scholarly journals The ENDOR Spectrum of 1,7,7-Trimethylbicyclo[2.2.1]heptane-2,3-dione Semiquinone in Solution

1980 ◽  
Vol 53 (6) ◽  
pp. 1747-1748 ◽  
Author(s):  
Reiko Tosa ◽  
Yashige Kotake ◽  
Masaharu Okazaki ◽  
Hideo Shikata ◽  
Keiji Kuwata
Keyword(s):  
Endor Spectrum

The first ENDOR spectrum of naked metal clusters: 7Li3, 6Li 7Li2 and 7Li3(H2O)x in an adamantane matrix

1996 ◽  
Vol 263 (5) ◽  
pp. 710-714 ◽  
Author(s):  
Brynmor Mile ◽  
Philip D. Sillman ◽  
Abdul R. Yacob
Keyword(s):  
Metal Clusters ◽  
Endor Spectrum

Einfluß von Kohärenzeffekten auf die Linienformen im ENDOR-Spektrum des Perinaphthenyl-Radikals / Influence of Coherence Effects On Line Shapes in the ENDOR Spectrum of the Perinaphthenyl Radical

1973 ◽  
Vol 28 (7) ◽  
pp. 1069-1080 ◽  
Author(s):  
K.-P. Dinse
Keyword(s):  
Free Radicals ◽  
Satisfactory Agreement ◽  
High Power ◽  
Endor Spectrum ◽  
Relaxation Times ◽  
Neutral Radical ◽  
Endor Line ◽  
Line Shapes ◽  
Coherence Effects ◽  
On Line

A cw high-power ENDOR spectrometer is described. Freed's theory of coherence effects on ENDOR line shapes of free radicals in solution was tested with cw NMR fields up to 30 Gauss. The neutral radical Perinaphthenyl (PNT) with groups of three and six equivalent protons served as example. A satisfactory agreement with the theory was found, even in quantitative terms. Very reasonable values for relaxation times T1e , T2e and T1n of the PNT could be determined by fitting Te-1/We, Wn/We and using measured values for BMW, BNMR and the EPR line width.

scholarly journals ENDOR SPECTRUM AND WAVEFUNCTION FOR THE RELAXED-EXCITED STATE OF THE F CENTER IN KBr

1973 ◽  
Vol 34 (C9) ◽  
pp. C9-141-C9-144 ◽  
Author(s):  
G. BALDACCHINI ◽  
L. F. MOLLENAUER
Keyword(s):  
Excited State ◽  
Endor Spectrum ◽  
F Center

Electron nuclear double resonance of the F centre in CaF 2

1967 ◽  
Vol 301 (1466) ◽  
pp. 313-326 ◽  
Keyword(s):  
Point Defects ◽  
Alkaline Earth ◽  
Endor Spectrum ◽  
Double Resonance ◽  
Private Communication ◽  
Electron Nuclear Double Resonance ◽  
Colour Centres ◽  
Precise Information ◽  
Hyperfine Constants ◽  
Considerable Body

Although a considerable body of work exists on colour centres in the alkaline earth fluorides, precise information on the structure of intrinsic point defects in these crystals is meagre. Arends (1964) reported an e. p. r. spectrum in additively coloured CaF 2 which he assigned to the F centre. We have carried out endor measurements on additively coloured CaF 2 which confirm that the e. p. r. spectrum described by Arends is indeed due to the F centre. We have measured the hyperfine interaction of the F centre electron with the nuclei of the first four fluorine shells centred on the F centre and we compare our results with preliminary calcula­tions of the hyperfine constants by A. M. Stoneham (private communication). The effects of fluorine-fluorine interaction on the endor spectrum of the first shell fluorines are investigated in detail.

