Fabrication and spectroscopic properties of nanocrystalline La2Hf2O7:Pr

La2Hf2O7 nanopowders doped with different Pr concentrations (0.05-10 mol.%) were synthesized by the Pechini method. XRD measurements confirmed the single crystalline phase formed already at 800 degrees C and the structure was cubic pyrochlore. Luminescence excitation and emission as well as radioluminescence spectra were recorded for the materials. Both optical and X-ray excitation of La2Hf2O7:Pr produced a red emission resulting from the 4f-4f transitions of Pr3+ ions. Luminescence of materials synthesized at low temperatures was characterized by broadband glass-type emissions, while heat treatment at 1400 degrees C led to spectra showing the typical for crystalline hosts narrow and intense 4f-4f transitions of Pr3+. (C) 2010 Elsevier Ltd. All rights reserved.