Naslov
A study of shells of some biological species by electron paramegnetic resonance and X-ray diffraction

Autori
Nothig-Laslo, Vesna ; Medaković, Davorin ; Gržeta, Biserka ; Plazonić, Miljenka ; Popović, Stanko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
International Conference "From Solid State to BioPhysics" / - Zagreb, 2002, 22-22

Skup
International Conference "From Solid State to BioPhysics"

Mjesto i datum
Cavtat, Hrvatska, 13.06.2002. - 19.06.2002

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Condensed matter physics; Sea shells; Sea Urchins; EPR; XRD

Sažetak
Calcite in shells of some sea biological species contains a fraction of Mn2+ as a paramagnetic substitute for Ca2+. EPR spectroscopy of Mn2+ ions provides their immediate environment. This fact was used in the study of the shell structure of mussels Mytilus galloprovincialis (Adriatic sea) and of sea urchins Sterechinus neumayeri (Antarctica). EPR results were compared with those obtained by XRD. The studied mussel shells were pink instead of white, due to pollution. XRD showed that pink shells contained aragonite and calcite (with broadened diffraction lines) like white shells, but the fraction of calcite was smaller in the pink shells. EPR confirmed that the fraction of calcite was smaller in the pink than white shells, and showed that neighbours of Mn2+ had a lower symetry in the pink shells. The sea urchin skeletons contained magnesian calcite, with different fractions of Mg2+ in various parts of the skeleton. A nonlinear relation between the lengths of unitcell parameters and the Mg2+ fraction in magnesian calcite was found. EPR gave additional data to explain observed varieties.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Geologija, Biologija

POVEZANOST RADA