Abstract
Magnetic nanocomposites containing magnetite (Fe 3O 4) nanoparticles were prepared from iron oxide microtubules produced by Leptothrix ochracea, a species of water-habitant iron-oxidizing bacteria. The microtubules were mainly composed of Si-containing ferric hydroxide that shows a broad X-ray diffraction pattern similar to that of 2-line ferrihydrite. After moderate heat treatment in a reductive atmosphere above 325 °C, the ferric ions were partially reduced to a ferrous state, and nanocrystalline Fe 3O 4 with a spinel-type structure was formed in a noncrystalline silicate matrix. The average crystallite size of the Fe 3O 4 nanoparticles was estimated to be in the order of a few nanometers. The sample heat-treated at 500 °C exhibited considerable magnetization together with superparamagnetic behavior at room temperature, and super-spin-glass interaction occurred at low temperature. On further heat treatment above 530 °C, Fe 3O 4 was reduced to wüstite (Fe 1 -xO) and finally crystallized into iron metal (α-Fe) and ferrous silicate (Fe 2SiO 4).
| Original language | English |
|---|---|
| Pages (from-to) | 1156-1161 |
| Number of pages | 6 |
| Journal | Materials Chemistry and Physics |
| Volume | 136 |
| Issue number | 2-3 |
| DOIs | |
| Publication status | Published - Oct 15 2012 |
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Keywords
- Amorphous materials
- Heat treatment
- Magnetic materials
- Magnetometer (for magnetic field, susceptibility, magnetic moment, magnetisation measurements)
- Nanostructures
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
Cite this
Synthesis and magnetic properties of magnetite-silicate nanocomposites derived from iron oxide of bacterial origin. / Hashimoto, Hideki; Fujii, Tatsuo; Nakanishi, Makoto; Kusano, Yoshihiro; Ikeda, Yasunori; Takada, Jun.
In: Materials Chemistry and Physics, Vol. 136, No. 2-3, 15.10.2012, p. 1156-1161.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis and magnetic properties of magnetite-silicate nanocomposites derived from iron oxide of bacterial origin
AU - Hashimoto, Hideki
AU - Fujii, Tatsuo
AU - Nakanishi, Makoto
AU - Kusano, Yoshihiro
AU - Ikeda, Yasunori
AU - Takada, Jun
PY - 2012/10/15
Y1 - 2012/10/15
N2 - Magnetic nanocomposites containing magnetite (Fe 3O 4) nanoparticles were prepared from iron oxide microtubules produced by Leptothrix ochracea, a species of water-habitant iron-oxidizing bacteria. The microtubules were mainly composed of Si-containing ferric hydroxide that shows a broad X-ray diffraction pattern similar to that of 2-line ferrihydrite. After moderate heat treatment in a reductive atmosphere above 325 °C, the ferric ions were partially reduced to a ferrous state, and nanocrystalline Fe 3O 4 with a spinel-type structure was formed in a noncrystalline silicate matrix. The average crystallite size of the Fe 3O 4 nanoparticles was estimated to be in the order of a few nanometers. The sample heat-treated at 500 °C exhibited considerable magnetization together with superparamagnetic behavior at room temperature, and super-spin-glass interaction occurred at low temperature. On further heat treatment above 530 °C, Fe 3O 4 was reduced to wüstite (Fe 1 -xO) and finally crystallized into iron metal (α-Fe) and ferrous silicate (Fe 2SiO 4).
AB - Magnetic nanocomposites containing magnetite (Fe 3O 4) nanoparticles were prepared from iron oxide microtubules produced by Leptothrix ochracea, a species of water-habitant iron-oxidizing bacteria. The microtubules were mainly composed of Si-containing ferric hydroxide that shows a broad X-ray diffraction pattern similar to that of 2-line ferrihydrite. After moderate heat treatment in a reductive atmosphere above 325 °C, the ferric ions were partially reduced to a ferrous state, and nanocrystalline Fe 3O 4 with a spinel-type structure was formed in a noncrystalline silicate matrix. The average crystallite size of the Fe 3O 4 nanoparticles was estimated to be in the order of a few nanometers. The sample heat-treated at 500 °C exhibited considerable magnetization together with superparamagnetic behavior at room temperature, and super-spin-glass interaction occurred at low temperature. On further heat treatment above 530 °C, Fe 3O 4 was reduced to wüstite (Fe 1 -xO) and finally crystallized into iron metal (α-Fe) and ferrous silicate (Fe 2SiO 4).
KW - Amorphous materials
KW - Heat treatment
KW - Magnetic materials
KW - Magnetometer (for magnetic field, susceptibility, magnetic moment, magnetisation measurements)
KW - Nanostructures
UR - http://www.scopus.com/inward/record.url?scp=84867398146&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84867398146&partnerID=8YFLogxK
U2 - 10.1016/j.matchemphys.2012.08.070
DO - 10.1016/j.matchemphys.2012.08.070
M3 - Article
AN - SCOPUS:84867398146
VL - 136
SP - 1156
EP - 1161
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
SN - 0254-0584
IS - 2-3
ER -