ELECTRON PARAMAGNETIC RESONANCE

Omar Radwano.a.radwan@Gmail.com

201306050

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Yevgeny Zavoisky (1907 –1976)

1944(Kochelaev and Lablokov , 1995)

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CONTENTS EPR spectroscopy

Spectroscopy Paramagnetism Resonance▪ Zeeman effect▪ Hyperfine interaction

EPR instrumentation EPR spectrum Geological applications Advantages and disadvantages Conclusion

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EPR BASICS

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SPECTROSCOPY

(Weldon, 2009)

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PARAMAGNETISM

(Nesse, 2012)

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RESONANCE Zeeman effect

(Jonas, 1997)

E=hѵ=gβH

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RESONANCE Hyperfine interaction

(Jonas, 1997)

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RESONANCE

(Eaton GR et al., 2010)

2(I) +12(I) +1

2(I) +1

Hyperfine interaction

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EPR SPECTRUM

(Brustolon and Giamello, 2009)

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EPR - INSTRUMENTATIONspectrometer (Lund et al., 2011)

(Lund et al., 2011)

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EPR APPLICATIONS IN EARTH SCIENCES

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ESR ages from the Eupchon fault zone range from 2000 to 500ka.

The fault rocks were reactivated at least five times 2000, 1300, 900–1100, 700–800, and 500–600ka ago.

potentially active fault

potential seismic hazards to the nuclear power plant in its vicinity.

CASE 1: ESR dating of the Eupchon fault, South Korea

(Lee and Yang, 2007)

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Case 2: The use of electron spin resonance spectroscopy for determining the provenance of classical marbles

(Attanasio, 1999)

“The Mn2+ EPR spectra of marbles are similar for samples coming from the same quarry, and this property is used in archaeological studies in assessing the origin of ancient marbles”

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Case 3: EPR probes in sedimentary rocks: The features of Mn2+ and free radicals distribution in the Permian formation in Tatarstan

(Bulka, 1991)

Distribution of Mn+2 in the dolomites can reflect different thermodynamic parameters of the environment of dolomitizationused to characterize sedimentary beds, especially if they are unfossilferous

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Case 4: EPR of Radicals in Primitive Organic Matter: A Tool for the Search of Biosignatures of the Most Ancient Traces of Life

(Skrzypczak et al., 2008)

define four stages of maturation of the organic matter according to the evolution of g-factors, EPR intensity, peak-to-peak line width and line shapederive a relationship between the line shape and the age of the organic matter, valid for ages ranging from about 600 Myr to about 3500 Myr

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Case 5: Evidence of weathering stages of phyllosilicates from biotite/muscovite to kaolinite, probed by EPR spectroscopy

(Nicolini et al., 2009)

EPR studies show that the weathering from biotite to kaolinite, through muscovite, corresponds to varying the Fe(III) site symmetry;• from a residual rhombic structure in biotite, •to rhombic and axial symmetries in muscovite •until a rhombic and a more symmetrical site (but not yet totally axial as in muscovite) is obtained in kaolinite.

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ADVANTAGES AND DISADVANTAGES

Advantages Sample size required Time required Detection limit Oxidation state

Disadvantages Sensitivity towards paramagnetic

species Complicated spectra

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CONCLUSIONS

spectroscopic method for studies of paramagnetic species

Information provided: Direct evidence for presence of free electrons in a sample Type of sample Molecular structure and the environment near the electron Molecular motion

Applications Geochronology Geochemical studies Structure, Composition and origin of minerals

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ACKNOWLEDGEMENT

I owe a debt of gratitude to Prof. Dogan and Prof. Morsy for giving me the opportunity to learn this technique.

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REFERENCES Attanasio, D., 1999. The use of electron spin resonance spectroscopy for

determining the provenance of classical marbles. Appl. Magn. Reson. 16, 383–402.

Brustolon, M., Giamello, E., 2009. Electron Paramagnetic Resonance: A Practitioners Toolkit, 1 edition. ed. Wiley.

Bulka GR, Nizamutdinov NM, Mukhutdinova NG, Khasanova NM, Galeev AA, Vinokurov VM, 1991. EPR probes in sedimentary rocks: The features of Mn2+

and free radicals distribution in the Permian formation in Tatarstan. Appl Magn Reson.;2(1):107–15

Eaton GR et al., 2010. Quantitative EPR a Practitioners Guide. Springer-Verlag Vienna.

Kochelaev BI, IAblokov IV, 1995. The beginning of paramagnetic resonance. Singapore; River Edge, NJ: World Scientific.

Lee H-K, Yang J-S, 2007. ESR dating of the Eupchon fault, South Korea. Quaternary Geochronology.;2(1–4):392–7.

Nesse, W.D., 2012. Introduction to mineralogy. Oxford University Press, New York.

Weldon DG, 2009. Failure Analysis of Paints and Coatings. Revised Edition edition. Wiley.

Nicolini, K.P., Lombardi, K.C., Schreiner, W.H., Mazzaro, I., Wypych, F., Mangrich, A.S., 2009. Evidence of weathering stages of phyllosilicates from biotite/muscovite to kaolinite, probed by EPR spectroscopy. Miner Petrol 97, 139–144.

Skrzypczak-Bonduelle, A., Binet, L., Delpoux, O., Vezin, H., Derenne, S., Robert, F., Gourier, D., 2008. EPR of Radicals in Primitive Organic Matter: A Tool for the Search of Biosignatures of the Most Ancient Traces of Life. Appl Magn Reson 33, 371–397.

Lee, H.-K., Yang, J.-S., 2007. ESR dating of the Eupchon fault, South Korea. Quaternary Geochronology 2, 392–397.