Radiolabelling Measurements of Radicals Derived from Terpenoid Volatile Organic Conpounds (VOCs) Adsorbed in Porous Carbon

2006 ◽  
Vol 31 (3) ◽  
pp. 159-188 ◽  
Author(s):  
Christopher J. Rhodes
Keyword(s):  
Free Radicals ◽  
Porous Carbon ◽  
Muon Spin ◽  
Activation Parameters ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Longitudinal Field ◽  
Reorientational Motion ◽  
Volatile Organic

Radiolabelled free radicals were formed by the addition of muonium-a radioactive hydrogen atom with a positive muon as its nucleus-to α-pinene, β-pinene, dihydrocarvone, dihydrocarveol and dipentene, each as adsorbed in porous carbon. The radicals were identified using transverse-field muon spin rotation (TF-MuSR) and the activation parameters associated with their reorientational motion were measured using longitudinal-field muon spin relaxation (LF-MuSRx). Two distinct adsorbed fractions were detected in each sample, characterised by activation energies in the range 2-6 kJ/mol and 12-16 J/mol respectively.

Studies of Radio-Labelled Free Radicals Derived from a VOC (Volatile Organic Compound), Benzaldehyde, Adsorbed in Cation-Exchanged Zeolite X

2006 ◽  
Vol 31 (3) ◽  
pp. 139-158 ◽  
Author(s):  
Christopher J. Rhodes
Keyword(s):  
Activation Energy ◽  
Free Radicals ◽  
Muon Spin ◽  
Activation Parameters ◽  
Longitudinal Field ◽  
Zeolite X ◽  
Molecular Reorientation ◽  
Reorientational Motion ◽  
Major Species ◽  
Volatile Organic

Radio-labelled free radicals were formed by the addition of muonium-a radioactive hydrogen atom with a positive muon as its nucleus-to benzaldehyde, as adsorbed in cation-exchanged zeolite X. PhCHOMu• radicals were the major species formed and the activation parameters associated with their reorientational motion were measured using longitudinal-field muon spin relaxation (LF-MuSRx). Two distinct adsorbed fractions were detected in each of the samples containing Li+, Na+, K+, Ca2+, Sr2+ and Ba2+ cations, believed to be from (1) an effectively bulk benzaldehyde component with an almost common activation energy for molecular reorientation of ca 3kJ/mol, and (2) benzaldehyde adsorbed inside the zeolite supercages. MgX showed only the supercage fraction clearly.

Intramolecular Motion in Organic free Radicals Studied by Muon Spin Rotation and Level-Crossing Spectroscopy

1988 ◽  
pp. 155-156
Author(s):  
P. W. Percival ◽  
J. -C. Brodovitch ◽  
S. -K. Leung ◽  
D. Yu ◽  
R. F. Kiefl ◽  
...  
Keyword(s):  
Free Radicals ◽  
Muon Spin ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Level Crossing ◽  
Intramolecular Motion

scholarly journals Two-gap superconductivity in Lu2Fe3Si5: A transverse-field muon spin rotation study

2011 ◽  
Vol 83 (5) ◽  
Author(s):  
P. K. Biswas ◽  
G. Balakrishnan ◽  
D. McK. Paul ◽  
M. R. Lees ◽  
A. D. Hillier
Keyword(s):  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Rotation Study

scholarly journals Transverse field muon-spin rotation signature of the skyrmion-lattice phase inCu2OSeO3

2015 ◽  
Vol 91 (22) ◽  
Author(s):  
T. Lancaster ◽  
R. C. Williams ◽  
I. O. Thomas ◽  
F. Xiao ◽  
F. L. Pratt ◽  
...  
Keyword(s):  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation

scholarly journals Longitudinal Field Muon Spin Rotation Study of Magnetic Freezing in Fe Rich FeSe0.25Te0.75

2012 ◽  
Vol 30 ◽  
pp. 254-257
Author(s):  
W.A. MacFarlane ◽  
O. Ofer ◽  
K.H. Chow ◽  
M.D. Hossain ◽  
T.J. Parolin ◽  
...  
Keyword(s):  
Muon Spin ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Longitudinal Field ◽  
Rotation Study

