We report direct detection of the formation and subsequent breakup of a complex containing positively charged muonium ( Mu+) and a substitutional Zn(Ga) acceptor in heavily doped p-type GaAs:Zn. Mu+ diffuses above 200 K with a hop rate nu = nu(0)e(-E(nu)/k(B)T) where nu(0) = (7.7+/-2.0)x10(8) s(-1) and E(nu) = 0.15(4) eV. Above 350 K, it forms the complex with a trapping radius of 500+/-200 A. The Mu-Zn complex breaks up above 550 K with a dissociation energy of 0.88(7) eV and prefactor of (5+/-4)x10(12) s(-1). Above 750 K, the cyclic reaction Mu+<--> Mu0 takes place.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.87.216403 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Probing Radical Addition to 1-Phosphabutadienes by Employing Muonium as a "Light Isotope" of Hydrogen.
Chemistry
January 2024
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada.
Understanding free radical addition to multiple bonds is important to elucidating the mechanistic details of addition polymerization reactions, albeit the fleeting radical intermediates are very difficult to detect by conventional methodologies. Muon spin spectroscopy (μSR) is a highly sensitive method that can detect radical species at 10 spins (cf. EPR: 10 spins, NMR: 10 spins).
View Article and Find Full Text PDFMuon Spin Rotation/Resonance (μSR) for Studying Radical Reactivity of Unsaturated Organophosphorus Compounds.
Chemistry
September 2022
Department of Applied Chemistry, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1-H113 Ookayama, Meguro-ku, Tokyo, 152-8552, Japan.
The positive muon (μ ) can be regarded as a light isotope of proton and has been an important tool to study radical reactions of organic compounds. Recently, muons have been applied to produce short-lived paramagnetic species from the heavier unsaturated organic molecules including the p-block elements. This article overviews recent muon spin rotation/resonance (μSR) studies on the phosphorus analogs of alkenes, anthracenes, and cyclobutane-1,3-diyls together with the fundamentals of μSR.
View Article and Find Full Text PDFLocal Electronic Structure and Dynamics of Muon-Polaron Complexes in Fe_{2}O_{3}.
Phys Rev Lett
January 2021
Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
We perform detailed muon spin rotation (μSR) measurements in the classic antiferromagnet Fe_{2}O_{3} and explain the spectra by considering dynamic population and dissociation of charge-neutral muon-polaron complexes. We show that charge-neutral muon states in Fe_{2}O_{3}, despite lacking the signatures typical of charge-neutral muonium centers in nonmagnetic materials, have a significant impact on the measured μSR frequencies and relaxation rates. Our identification of such polaronic muon centers in Fe_{2}O_{3} suggests that isolated hydrogen (H) impurities form analogous complexes, and that H interstitials may be a source of charge carrier density in Fe_{2}O_{3}.
View Article and Find Full Text PDFFree Radicals Formed by H Atom Addition to Allenes as Determined by Muon Spin Spectroscopy.
J Phys Chem A
December 2020
Department of Chemistry and TRIUMF, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
Allyl and vinyl radicals are important intermediates in diverse areas of chemistry, ranging from combustion to synthesis. However, questions remain about the competitive formation of these radicals from allenes. Here, we present a study of prototypical allyl and vinyl radicals formed by H atom addition to allenes.
View Article and Find Full Text PDFFree Radical Chemistry of Phosphasilenes.
Angew Chem Int Ed Engl
September 2020
Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
Understanding the characteristics of radicals formed from silicon-containing heavy analogues of alkenes is of great importance for their application in radical polymerization. Steric and electronic substituent effects in compounds such as phosphasilenes not only stabilize the Si=P double bond, but also influence the structure and species of the formed radicals. Herein we report our first investigations of radicals derived from phosphasilenes with Mes, Tip, Dur, and NMe substituents on the P atom, using muon spin spectroscopy and DFT calculations.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!