Radiation-Induced Defects in Carbonate Minerals: EPR Study

1. Radiation-Induced Defects
in Carbonate Minerals: EPR Study
Omar Atef Radwan
g201306050
1
– MSE 501 –
Term Paper

2. OUTLINE
1. Introduction
Carbonate minerals
Radiation induced defects RID
2. Methodology
Electron Paramagnetic Resonance EPR
EPR parameters of RID in carbonate minerals
3. Applications
2

3. CARBONATE MINERALS
3
Mackenzie and Lerman, 2006
 CO3
2- anionic group
 four groups:
o calcite group
odolomite group
oaragonite group
ohydrated carbonate group
 Carbonate rocks:
o limestone
o Dolostone
o Marble
calcite [CaCO3] dolomite [CaMg(CO3)2]

4. RADIATION INDUCED DEFECTS
• Any defect represents a local deficit of charge neutrality
• Anion vacancy:
– lack of negative charge
– entering a cation with a greater positive charge
structure position: positively charged (an electron trap)
• Cation vacancy:
– Lack of positive charge
– inserting a cation with lesser positive charge
structure position: negatively charged (a hole trap)
• Ex: in carbonate minerals, the radical CO3
2- becomes a free radical:
– a hole-captured radical CO3
-
– an electron-captured radical CO3
3-.
4

5. RADIATION INDUCED DEFECTS
• An insulating mineral has two energy levels,
at which electrons may occur:
The lower energy level (valence band) is
separated from the higher energy level
(conduction band) by a so-called forbidden
zone.
• Ionizing radiation emitted from radioactive
elements (U, Th, and K) knocks off negatively
charged electrons from atoms. The electrons
are transferred to the conduction band and
positively charged holes are left behind near
the valence band.
• Some electrons can be trapped by impurities
(electron traps) in the crystal lattice. 5
Grün, 2008

6. RADIATION INDUCED DEFECTS
• When a mineral is formed:
All electrons are in the ground state.
• After its formation:
The mineral is exposed to natural
radiation leading to the trapping of
electrons and holes
• The concentration of these centers in a
given sample is a measure of the total
radiation dose to which the sample was
exposed
• These electrons can be directly measured
by electron paramagnetic resonance
spectroscopy 6
Grün, 2008

7. ELECTRON PARAMAGNETIC RESONANCE
• a.k.a: ESR
• spectroscopic method used to detect paramagnetic species.
• EPR spectrum: identification of paramagnetic species, their
concentration, molecular structure
7
Brustolon and Giamello, 2009

8. Paramagnetic species such as radiation induced defects are
present in carbonate minerals.
Hole center are formed in calcite by cation substitution:
Ca2+ is replaced by Mn2+, Fe3+, and Gd3+
Electron centers in calcite is due to anion substitution:
CO3
2- is replaced by the free radicals PO3
2-, PO3
0, PO2
2-,
PO2
0, AsO3
2-, AsO2
2-, SO3
-, BO2
0,CO3
3-, CO3
- and CO2
-
In dolomites the Mn2+ ion is a natural substitutional impurity
at the sites of both Ca2+ and Mg2+ ions.
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RID IN CARBONATE MINERALS

9. EPR PARAMETERS OF RID IN CARBONATE MINERALS
• Most widely used EPR signals
in carbonate minerals are
arising from the extrinsic
SO2
− and SO3
− and intrinsic
CO2
− and CO3
− which are the
radiation-induced defects.
o gA= 2.0057 (SO2
−)
o gB= 2.0036 (SO3
−)
o gC= 2.0007 (CO2
−)
o gD= 1.9973 (CO2
−)
9
Ulusoy et al., 2014

