Preparation and luminescence properties of Eu3+ incorporated in CaCO3 nanocrystals with multiple sites

Eu3+ has been successfully incorporated in multisites of cubic CaCO3 nanocrystals via carbonation method. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflection spectra (DRS) and photoluminescence (PL) spectroscopy were utilized to characterize the properties of all samples. PL spectra show that the intensity of CaCO3:0.02Eu3+ nanoparticle is different when Eu3+ is introduced at different growth stages of CaCO3. The different PL intensity is attributed to the different sites of Eu3+ located in CaCO3 nanocrystals, which was identified by the analysis of Judd-Ofelt parameters, site-selective spectroscopy and decay curves. One site of Eu3+ at disordered site near the surface is analogous to Eu3+ located in a glasslike environment. The other site is located at the inner lattice associated with an ordered crystalline environment.