Synthesis of NaYF4:Yb, Er up-conversion luminophore from nitrate flux

Abstract

The behavior of nanoparticle ensembles was studied using of NaRF 4 hexagonal phases. The evolution of particles in the process of rapid and productive synthesis from flux as a result of a chemical reaction was investigated. A low-temperature synthesis process in the medium of sodium nitrate was used. Synthesis of the samples of up-conversion phosphor NaY 0.78 Yb 0.2 Er 0.02 F 4 was performed from rare-earth nitrates at 350-430 • C for 15-500 min. NaF was used as the fluorinating agent. Powder X-ray phase analysis and scanning electron microscopy revealed a rapid transformation of the cubic alpha modification into a hexagonal phase, followed by the transformation of nanoparticles into hexagonal prisms of micron sizes. The up-conversion luminescence energy yield increased as the reaction time increased.

Novel Fluoride Matrix for Dual-Range Optical Sensors and Visualization

“…Fluoride matrices such as NaYF 4 [26], NaGdF 4 [27], and MF 2 , where M = Ca, Sr, Ba [28], have proven to be effective photonics materials [29]. It is known that an increase in matrix molecular weight leads to a decrease in multi-phonon relaxation and usually increases the luminescence energy yield [30,31].…”