Naslov
An EPR study of Cd2+ incorporation in vaterite

Autori
Noethig-Laslo, Vesna ; Brečević, Ljerka

Izvornik
Physical chemistry chemical physics (1463-9076) 1 (1999), 15; 3697-3700

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
calcium carbonate; vaterite; electron paramagnetic resonance (EPR) spectroscopy; cadmium

Sažetak
13C-vaterite, the unstable calcium carbonate polymorph, doped with Cd2+ was g-irradiated and the stable paramagnetic centres were studied using electron paramagnetic resonance (EPR) spectroscopy. The 13C isotope has nuclear spin (I = 1/2) and as a consequence the hyperfine interaction with the unpaired electron occurs. This revealed all paramagnetic centres of carbonate origin, i.e. ˙CO3- and ˙CO2- free radicals. Two paramagnetic centres induced by cadmium doped to vaterite, one characterized by ga = 1.9939 and the other by gb = 1.9886, were not split by the 13C-hyperfine splitting. Therefore, these paramagnetic centres are most probably due to CdO-. The locations of these paramagnetic centres in vaterite are determined and the role of cadmium in the formation of calcite crystals in the vaterite-precipitating system is discussed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA