Publication: Aragonite to calcite transformation studies by esr of Mn2+ ions in sinotaia ingallsiana
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Issued Date
2009
Resource Type
File Type
application/pdf
ISSN
2179849
Other identifier(s)
2-s2.0-65349174461
Rights Holder(s)
มหาวิทยาลัยศรีนครินทรวิโรฒ
Bibliographic Citation
Modern Physics Letters B. Vol 23, No.9 (2009), p.1243-1247
Suggested Citation
Udomkan N., Limsuwan P. Aragonite to calcite transformation studies by esr of Mn2+ ions in sinotaia ingallsiana. Modern Physics Letters B. Vol 23, No.9 (2009), p.1243-1247. doi:10.1142/S0217984909019375 Retrieved from: https://hdl.handle.net/20.500.14740/7058
Author(s)
Abstract
We have studied paramagnetic Mn2+ ions present in the freshwater snail, Sinotaia ingallsiana (FS), Viviparus which are abundant in Thailand. The FS shells in our study were ground into fine powder. A set of seven samples was each then separately annealed for 2 hours in air atmosphere at 300°C, 400°C, 500°C, 600°C, 700°C, 800°C and 900°C, respectively. Our detailed ESR spectral analyses of FS show that Mn2+ ions enter Ca2+ sites during a biomineralization process. The hyperfine coupling constant (A) and zero-field splitting (D) in the ESR spectrum of Mn2+ in calcite and aragonite were determined. The spreading of the non-central allowed transitions was analyzed and the experimental transitions were attributed. For calculating the hyperfine coupling constant, five methods for calculating the zero-field splitting, based on the analysis of the allowed and forbidden transitions, were provided. The values of the hyperfine coupling constant range from 87.50 to 89.00 G and those of the zero-field splitting range from 110.00 to 116.00 G. © 2009 World Scientific Publishing Company.