Article

1999 ◽  
Vol 77 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Paul W Percival ◽  
Brenda Addison-Jones ◽  
Jean-Claude Brodovitch ◽  
Khashayar Ghandi ◽  
Joachim Schüth
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Carbon Skeleton ◽  
Muon Spin Rotation ◽  
Level Crossing ◽  
Hyperfine Constants ◽  
Planar Carbon

Muonium addition to pyrene has been investigated by means of transverse field muon spin rotation and muon level-crossing spectroscopy. Two hydropyrenyl radicals are produced and easily detected while a third is formed in low abundance. Muon and proton hyperfine constants were experimentally determined and compared with semiempirical and ab initio calculations. It is concluded that the radicals are of cyclohexadienyl type, i.e., the Mu adds only to carbon atoms that can assume a tetrahedral -CHMu- configuration without distorting the planar carbon skeleton of pyrene.Key words: muonium, pyrene, radical, hyperfine.

Germanium-centered free radicals studied by muon spin spectroscopy

2014 ◽  
Vol 92 (6) ◽  
pp. 508-513 ◽  
Author(s):  
Robert West ◽  
Kerim Samedov ◽  
Amitabha Mitra ◽  
Paul W. Percival ◽  
Jean-Claude Brodovitch ◽  
...  
Keyword(s):  
Free Radicals ◽  
Density Functional ◽  
Muon Spin ◽  
Coupling Reaction ◽  
Transverse Field ◽  
Coupling Constants ◽  
Muon Spin Rotation ◽  
Functional Theory ◽  
Hyperfine Constant ◽  
Germanium Compounds

Transverse-field muon spin rotation (TF-μSR) spectra have been recorded for free radicals formed by positive muon irradiation of nine different divalent germanium compounds. Muon-electron hyperfine coupling constants (Aμ) were determined from the spectra and compared with values predicted from density functional theory molecular orbital (DFT-MO) calculations on the muoniated radicals formed by muonium addition to the germanium atom. The muon hyperfine constants for germylenes containing N–Ge bonds are generally quite large, from 593 to 942 MHz, indicating strong interaction between the muon and the unpaired electron in these radicals. The radical derived from one of the germylenes exhibited a significantly lower muon hyperfine constant, suggesting that in this case the muoniated germyl radical undergoes a coupling reaction to form a digermanyl radical, which is what is detected by μSR.

scholarly journals On the Robustness of the MnSi Magnetic Structure Determined by Muon Spin Rotation

2018 ◽  
Vol 2 (3) ◽  
pp. 19 ◽  
Author(s):  
Pierre Dalmas de Réotier ◽  
Alain Yaouanc ◽  
Alex Amato ◽  
Alexander Maisuradze ◽  
Daniel Andreica ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Zero Field ◽  
Magnetic Structures ◽  
Wide Range ◽  
Distribution Parameters ◽  
Manganese Silicide

Muon spin rotation ( μ SR) spectra recorded for manganese silicide MnSi and interpreted in terms of a quantitative analysis constrained by symmetry arguments were recently published. The magnetic structures of MnSi in zero-field at low temperature and in the conical phase near the magnetic phase transition were shown to substantially deviate from the expected helical and conical structures. Here, we present material backing the previous results obtained in zero-field. First, from simulations of the field distributions experienced by the muons as a function of relevant parameters, we confirm the uniqueness of the initial interpretation and illustrate the remarkable complementarity of neutron scattering and μ SR for the MnSi magnetic structure determination. Second, we present the result of a μ SR experiment performed on MnSi crystallites grown in a Zn-flux and compare it with the previous data recorded with a crystal obtained from Czochralski pulling. We find the magnetic structure for the two types of crystals to be identical within experimental uncertainties. We finally address the question of a possible muon-induced effect by presenting transverse field μ SR spectra recorded in a wide range of temperature and field intensity. The field distribution parameters perfectly scale with the macroscopic magnetization, ruling out a muon-induced effect.

scholarly journals Transverse field muon-spin rotation measurement of the topological anomaly in a thin film of MnSi

2016 ◽  
Vol 93 (14) ◽  
Author(s):  
T. Lancaster ◽  
F. Xiao ◽  
Z. Salman ◽  
I. O. Thomas ◽  
S. J. Blundell ◽  
...  
Keyword(s):  
Thin Film ◽  
Muon Spin ◽  
Transverse Field ◽  
Spin Rotation ◽  
Muon Spin Rotation ◽  
Rotation Measurement
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