Search academic texts

Information × Registration Number 0222U005449, 0122U000854 , R & D reports Title Regularities of the effect of the composition and conditions of synthesis on the luminescent properties of Eu (II) in halide and oxohalide compounds and systems - promising materials for detectors and transformers of UV radiation popup.stage_title Head Zinchenko Viktor F., Доктор хімічних наук Registration Date 30-12-2022 Organization Physico-Chemical Institute O. Bogatsky National Academy of Sciences of Ukraine popup.description2  The nature of the interaction in the NaCl-KCl-CeF3-EuF3 system was determined by the method of diffuse reflectance spectroscopy. The influence of the composition and preliminary solid-phase heat treatment on the nature of the interaction of the system with the NaCl-KCl melt was revealed. It is shown that the content of Eu(II) increases and the content of Eu(III) decreases due to oxidation-reduction reactions between the components of the systems both at the solid-phase reaction and during interaction with the salt melt. The dominant role of Eu2+ ions in the salt melt is particularly clearly manifested in the diffuse reflectance spectra by the presence of intense absorption bands and negative absorption in the UV range. High-intensity luminescence of Eu2+ ions was detected, which significantly exceeds that of Eu3+ ions. The ratio between the components has a certain influence on the luminescence intensity of Eu2+ and Eu3+ ions. It is shown that the change in the excitation wavelength has an ambiguous effect on the luminescence intensity of Eu2+ ions, the maximum of which occurs at 350 nm. The lifetime of the excited states of Eu2+ and Eu3+ ions, which is of the order of μs and ms, respectively, was estimated. The mechanism of formation of EuF2 and EuF3 fluoride nanoparticles in solidified salt melts and the role of protective shells made of EuCl2–4 complex ions in melt luminescence processes are proposed. Calcium chlorborates, Ca2BO3Cl activated by Eu2+ and Ce3+ ions were synthesized by means of solid-phase reactions - promising materials for night mode safety signs. It is shown that the control of the reducing medium during the synthesis process and the limitation of contact with atmospheric air during sample storage are important conditions for obtaining luminescent materials based on Ca2BO3Cl:Eu2+. Product Description popup.authors Ieriomin Oleg G. Efryushina Ninel P. Berezovska Iryna V. Volchak Ganna V. Doha Pavlo G. Dotsenko Volodymyr P. Zseltvai Ivan І. Zinchenko Viktor F. Korovin Oleksandr Yu. Kucher Albert O. Magunov Igor R. Rusakova Nataliia V. Sadkovska Liudmyla V. Semenishyn Mykola M. Smola Serhii S. Stamikosto Olena V. Stoianova Iryna V. Tesluk Olga І. Khomenko Olena V. Chivireva Natalia О. popup.nrat_date 2022-12-30 Close