Research output: Contribution to journal › Article › peer-review
Evolution of the Fe3+ Ion Local Environment During the Phase Transition ε-Fe2O3 → α-Fe2O3. / Yakushkin, S. S.; Balaev, D. A.; Dubrovskiy, A. A. et al.
In: Journal of Superconductivity and Novel Magnetism, Vol. 31, No. 4, 01.04.2018, p. 1209-1217.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Evolution of the Fe3+ Ion Local Environment During the Phase Transition ε-Fe2O3 → α-Fe2O3
AU - Yakushkin, S. S.
AU - Balaev, D. A.
AU - Dubrovskiy, A. A.
AU - Semenov, S. V.
AU - Shaikhutdinov, K. A.
AU - Kazakova, M. A.
AU - Bukhtiyarova, G. A.
AU - Martyanov, O. N.
AU - Bayukov, O. A.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Evolution of the local environment of Fe3+ ions in deposited Fe2O3/SiO2 nanoparticles formed in samples with different iron contents was investigated in order to establish the conditions for obtaining the stable ε-Fe2O3/SiO2 samples without impurities of other iron oxide polymorphs. Microstructure of the samples with an iron content of up to 16% is studied by high-resolution transmission electron microscopy, X-ray diffraction analysis, and Mössbauer spectroscopy, and their magnetic properties are examined. At iron concentrations below 6%, calcinations of iron-containing precursor nanoparticles in a silica gel matrix lead to the formation of the ε-Fe2O3 iron oxide polymorphic modification without foreign phase impurities, while at the iron concentration in the range of 6–12%, the hematite phase forms in the sample in the fraction of no more than 5%. It is concluded on the basis of the data obtained that the spatial stabilization of iron-containing particles is one of the main factors facilitating the formation of the ε-Fe2O3 phase in a silica gel matrix without other iron oxide polymorphs. It is demonstrated that the increase in the iron content leads to the formation of larger particles in the sample and gradual changes of the Fe3+ ion local environment during the phase transition ε-Fe2O3 → α-Fe2O3.
AB - Evolution of the local environment of Fe3+ ions in deposited Fe2O3/SiO2 nanoparticles formed in samples with different iron contents was investigated in order to establish the conditions for obtaining the stable ε-Fe2O3/SiO2 samples without impurities of other iron oxide polymorphs. Microstructure of the samples with an iron content of up to 16% is studied by high-resolution transmission electron microscopy, X-ray diffraction analysis, and Mössbauer spectroscopy, and their magnetic properties are examined. At iron concentrations below 6%, calcinations of iron-containing precursor nanoparticles in a silica gel matrix lead to the formation of the ε-Fe2O3 iron oxide polymorphic modification without foreign phase impurities, while at the iron concentration in the range of 6–12%, the hematite phase forms in the sample in the fraction of no more than 5%. It is concluded on the basis of the data obtained that the spatial stabilization of iron-containing particles is one of the main factors facilitating the formation of the ε-Fe2O3 phase in a silica gel matrix without other iron oxide polymorphs. It is demonstrated that the increase in the iron content leads to the formation of larger particles in the sample and gradual changes of the Fe3+ ion local environment during the phase transition ε-Fe2O3 → α-Fe2O3.
KW - Magnetic properties
KW - Mossbauer spectroscopy
KW - Phase transition
KW - Structure size effect
KW - ε−FeO iron oxide nanoparticles
KW - TRANSFORMATION
KW - SILICA-GEL
KW - FE2O3/SIO2
KW - PARTICLES
KW - NANOCRYSTALS
KW - IRON
KW - COERCIVE FIELD
KW - GAMMA-FE2O3
KW - NANOPARTICLES
KW - epsilon-Fe2O3 iron oxide nanoparticles
KW - MAGNETIC-PROPERTIES
UR - http://www.scopus.com/inward/record.url?scp=85028618531&partnerID=8YFLogxK
U2 - 10.1007/s10948-017-4307-y
DO - 10.1007/s10948-017-4307-y
M3 - Article
AN - SCOPUS:85028618531
VL - 31
SP - 1209
EP - 1217
JO - Journal of Superconductivity and Novel Magnetism
JF - Journal of Superconductivity and Novel Magnetism
SN - 1557-1939
IS - 4
ER -
ID: 9916459