Metastable states of laser synthesized oxide nanoparticles

Oxide nanopowders Y 2O 3, Nd 3+:Y 2O 3, Nd 3+:Y 2O 3 + Sc 2O 3, Al 2O 3, Nd 3+:Y 2O 3 + Al 2O 3, ZrO 2 were prepared with the help of pulse-repetitive CO 2 laser evaporation and subsequent vapor condensation in the flow of buffer gas. The mean size of the nanoparticles was about 10 nm. All these nanoparticles were found to be in metastable state at room temperature. Structure of the nanoparticles, the results of X-ray, thermogravimetry and differential scanning calorimetry (TG–DSC) analysis, as well as reasons of metastable lattice formation are discussed.