Registration Number
0221U100643,
0119U100025
, R & D reports
Title
Polyoxometalates, orthovanadates and oxyorthosilicates of transition metals and lanthanides for creation of new materials
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Head
Rozantsev Georgiy M., Доктор хімічних наук
Registration Date
08-01-2021
Organization
Vasyl' Stus Donetsk National University
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The energies of mixing (interaction parameters) and temperature ranges of stability of solid solutions Lu1–xLnxVO4 (where Ln is a rare-earth element (REE), scandium, or yttrium) with the zircon structure were calculated using the crystal-energy theory of isomorphous miscibility. It was shown that, with increasing atomic number of REE in the Ce–Lu series, the calculated energies of mixing and critical decomposition temperatures of the solid solutions regularly decrease. The substitution limits at various T, the thermodynamic phase stability, and the T of transition to a metastable state were determined. The thermodynamic stability diagram of the REE vanadate solid solutions Lu1 – xLnxVO4 was presented. The results of the work can be used for searching the compositions of matrices and activators of new laser and other materials.
The conditions for the synthesis of novel praseodymium(III)-containing salt, Na9[Pr(W5O18)2]∙34.25H2O, with heteropoly tungstate anion were determined. By the methods of chemical analysis, FT-IR, and FT-Raman spectroscopy it was shown that sodium heteropoly decatungstopraseodymate(III) Na9[Pr(W5O18)2]∙34.25H2O was precipitated from Na2WO4 solution under Z=ν(H+)/ν(WO42–)=0.80 after adding of acetone. By FT-IR and FT-Raman spectroscopy, the heteropoly anion is shown to belong to the Peacock–Weakley structural type. By the method of SEM it was shown that the grain size of Na9[Pr(W5O18)2]∙34.25H2O is within the range of 200–450 nm. Homogeneity of the obtained phase was confirmed by the uniform contrast of the surface in the BEC mode. An X-ray single crystal analysis was carried out and crystal structure for Na9[Pr(W5O18)2]∙34.25H2O (a=18.272(5), b=18.512(5), c=20.865(6), α=113.60(3), β=97.79(3), γ=90.36(3), V=6393(3) Å3, Z= 2, triclinic, P-1) was determined. It was established that no polytungstate structures of this type (both the unit cell parameters and the composition and packing within the structure) are described in the literature.
Product Description
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Baumer Viacheslav M.
Get'man Evgen I.
Gumerova Nadiia I.
Duvanova Ella S.
Mariichak Oleksandra Yu.
Oleksii Yuliia A.
Popovska Olena Yu.
Radio Serhii V.
Rumiantseva Zhanna O.
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2021-03-17
