A study of Eu-doped La2Zr2O7 nanocrystals prepared by salt-assistant combustion synthesis

Nanocrystalline (La1−xEux)2Zr2O7 series solid solutions were prepared by a simple and controllable salt-assisted combustion process. The samples were characterized by XRD, TEM and EDS. The results showed the partial substituted products were single-phase solid solutions. The effect of thermal treatment temperature on the crystal size of nanocrystals and the activation energy of crystal growth during calcinations were studied. And the activation energy of (La1−xEux)2Zr2O7 series with x = 0.05, 0.1, 0.25, 0.5, and 0.75 was 25.4, 27.8, 28.0, 32.4, and 30.6 kJ/mol, respectively. TEM images revealed that the products were composed of well-dispersed cubic-like particles with the range of size at 20–50 nm. EDS results furtherly confirmed that the composition of the obtained compound was in agreement with the stiochiometric formular. The emission spectra of (La1−xEux)2Zr2O7 nanocrystals at 385 nm upon excitation showed that there were some intense and prevailing emission peaks located at 590–650 nm.

► Thermal treatment temperatures have an important effect on the crystal size of nanocrystals.
► The activation energy of crystal growth during calcinations was studied.
► (La1−xEux)2Zr2O7 series of nanocrystals showed strong fluorescence activity.
► With the increasing of the Eu-doped amount, concentration quenching appears.