10. APPLICATIONS
• DATING
• PALEOTHERMOMETRY
• PROVENANCE OF MARBLE
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11. DATING
11
Equivalent Dose Determination
actual EPR part of the dating
procedure
Dose Rate Determination
calculated from the analysis of the
radioactive elements (mainly Th, U,
and K) in the sample and its
surroundings
𝐄𝐏𝐑 𝐚𝐠𝐞 𝐓 =
𝐚𝐜𝐜𝐮𝐦𝐮𝐥𝐚𝐭𝐞𝐝 𝐩𝐚𝐥𝐞𝐨𝐝𝐨𝐬𝐞 𝐆𝐲
𝐫𝐚𝐝𝐢𝐚𝐭𝐢𝐨𝐧 𝐫𝐚𝐭𝐞
𝐆𝐲
𝐲𝐞𝐚𝐫
=
𝐞𝐪𝐮𝐢𝐯𝐚𝐥𝐞𝐧𝐭 𝐝𝐨𝐬𝐞 [𝐃𝐄]
𝐚𝐯𝐞𝐫𝐚𝐠𝐞 𝐚𝐧𝐧𝐮𝐚𝐥 𝐝𝐨𝐬𝐞 𝐫𝐚𝐭𝐞 [𝐃]
Grün, 2008

12. PALEOTHERMOMETRY
• EPR peak at g = 2.0023 is due to
radiation damage
• The intensity of this peak is
related to the distance of the
sample from the intrusive contact
• Laboratory annealing experiments
on both the natural samples and
on artificially irradiated samples
(X-ray) have shown that the
signal decreases to a constant
value at a particular temperature
• signal therefore provides a
paleothermometer
12
Lloyd and Lumsden, 1987

13. PROVENANCE OF MARBLE
• Marble characterization
• distribution of Mn+2 between the crystallographically inequivalent
calcium and magnesium sites can be determined using EPR.
• occupation ratio
(K)=Mn2+ at Mg2+ site/Mn2+ at Ca2+ site
• Statistical treatment of these EPR data, has led to the selection of
parameters that are useful for quarry discrimination.
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14. 14

15. 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. 539p.
• Callens, F., Vanhaelewyn, G., Matthys, P., Boesman, E., 1998. EPR of
carbonate derived radicals: Applications in dosimetry, dating and
detection of irradiated food. Appl. Magn. Reson. 14, 235–254.
• Fantong, E.B., Takeuchi, A., Doke, R., 2013. Electron Spin Resonance (ESR)
Dating of Calcareous Fault Gouge of the Ushikubi Fault, Central Japan.
Appl Magn Reson 44, 1105–1123.
• Franco, R.W.A., Pelegrini, F., Rossi, A.M., 2003. Identification and valuation
of paramagnetic radicals in natural dolomites as an indicator of
geological events. Phys Chem Minerals 30, 39–43.
• Grün, R., 2008. ELECTRON SPIN RESONANCE DATING, in: Pearsall, D.M.
(Ed.), Encyclopedia of Archaeology. Academic Press, New York, pp. 1120–
1128.
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16. REFERENCES
• Mackenzie, F.T., Lerman, A., 2006. Mineralogy, Chemistry, and Reaction Kinetics of
the Major Carbonate Phases, in: Carbon in the Geobiosphere — Earth’s Outer
Shell —, TOPICS IN GEOBIOLOGY. Springer Netherlands, pp. 89–121.
• Marfunin, A.S., 1979. Spectroscopy, Luminescence and Radiation Centers in
Minerals. Springer Berlin Heidelberg, Berlin, Heidelberg.
• Molodkov, A., 1988. ESR dating of quaternary shells: Recent advances. Quaternary
Science Reviews 7, 477–484.
• Nesse, W.D., 2012. Introduction To Mineralogy. Oxford University Press, New York.
• Paul J. Angiolillo, N.G., 2008. Characterization, stability, and origin of natural
radiation-induced defects in the biogenic calcite of Belemnitella americana from
the Upper Cretaceous: An electron paramagnetic resonance study. Radiation
Physics and Chemistry 545–552.
• Ulusoy, Ü., Anbar, G., Bayarı, S., Uysal, T., n.d. ESR and 230Th/234U dating of
speleothems from Aladağlar Mountain Range (AMR) in Turkey. Quaternary
Research.
• Lloyd, R.V., Lumsden, D.N., 1987. The influence of temperature on the radiation
damage line in ESR spectra of metamorphic dolomites: A potential
paleothermometer. Chemical Geology 64, 103–108.
• Lloyd, R.V., Smith, P.W., Haskell, H.W., 1985. Evaluation of the Manganese Esr
Method of Marble Characterization. Archaeometry 27, 108–116.
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