Title | Preferential site occupancy of Eu(3+) ions in strontium hydroxyapatite nanocrystalline - Sr10(PO4)6(OH)2 - structural and spectroscopic characterisation. |
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Authors | Zawisza, K.; Wiglusz, R.J. |
Journal | Dalton Trans |
DOI | 10.1039/c6dt04731a |
Abstract |
Strontium hydroxyapatite (Sr10(PO4)6(OH)2) nanopowders doped with Eu(3+) ions were synthesized via a microwave-stimulated hydrothermal method and were heat-treated in the temperature range of 450-650 °C for 3 h. The concentration of Eu(3+) ions was set in the range of 0.5-5 mol% to investigate the site occupancy preference. The structural and morphological properties of the obtained samples were determined via XRD (X-ray powder diffraction) and TEM (transmission electron microscopy) techniques, as well as IR (infrared) and Raman spectroscopy. Nanoparticles were obtained in the range of 35-85 nm as a function of dopant concentration and sintering temperature. The luminescence properties of Eu(3+) ion-doped Sr10(PO4)6(OH)2, depending on dopant concentration and sintering temperature, were investigated. The Eu(3+) ion occupied one site (C3 (Sr1)) of Sr(2+) cations in the Sr10(PO4)6(OH)2 matrix, providing only one emission site, as results from luminescence spectroscopy data confirmed by the Rietveld refinement. A weak broad emission was observed with a peak at about 425 nm, corresponding to the 4f(6)5d(1) → 4f(7) ((8)S7/2) transition of Eu(2+) ions. The simplified Judd-Ofelt (J-O) theory was performed and a detailed analysis in connection with observed structural and spectroscopic measurements was carried out and has been described herein. |
Preferential site occupancy of Eu(3+) ions in strontium hydroxyapatite nanocrystalline - Sr10(PO4)6(OH)2 - structural and spectroscopic characterisation.