Monoclinic Gd(1-x)Eu(x)BO(3) nanopowders were successfully synthesized using a modified Pechini method. The crystal structure of the prepared materials was revised and confirmed using several techniques such as: IR, XRD, TEM, Raman spectroscopy and EDX analysis. The obtained material was comprised of particles, consisting of parts with the average size 350 nm. The luminescence properties of the prepared phosphors with different concentrations of Eu(3+) ions were characterized by excitation and emission spectra and its kinetic decay. The Judd-Ofelt parameters (Ω(2), Ω(4)), quantum efficiency, η, and chromaticity coordinates were also calculated.

Nanocrystalline REF3:Tb3+ fluorides (where RE = Y, La, Ce, Gd, and Yb) have been synthesized using a precipitation method in a water/glycerine system. Glycerine, which was added in 25% by volume to Ln(NO3)3 and NH4F reactant solutions, prevented an uncontrolled growth of the nanocrystals and enhanced the stability of the colloids formed in water. X-ray analysis and transmission electron microscopy confirmed the formation of the fluoride nanocrystals. Additionally, the presence of glycerine on the surface of the crystallites was established on the basis of IR measurements. The use of Tb3+ ions resulted in a green luminescence of the products, with a maximum of this emission at 545 nm. Spectroscopic analysis was performed to investigate the effects of the fluoride matrix on the luminescent properties of the Tb3+ ions. Quantum yields were also determined. In particular, the most efficient system, based on CeF3 doped with 15% Tb3+, was investigated in detail.

New interesting aspects of the spectroscopic properties, magnetism, and method of synthesis of gadolinium orthovanadates doped with Eu(3+) ions are discussed. Gd(1-x)Eu(x)VO4 (x = 0, 0.05, 0.2) bifunctional luminescent materials with complex magnetic properties were synthesized by a microwave-assisted hydrothermal method. Products were formed in situ without previous precipitation. The crystal structures and morphologies of the obtained nanomaterials were analyzed by X-ray diffraction and transmission and scanning electron microscopy. Crystallographic data were analyzed using Rietveld refinement. The products obtained were nanocrystalline with average grain sizes of 70-80 nm. The qualitative and quantitative elemental composition as well as mapping of the nanocrystals was proved using energy-dispersive X-ray spectroscopy. The spectroscopic properties of red-emitting nanophosphors were characterized by their excitation and emission spectra and luminescence decays. Magnetic measurements were performed by means of vibrating sample magnetometry. GdVO4 and Gd0.8Eu0.2VO4 exhibited paramagnetic behavior with a weak influence of antiferromagnetic couplings between rare-earth ions. In the substituted sample, an additional magnetic contribution connected with the population of low-lying excited states of europium was observed.