Details
| Original language | English |
|---|---|
| Pages (from-to) | 323-331 |
| Number of pages | 9 |
| Journal | Journal of Colloid and Interface Science |
| Volume | 321 |
| Issue number | 2 |
| Publication status | Published - 14 Mar 2008 |
| Externally published | Yes |
Abstract
Three samples of calcite homogeneously doped with Eu3+ were synthesized in a mixed-flow reactor. By means of selective excitation of the 5D0 → 7F0 transition at low temperatures (T < 20 K), three different Eu3+ species (species A, B, and C, respectively) could be discriminated. For each one, the emission spectrum and lifetime were obtained after selective excitation of the single species. On the basis of these data, species C could be identified as Eu3+ incorporated into the calcite lattice on the (nearly) octahedral Ca2+ site. Species B was also identified as Eu3+ incorporated into the calcite lattice, but the ligand field shows a much weaker symmetry. Species A, however, is not incorporated into the crystal's bulk, having 1-2 H2O ligands left in its first coordination sphere and showing very little symmetry, and is considered as Eu3+ adsorbed onto the calcite surface. The emission spectra of species C for Eu:calcite grown in the presence of Na+ were found to differ from those of Eu:calcite synthesized in the presence of K+. The latter revealed a strong distortion in site symmetry, which was not observed in the samples grown in Na+ solutions. This finding provides spectroscopic evidence in favor of an incorporation mechanism based on the charge-balanced coupled substitution of Na+ + Eu3 + ↔ 2 Ca2 +.
Keywords
- Calcite, Charge compensation, Incorporation, Lanthanides/actinides, TRLFS
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Biomaterials
- Materials Science(all)
- Surfaces, Coatings and Films
- Chemical Engineering(all)
- Colloid and Surface Chemistry
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In: Journal of Colloid and Interface Science, Vol. 321, No. 2, 14.03.2008, p. 323-331.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Site-selective time-resolved laser fluorescence spectroscopy of Eu3+ in calcite
AU - Marques Fernandes, M.
AU - Schmidt, M
AU - Stumpf, Thorsten
AU - Walther, Clemens
AU - Bosbach, Dirk
AU - Klenze, R.
AU - Fanghänel, Thomas
PY - 2008/3/14
Y1 - 2008/3/14
N2 - Three samples of calcite homogeneously doped with Eu3+ were synthesized in a mixed-flow reactor. By means of selective excitation of the 5D0 → 7F0 transition at low temperatures (T < 20 K), three different Eu3+ species (species A, B, and C, respectively) could be discriminated. For each one, the emission spectrum and lifetime were obtained after selective excitation of the single species. On the basis of these data, species C could be identified as Eu3+ incorporated into the calcite lattice on the (nearly) octahedral Ca2+ site. Species B was also identified as Eu3+ incorporated into the calcite lattice, but the ligand field shows a much weaker symmetry. Species A, however, is not incorporated into the crystal's bulk, having 1-2 H2O ligands left in its first coordination sphere and showing very little symmetry, and is considered as Eu3+ adsorbed onto the calcite surface. The emission spectra of species C for Eu:calcite grown in the presence of Na+ were found to differ from those of Eu:calcite synthesized in the presence of K+. The latter revealed a strong distortion in site symmetry, which was not observed in the samples grown in Na+ solutions. This finding provides spectroscopic evidence in favor of an incorporation mechanism based on the charge-balanced coupled substitution of Na+ + Eu3 + ↔ 2 Ca2 +.
AB - Three samples of calcite homogeneously doped with Eu3+ were synthesized in a mixed-flow reactor. By means of selective excitation of the 5D0 → 7F0 transition at low temperatures (T < 20 K), three different Eu3+ species (species A, B, and C, respectively) could be discriminated. For each one, the emission spectrum and lifetime were obtained after selective excitation of the single species. On the basis of these data, species C could be identified as Eu3+ incorporated into the calcite lattice on the (nearly) octahedral Ca2+ site. Species B was also identified as Eu3+ incorporated into the calcite lattice, but the ligand field shows a much weaker symmetry. Species A, however, is not incorporated into the crystal's bulk, having 1-2 H2O ligands left in its first coordination sphere and showing very little symmetry, and is considered as Eu3+ adsorbed onto the calcite surface. The emission spectra of species C for Eu:calcite grown in the presence of Na+ were found to differ from those of Eu:calcite synthesized in the presence of K+. The latter revealed a strong distortion in site symmetry, which was not observed in the samples grown in Na+ solutions. This finding provides spectroscopic evidence in favor of an incorporation mechanism based on the charge-balanced coupled substitution of Na+ + Eu3 + ↔ 2 Ca2 +.
KW - Calcite
KW - Charge compensation
KW - Incorporation
KW - Lanthanides/actinides
KW - TRLFS
UR - http://www.scopus.com/inward/record.url?scp=41649114200&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2008.01.017
DO - 10.1016/j.jcis.2008.01.017
M3 - Article
AN - SCOPUS:41649114200
VL - 321
SP - 323
EP - 331
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
SN - 0021-9797
IS - 2
ER -