Continuous synthesis of fine MgFe 2O 4 nanoparticles by supercritical hydrothermal reaction

We produced magnesium ferrite (MgFe 2O 4) nanoparticles by hydrothermal synthesis in supercritical water. Suspensions containing varying ratios of Mg(OH) 2 and Fe(OH) 3 at room temperature were pressurized to 30 MPa, fed into a tubular reactor by high-pressure pump, and rapidly heated to reaction te...

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Bibliographic Details
Published inThe Journal of supercritical fluids Vol. 53; no. 1; pp. 92 - 94
Main Authors Sasaki, Takafumi, Ohara, Satoshi, Naka, Takashi, Vejpravova, Jana, Sechovsky, Vladimir, Umetsu, Mitsuo, Takami, Seiichi, Jeyadevan, Balachandran, Adschiri, Tadafumi
Format Journal Article
LanguageEnglish
Published Elsevier B.V 2010
Subjects
Flow method
Hydrothermal synthesis
MgFe 2O 4
Supercritical water
VSM
DDS
Hydrothermal synthesis
SQUID
ZFC
Supercritical water
Flow method
XRD
FC
TEM
MgFe 2O 4
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Summary:We produced magnesium ferrite (MgFe 2O 4) nanoparticles by hydrothermal synthesis in supercritical water. Suspensions containing varying ratios of Mg(OH) 2 and Fe(OH) 3 at room temperature were pressurized to 30 MPa, fed into a tubular reactor by high-pressure pump, and rapidly heated to reaction temperature by mixing with supercritical water. The MgFe 2O 4 phase forms at 460 °C. The Mg/Fe molar ratio was varied from 0.5 to 1.5 with the goal of obtaining single-phase MgFe 2O 4. At the stoichiometric ratio for MgFe 2O 4, Mg/Fe = 0.5, the product contains both MgFe 2O 4 and α-Fe 2O 3. At Mg/Fe = 1.0 and 1.5, the product is the desired single-phase MgFe 2O 4. The synthesized MgFe 2O 4 nanoparticles, with particle size of about 20 nm, exhibit superparamagnetic behavior.
ISSN:0896-8446
1872-8162
DOI:10.1016/j.supflu.2009.11.005