Propriedades estruturais e fotofísicas da hidroxiapatita dopada com íons lantanídeos

ABSTRACT

Hydroxyapatite (HAp) matrices doped with lanthanide ions Eu³⁺, Ce³⁺ and Gd³⁺, [Ca_10-xLn_x(PO₄)₆(OH)₂] were obtained through the precipitation method so their photophysical properties could be studied. From the Scanning Electron Microscopy analyzes it was observed that samples doped with lanthanide ions (Ln³⁺) showed similarity with the morphology of pure HAp, whereas Rietveld-refined X-ray diffractograms showed that the matrix appears as the major phase (≈70%) while (≈30%) of a second phase of tricalcium phosphate (TCP) was due to the different doping levels. Adsorption isotherms obtained by the BET technique indicated that all the synthesized materials are classified as mesoporous. The emission spectra of the materials exhibit bands typical of the Ln³⁺ ions incorporated into the matrix structure at 573 nm (⁵D₀→F₀), 600 nm (⁵D₀→F₁), 628 nm (⁵D₀→F₂), and 698 nm (⁵D₀ → F₄) for HAp/Eu, 337-360 nm (5d → 4f) for HAp/Ce and at 425 nm for HAp/Gd.

Keywords
Hydroxyapatite; Composite; Luminescent; Biomaterial; Properties