santos,Renata Diniz,Dario Windmöller,W.F. Magalhães,Maria Helena Araujo +7 more
TL;DR: In this paper, the synthesis, characterization, luminescent properties and positronium formation yields of europium and terbium(III) complexes of stoichiometric formula Ln(dpm)3(2-pyr), where: Ln = Eu and Tb, dpm = 2,2,6,6-tetramethyl-3,5-heptanedionato (dipivaloylmethanate) ion, a β-diketonate ligand, and 2 pyr = γ-l
Journal ArticleDOI
Solid Eu(III) complexes studied by positron annihilation, optical and Mössbauer spectroscopies: insights on the positronium formation mechanism.
F. Fulgêncio,F.C. de Oliveira,F.C. de Oliveira,F.F. Ivashita,A. Paesano,Dario Windmöller,A. Marques-Netto,W.F. Magalhães,José C. Machado +8 more
TL;DR: Strong evidences that the electronic delocalization does not occur at both temperatures are found and suggest that the absence of positronium in Eu(III) complexes cannot be explained by a ligand/metal charge transfer process.
References
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Book
Positron and Positronium Chemistry
David M. Schrader,Y. C. Jean +1 more
TL;DR: Y.C. Jean and D.M. Schrader as mentioned in this paper proposed the slow Positron as a probe of surface chemistry. But their approach was limited to the detection of phase transition and other structural changes.
Book
Atomic and Molecular Radiation Physics
TL;DR: The atomic and molecular radiation physics is what we surely mean as discussed by the authors, no matter how you got the sentences that have been read from the books, surely they will give you goodness. But, we will show you one of recommendation of the book that you need to read.
Journal ArticleDOI
Spur reaction model of positronium formation
TL;DR: In this article, a new model of positronium (Ps) formation is proposed, which is based on a reaction between a positron and an electron in the positron spur.
Journal ArticleDOI
Further studies of the spur process of positronium formation in mixtures of organic liquids
P. Jansen,O.E. Mogensen +1 more
TL;DR: In this paper, positron lifetime studies were made of the following binary organic mixtures: (a) carbondisulphide mixtures with n -tetradecane, n -hexane, isooctane, neopentane, and tetramethylsilane (TMS); (b) neopsentane mixtures of methanol, ethanol, cyclohexanol, and methylcyclohexane; (c) cis-2-butene/trans-2butene, and benzene/ethanol.