Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 7209-7217 |
| Seitenumfang | 9 |
| Fachzeitschrift | Journal of Physical Chemistry C |
| Jahrgang | 115 |
| Ausgabenummer | 15 |
| Frühes Online-Datum | 24 März 2011 |
| Publikationsstatus | Veröffentlicht - 21 Apr. 2011 |
Abstract
A one-step synthesis of nanostructured bismuth ferrite (BiFeO3) via mechanochemical processing of a α-Fe2O3/Bi 2O3 mixture at room temperature is reported. The mechanically induced phase evolution of the mixture is followed by XRD and 57Fe Mössbauer spectroscopy. It is shown that the mechanosynthesis of the rhombohedrally distorted perovskite BiFeO3 phase is completed after 12 h. Compared to the traditional synthesis route, the mechanochemical process used here represents a one-step, high-yield, low-temperature, and low-cost procedure for the synthesis of BiFeO3. High-resolution TEM and XRD studies reveal a nonuniform structure of mechanosynthesized BiFeO3 nanoparticles consisting of a crystalline core surrounded by an amorphous surface shell. The latter is found to exhibit an extraordinarily high metastability causing a rapid crystallization of nanoparticles under irradiation with electrons. In situ high-resolution TEM observations of the crystallization clearly show that the heterogeneous processes of nucleation and growth of bismuth iron oxide crystallites are spatially confined to the amorphous surface regions. This fact provides access to the elucidation of the mechanism of mechanosynthesis. It is demonstrated that the mechanosynthesized ferrite nanoparticles exhibit a partial superparamagnetism at room temperature. Quantitative information on the short-range structure and hyperfine interactions, provided by the nuclear spectroscopic technique, is complemented by an investigation of the magnetic behavior of nanostructured BiFeO3 on a macroscopic scale by means of SQUID technique. As a consequence of canted spins in the surface shell of nanoparticles, the mechanosynthesized BiFeO3 exhibits an enhanced magnetization, an enhanced coercivity, and a shifted hysteresis loop.
ASJC Scopus Sachgebiete
- Werkstoffwissenschaften (insg.)
- Elektronische, optische und magnetische Materialien
- Energie (insg.)
- Allgemeine Energie
- Chemie (insg.)
- Physikalische und Theoretische Chemie
- Werkstoffwissenschaften (insg.)
- Oberflächen, Beschichtungen und Folien
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in: Journal of Physical Chemistry C, Jahrgang 115, Nr. 15, 21.04.2011, S. 7209-7217.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Mechanosynthesized BiFeO3 nanoparticles with highly reactive surface and enhanced magnetization
AU - Da Silva, Klebson L.
AU - Menzel, Dirk
AU - Feldhoff, Armin
AU - Kübel, Christian
AU - Bruns, Michael
AU - Paesano, Andrea
AU - Düvel, Andre
AU - Wilkening, Martin
AU - Ghafari, Mohammad
AU - Hahn, Horst
AU - Litterst, Fred J.
AU - Heitjans, Paul
AU - Becker, Klaus D.
AU - Šepelák, Vladimir
PY - 2011/4/21
Y1 - 2011/4/21
N2 - A one-step synthesis of nanostructured bismuth ferrite (BiFeO3) via mechanochemical processing of a α-Fe2O3/Bi 2O3 mixture at room temperature is reported. The mechanically induced phase evolution of the mixture is followed by XRD and 57Fe Mössbauer spectroscopy. It is shown that the mechanosynthesis of the rhombohedrally distorted perovskite BiFeO3 phase is completed after 12 h. Compared to the traditional synthesis route, the mechanochemical process used here represents a one-step, high-yield, low-temperature, and low-cost procedure for the synthesis of BiFeO3. High-resolution TEM and XRD studies reveal a nonuniform structure of mechanosynthesized BiFeO3 nanoparticles consisting of a crystalline core surrounded by an amorphous surface shell. The latter is found to exhibit an extraordinarily high metastability causing a rapid crystallization of nanoparticles under irradiation with electrons. In situ high-resolution TEM observations of the crystallization clearly show that the heterogeneous processes of nucleation and growth of bismuth iron oxide crystallites are spatially confined to the amorphous surface regions. This fact provides access to the elucidation of the mechanism of mechanosynthesis. It is demonstrated that the mechanosynthesized ferrite nanoparticles exhibit a partial superparamagnetism at room temperature. Quantitative information on the short-range structure and hyperfine interactions, provided by the nuclear spectroscopic technique, is complemented by an investigation of the magnetic behavior of nanostructured BiFeO3 on a macroscopic scale by means of SQUID technique. As a consequence of canted spins in the surface shell of nanoparticles, the mechanosynthesized BiFeO3 exhibits an enhanced magnetization, an enhanced coercivity, and a shifted hysteresis loop.
AB - A one-step synthesis of nanostructured bismuth ferrite (BiFeO3) via mechanochemical processing of a α-Fe2O3/Bi 2O3 mixture at room temperature is reported. The mechanically induced phase evolution of the mixture is followed by XRD and 57Fe Mössbauer spectroscopy. It is shown that the mechanosynthesis of the rhombohedrally distorted perovskite BiFeO3 phase is completed after 12 h. Compared to the traditional synthesis route, the mechanochemical process used here represents a one-step, high-yield, low-temperature, and low-cost procedure for the synthesis of BiFeO3. High-resolution TEM and XRD studies reveal a nonuniform structure of mechanosynthesized BiFeO3 nanoparticles consisting of a crystalline core surrounded by an amorphous surface shell. The latter is found to exhibit an extraordinarily high metastability causing a rapid crystallization of nanoparticles under irradiation with electrons. In situ high-resolution TEM observations of the crystallization clearly show that the heterogeneous processes of nucleation and growth of bismuth iron oxide crystallites are spatially confined to the amorphous surface regions. This fact provides access to the elucidation of the mechanism of mechanosynthesis. It is demonstrated that the mechanosynthesized ferrite nanoparticles exhibit a partial superparamagnetism at room temperature. Quantitative information on the short-range structure and hyperfine interactions, provided by the nuclear spectroscopic technique, is complemented by an investigation of the magnetic behavior of nanostructured BiFeO3 on a macroscopic scale by means of SQUID technique. As a consequence of canted spins in the surface shell of nanoparticles, the mechanosynthesized BiFeO3 exhibits an enhanced magnetization, an enhanced coercivity, and a shifted hysteresis loop.
UR - http://www.scopus.com/inward/record.url?scp=79954597302&partnerID=8YFLogxK
U2 - 10.1021/jp110128t
DO - 10.1021/jp110128t
M3 - Article
AN - SCOPUS:79954597302
VL - 115
SP - 7209
EP - 7217
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 15
ER -