General properties of the paramagnetic centre at g = 2.0006 in carbonates

Investigation of lime mortars and plasters from archaeological excavations in Hippos (Israel) using Electron Paramagnetic Resonance

“…Sample 61H, which is the fraction 63-80 µm of a mortar, gives the EPR spectrum least affected by the presence of the triplet signal, presumably because the component that the signal was originating from was almost completely eliminated during sieving. Spectra of 61H exhibits the signals at g = 2.0034, 2.0013 and 1.9971 attributed to CO 2 -species; the peaks at 2.0034 and 2.0013 may be also interpreted as the axial CO 3 3-paramagnetic centre (Barabas, 1992;Barabas et al, 1992;Ikeya, 1993 and2004;Callens et al, 1998;Wencka and Krzyminiewski, 2004). Other peaks can be observed at g = 2.0424, 2.0209, 2.0156, 2.0102, 2.0082, 2.0057 and 2.0048.…”

Dose estimation, kinetics and dating of fossil marine mollusc shells from northwestern part of Turkey

“…During irradiation, conditions of charge particle equilibrium were maintained. Irradiated samples were kept at 100°C for 1 h for eliminate the contribution of unstable paramagnetic centers as recommended in the literature (Barabas et al, 1992a(Barabas et al, , 1992bEngin et al, 2006). All ESR measurements were carried out with a Bruker X band spectrometer (e-scan dosimeter reader) at ambient temperature under the following conditions.…”

“…In recent years, Electron Spin Resonance (ESR) technique has also been used for dating Quaternary fossils of mammals, human remains and shells of both marine and terrestrial molluscs (Molodkov, 1988; Barabas et al, 1992aBarabas et al, , 1992bMolodkov, 1993;Radtke, 1997, 1999;Engin et al, 2006;Kinoshita et al, 2006, Kerber et al, 2011. This technique is useful for Quaternary fossils because it can determine ages older than the maximum limit of 14 C (about 50,000 years) its upper limit is dependent on the saturation of defects and signal stability in older samples and on the thermal stability of the defects (Ikeya and Ohmura, 1981;Radtke et al, 1985;Shimokawa et al, 1992; Ikeya, 1993; Schellmann and Radtke , 1997;Lopes et al, 2013).…”

Thermal behaviour of ESR signals observed in various natural carbonates

“…Five signais are often présent in natural carbonates: g=2.0057 (called h-1 by Yokoyama et al, 1981); g=2.0031 (or £.L=2.0036 and g||=2.0021)(fc, Ikeya and Ohmura, 1981);g=2.0018 (g-3, Molodkov, 1988);g=2.0006 (h-3, Yokoyama et al, 1981); g= 1.9972 (g^=2.0030, gzz=2.0015, £^=1.9972) (A-complex, Barabas et al, 1992a). The thermal behaviour of thèse five lines are studied in this work.…”