Dulina N. Multifunctional materials based on rare earth oxide nanopowders R2O3 (R = Lu, Y)

Thesis is devoted to the development of the preparation technology of new monodisperse weakly agglomerated powders of two types: (1) isometric single-crystal nanoparticles Lu2O3, (Lu0,95Eu0,05)2O3, (2) spherical particles of mesoporous Y2O3, (Y1-xRx)2O3 (R-La, Eu , Nd) for composite and ceramic materials based on them. Rare earth metal oxides (REMO) nanopowders obtained by the method precipitation from solutions including synthesis of precursor with subsequent low temperature crystallization (T=600-1100 C). Using complex methods of thermal analysis, X-ray diffraction, infrared spectroscopy, electron microscopy, we investigated effect of phase and chemical composition of precursor on structural and morphological properties of nanopowders REMO. In the work established technology for preparation of composites "matrix Y2O3/ filler ZnO" with diameter of 70-400 nm (size distribution 15%) and matrix distribution of the filler. Methods of electron microscopy, X-ray diffraction and optical spectroscopy revealed that the interval of thermal stability of ZnO phase in the pores Y2O3 is 600-700 C, which corresponds to a high degree of stoichiometry of anionic sublattice of zinc oxide in an excess of oxygen. Obtained by vacuum sintering optical (Lu0,95Eu0,05)2O3 ceramics with a relative density of 99 ± 1%, the average grain size of about 51 microns and coefficient of linear 50% optical transmission in the wavelength range 500-1100 nm. Found that Eu3+ ions act as sintering solid impurities in the synthesis of Lu2O3 ceramics and speeds up sinterig by increasing the mobility of the cation diffusion.