Sol-Gel Synthesis, Thermal Behavior of Nanopowders and Chemical Stability of La1 – xHoxPO4 Ceramic Matrices
- Authors: Mezentseva L.P.1, Osipov A.V.1, Ugolkov V.L.1, Akatov A.A.2, Doilnitsyn V.A.2, Maslennikova T.P.1, Yakovlev A.V.1
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Affiliations:
- Grebenshchikov Institute of Silicate Chemistry
- Saint-Petersburg State Institute of Technology (Technical University)
- Issue: Vol 44, No 5 (2018)
- Pages: 440-449
- Section: Article
- URL: https://journals.rcsi.science/1087-6596/article/view/216733
- DOI: https://doi.org/10.1134/S1087659618050127
- ID: 216733
Cite item
Abstract
Nanosized powders of orthophosphates in the LaPO4–HoPO4–H2O system have been synthesized to determine the mutual solubility of LaPO4 · nH2O and HoPO4 · nH2O initial components and to obtain ceramic matrices by sintering them. Formation of hexagonal, monoclinic or tetragonal solid solutions was revealed, and their limits and thermal stability were determined. A series of limited hexagonal LaPO4 · nH2O-based solid solutions was observed within the 0 ≤ x ≤ 0.6 concentration range up to 600°C. Further they transformed to monoclinic LaPO4-based form within the 0 ≤ x ≤ 0.3 concentration range. Solubility of LaPO4 · nH2O and LaPO4 in tetragonal HoPO4(· nH2O) is lower (≤10 mol %). Specific surface area of La1–xHoxPO4 · nH2O powders was in the range of 90.5–165.0 m2/g depending on x. Leaching rate of La3+ and Ho3+ from La1–xHoxPO4 matrices in nitric acid solution (pH 1–2) was determined to be 10–5–10–2 g/(cm2 day) for both ions.
About the authors
L. P. Mezentseva
Grebenshchikov Institute of Silicate Chemistry
Author for correspondence.
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 199034
A. V. Osipov
Grebenshchikov Institute of Silicate Chemistry
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 199034
V. L. Ugolkov
Grebenshchikov Institute of Silicate Chemistry
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 199034
A. A. Akatov
Saint-Petersburg State Institute of Technology (Technical University)
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 190013
V. A. Doilnitsyn
Saint-Petersburg State Institute of Technology (Technical University)
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 190013
T. P. Maslennikova
Grebenshchikov Institute of Silicate Chemistry
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 199034
A. V. Yakovlev
Grebenshchikov Institute of Silicate Chemistry
Email: la_mez@mail.ru
Russian Federation, St. Petersburg, 199034