Research output: Contribution to journal › Article › peer-review
Hydrothermal synthesis, phase formation and crystal chemistry of the pyrochlore/Bi2WO6 and pyrochlore/α–Fe2O3 composites in the Bi2O3–Fe2O3–WO3 system. / Lomakin, M. S.; Proskurina, O. V.; Danilovich, D. P.; Panchuk, V. V.; Semenov, V. G.; Gusarov, V. V.
In: Journal of Solid State Chemistry, Vol. 282, 121064, 02.2020.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Hydrothermal synthesis, phase formation and crystal chemistry of the pyrochlore/Bi2WO6 and pyrochlore/α–Fe2O3 composites in the Bi2O3–Fe2O3–WO3 system
AU - Lomakin, M. S.
AU - Proskurina, O. V.
AU - Danilovich, D. P.
AU - Panchuk, V. V.
AU - Semenov, V. G.
AU - Gusarov, V. V.
PY - 2020/2
Y1 - 2020/2
N2 - The present study was devoted to the investigation of the influence of the Bi/Fe ratio in precursors on the formation of heterogeneous systems with the pyrochlore composition Biy+0.67δFeyW2-yO6O'δ (hereinafter BFWO)/Bi2WO6, and BFWO/α-Fe2O3 under hydrothermal conditions at 200°С in a nitric acid solution within 6 h. It was shown that at the Bi/Fe ratios of ~1–9, the two coexisting phases are bismuth tungstate (Bi2WO6) with the crystallite size of about 7 nm, and BFWO with the crystallite size of about 30 nm, while at the Bi/Fe ratios of ~0.05–0.33, the coexisting phases are BFWO with the crystallite size of about 40 nm, α-Fe2O3 and the X-ray amorphous Fe2O3. According to the Mössbauer spectroscopy data, the position of iron in BFWO is described by two doublets with similar chemical shifts, which indicates the inhomogeneous distribution of iron in the tungsten sublattice. The results of the local energy dispersive X-ray microanalysis (EDXMA), in combination with the data on the BFWO structure refined by the Rietveld method, as well as the TEM microstructure data, have shown the obtaining of a new pyrochlore structure, that is, BFWO, which forms within a wide range of compositions. In accordance with the refined data on the BFWO structure, it was demonstrated that this phase has the displacively disordered pyrochlore structure, in which bismuth atoms occupy the 96g Wyckoff position (WP).
AB - The present study was devoted to the investigation of the influence of the Bi/Fe ratio in precursors on the formation of heterogeneous systems with the pyrochlore composition Biy+0.67δFeyW2-yO6O'δ (hereinafter BFWO)/Bi2WO6, and BFWO/α-Fe2O3 under hydrothermal conditions at 200°С in a nitric acid solution within 6 h. It was shown that at the Bi/Fe ratios of ~1–9, the two coexisting phases are bismuth tungstate (Bi2WO6) with the crystallite size of about 7 nm, and BFWO with the crystallite size of about 30 nm, while at the Bi/Fe ratios of ~0.05–0.33, the coexisting phases are BFWO with the crystallite size of about 40 nm, α-Fe2O3 and the X-ray amorphous Fe2O3. According to the Mössbauer spectroscopy data, the position of iron in BFWO is described by two doublets with similar chemical shifts, which indicates the inhomogeneous distribution of iron in the tungsten sublattice. The results of the local energy dispersive X-ray microanalysis (EDXMA), in combination with the data on the BFWO structure refined by the Rietveld method, as well as the TEM microstructure data, have shown the obtaining of a new pyrochlore structure, that is, BFWO, which forms within a wide range of compositions. In accordance with the refined data on the BFWO structure, it was demonstrated that this phase has the displacively disordered pyrochlore structure, in which bismuth atoms occupy the 96g Wyckoff position (WP).
KW - Crystal structure determination
KW - Crystallite size
KW - Hydrothermal synthesis
KW - Mössbauer spectroscopy
KW - Powder X-ray diffraction
KW - Pyrochlore
KW - PROPERTY
KW - OPTICAL-PROPERTIES
KW - BI2WO6
KW - MAGNESIUM
KW - CONDUCTIVITY
KW - DIELECTRIC-PROPERTIES
KW - Mossbauer spectroscopy
KW - NANOCRYSTALLITES
KW - MAGNETIC-PROPERTIES
KW - MOSSBAUER
KW - FE
UR - http://www.scopus.com/inward/record.url?scp=85078253835&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/94365c32-c9c0-3016-9d27-8ab62b5a74f8/
U2 - 10.1016/j.jssc.2019.121064
DO - 10.1016/j.jssc.2019.121064
M3 - Article
AN - SCOPUS:85078253835
VL - 282
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
M1 - 121064
ER -
ID: 51662028