Endor spectrum of the VLi center in MgO at 4.2°K

1974 ◽  
Vol 15 (2) ◽  
pp. 399-402 ◽  
Author(s):  
G. Rius ◽  
A. Herve
Keyword(s):  
Endor Spectrum

Paramagnetic resonance and electron nuclear double resonance of substitutional hydrogen atoms in CaF 2

1967 ◽  
Vol 297 (1450) ◽  
pp. 376-396 ◽  
Keyword(s):  
Room Temperature ◽  
Endor Spectrum ◽  
Hyperfine Interactions ◽  
Double Resonance ◽  
Hydrogen Atoms ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Infrared Measurements ◽  
X Irradiation ◽  
Induced Defects

Recent infrared measurements have shown that hydrogen dissolves in CaF 2 as H - ions in fluorine sites (Elliott, Hayes, Jones, MacDonald & Sennett 1965). X-irradiation of CaF 2 : H crystals at room temperature produces paramagnetic hydrogen atoms in interstitial sites (Hall & Schumacher 1962). The present work shows that X-irradiation of CaF 2 : H crystals at 77°K produces hydrogen atoms in fluorine sites. These substitutional hydrogen atoms move into interstitial sites at 135°K giving rise to the e. p. r. spectrum observed by Hall & Schumacher in room temperature irradiated crystals. The present paper contains a detailed description of the e. p. r. and endor spectrum of the substitutional atoms in CaF 2 . It is found that the hyperfine interactions with second shell fluorines are smaller than with third and fourth shell fluorines and an explanation is suggested for this effect. Endor measurements of first shell fluorines show a resolved structure due to indirect fluorine-fluorine interactions. The endor measurements are of interest in connexion with the production and annealing mechanisms of the irradiation-induced defects.

Light-induced defect creation processes and light-induced defects in hydrogenated amorphous silicon

2020 ◽  
Vol 90 (2) ◽  
pp. 20101
Author(s):  
Kazuo Morigaki
Keyword(s):  
Endor Spectrum ◽  
Double Resonance ◽  
Low Frequency ◽  
Dipolar Interaction ◽  
Dangling Bond ◽  
Electron Nuclear Double Resonance ◽  
Defect Creation ◽  
The Matrix ◽  
Type Contact ◽  
Induced Defects

We have proposed a model of light-induced defect creation processes and light-induced defects. Recently, important results using pulsed electron-nuclear double resonance (ENDOR) by Fehr et al. [M. Fehr, A. Schnegg, C. Teutloff, R. Bittl, O. Astakhov, F. Finger, B. Rech, K. Lips, Phys. Status Solidi A 207, 552 (2010)] have been reported, so that these results are interpreted on the basis of our model. Fehr et al. have observed ENDOR signals due to hydrogen nuclei distributed around a dangling bond. The ENDOR spectra due to hydrogen nuclei being located with distance of r from the dangling bond have been calculated, taking into accounts the dipolar interaction, and also the Fermi-type contact hyperfine interaction for the H-related dangling bond (HDB) that is a dangling bond having hydrogen at a nearby site. The typical features of the observed ENDOR spectra are that the spectrum has a shoulder at the low frequency side from the natural NMR frequency of hydrogen and it has a dip in the central part. The calculated ENDOR spectrum of HDB exhibits such a shoulder. This is consistent with our model of light-induced defects such as HDB. The ENDOR spectra with various values of r are calculated. In this paper, we also deal with the distant ENDOR precisely, using the theory of distant ENDOR by Lambe et al. [J. Lambe, N. Laurance, K.C. McIrvine, R.W. Terhune, Phys. Rev. 122, 1161 (1961)]. The calculated distant ENDOR spectrum shows a dip in the central part. Concerning the dip, Fehr et al. attribute the dip to be due to the suppression of the matrix ENDOR line (this is called the artifact). Thus, it is not obvious whether the dip is due to such an artifact or the central part of the distant ENDOR spectrum.

The ENDOR spectrum of bis(p-methoxyphenyl)nitroxide

1971 ◽  
Vol 20 (3) ◽  
pp. 569-571 ◽  
Author(s):  
Robert D. Allendoerfer ◽  
John H. Engelmann
Keyword(s):  
Endor Spectrum
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