Finely-dispersed phosphors of Y2O3:Eu and Y3Al5O12:Eu have been synthesized with the help of Pechini method and the method of self-propagating high-temperature synthesis (SHS). During the synthesis of phosphors on the basis of Y2O3 carried out with Pechini method the size of crystallites increases with the enlargement of concentration of yttrium, but it decreases when the method of SHS is applied. The structure of phosphors on the basis of Y3Al5O12 (YAG) is strongly amorphized. This fact agrees with the data of XRD and with the prevalence of the band with λmax = 613 nm in the spectra of this phosphor. The enlargement of yttrium concentration in it promotes the amorphisation of yttrium aluminum garnet and the decrease of a crystal phase content. The sample of Y3Al5O12:Eu synthesized with Pechini method has the maximum intensity, while in conditions of excitement with “high-level” X-ray radiation which corresponds to the radiation of industrial medical X-ray apparatus, the phosphor of Y2O3:Eu synthesized with the help of SHS showed the largest intensity. Colloid solutions prepared with the use of the samples synthesized by SHS method revealed a higher steadiness and a lower disposition to the sedimentation process. The samples of Y2O3:Eu phosphor possessing the smallest size of particles and the highest intensity of X-ray luminescence are the most suitable for the creation of pharmacological drugs used for photodynamic therapy.

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A series of finely dispersed Y

A series of highly efficient Y2O3:Eu cathodoluminescent phosphors with submicron particle size is synthesized using either Pechnini process or self propagating high temperature synthesis. This approach provides the extension of application areas for such phosphors to some conditions where larger particles obtained by conventional co-precipitation technique cannot be used.

Nanomaterials find permanently extending applications in various areas of life. In particular, nanosized phosphors can be used as pharmaceutical carriers capable of emitting ultraviolet or visible light that activates a photosensitizer, thus significantly expanding the possibilities of photodynamic therapy in the treatment of oncological, bacterial and viral diseases. The conditions required for the use of nanosized phosphors in medicine include their fine dispersion and effective luminescence in the red region of visible light spectrum upon stimulation by X-ray radiation of the range accepted for medical applications, particularly for diagnostic and therapeutic purposes in many diseases. The aim of this work was to study the effect of microwave treatment of Y2O3:Eu phosphors prepared by hydrothermal synthesis in ethylene glycol at 230 °C for 6 hours, involving the decomposition of mixed acetate. In order to reduce the aggregation and growth of the resulting particles, Aerosil A300 with average particle size 7 nm was added to the reaction mixture in the course of hydrothermal synthesis in the ratio 1:1 relating to the obtained phosphor. The microwave treatment was carried out at 800 °C for 5 minutes. The developed method provided Y2O3:Eu phosphor samples featuring with increased luminescence intensity in the region 610…700 nm compared to similar phosphors earlier prepared using the rapid thermal annealing (RTA) procedure.