Synthesis of nickel zinc ferrite nanoparticle/organic hybrid from metalorganics

2007 ◽  
Vol 22 (7) ◽  
pp. 1967-1974 ◽  
Author(s):  
Yasuaki Hayashimto ◽  
Wataru Sakamoto ◽  
Toshinobu Yogo
Keyword(s):  
Zinc Ferrite ◽  
Oxide Particle ◽  
Organic Matrix ◽  
X Ray Diffraction ◽  
Organic Hybrid ◽  
Nickel Zinc ◽  
Ferrite Particle ◽  
Ferrite Nanoparticle ◽  
Hydrolysis Conditions

(Ni,Zn)Fe2O4 particle/organic hybrid was synthesized in situ from metalorganics below 100 °C. A mixture of nickel (II) acetylacetonate (NA), zinc acetylacetonate (ZA), and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding a spinel oxide particle/organic hybrid. X-ray diffraction analysis revealed that the crystallinity of spinel particles was dependent upon the hydrolysis conditions of NA-ZA-IAA. Nanocrystalline nickel zinc ferrite particles below 5 nm were uniformly dispersed in the organic matrix. The magnetization of hybrid increased with an increasing amount of water for hydrolysis. Nano-sized nickel zinc ferrite particle/organic hybrid showed a magnetization-applied field (BH) curve with no remanence above 40 K. The magnetization versus H/T curves from 40 to 100 K were superimposed on the same curve and satisfied the Langevin equation. The remanent magnetization and coercive field of the hybrid were 7.2 emu/g and 150 Oe, respectively, at 4.2 K. The absorption edge of the hybrid was blue-shifted compared with that of bulk ferrite.

In situ Synthesis of Nickel Ferrite Nanoparticle/organic Hybrid

2005 ◽  
Vol 20 (6) ◽  
pp. 1590-1596 ◽  
Author(s):  
Satoshi Nakamura ◽  
Wataru Sakamoto ◽  
Toshinobu Yogo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nickel Ferrite ◽  
Oxide Particle ◽  
Organic Matrix ◽  
X Ray ◽  
Organic Hybrid ◽  
Ferrite Particle ◽  
Ferrite Nanoparticle ◽  
Hydrolysis Conditions

A NiFe2O4 particle/organic hybrid was synthesized in situ from iron-organic and nickel organic compounds below 100 °C. A mixture of nickel (II) acetylacetonate (NA) and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding spinel oxide particle/oligomer hybrid. X-ray diffraction analysis revealed that the crystallinity of spinel particles was dependent upon the hydrolysis conditions of NA-IAA. Nanocrystalline nickel ferrite particles around 10 nm were uniformly dispersed in the organic matrix. The formation of nickel ferrite was confirmed by energy-dispersive x-ray and x-ray photoelectron spectroscopy. The saturation magnetization of hybrid increased with increasing water amount for hydrolysis. Nano-sized nickel ferrite particle/organic hybrid showed a BH curve with no remanence above 75 K. The magnetization versus H/T curves at 300, 200, and 75 K were superimposed on the same curve and satisfied the Langevin equation. The remanent magnetization and coercive field of the hybrid were 7.4 emu/g and 460 Oe, respectively, at 5 K.

In situ synthesis of lithium ferrite nanoparticle/polymer hybrid

2007 ◽  
Vol 22 (4) ◽  
pp. 974-981 ◽  
Author(s):  
Koichiro Hayashi ◽  
Wataru Sakamoto ◽  
Toshinobu Yogo
Keyword(s):  
Spinel Ferrite ◽  
Organic Matrix ◽  
Blocking Temperature ◽  
Lithium Ferrite ◽  
Zero Field ◽  
Organic Hybrid ◽  
Ferrite Particle ◽  
Ferrite Nanoparticle ◽  
Hydrolysis Conditions

Lithium ferrite particle/organic hybrid was synthesized in situ from iron–organic and lithium–organic compounds below 100 °C. Spinel ferrite particle/organic hybrid was synthesized by hydrolyzing a mixture of iron (III) 3-allylacetylacetonate (IAA) and lithium acrylate (LA). X-ray diffraction analysis revealed that the crystallinity of spinel particle was dependent on the polymerization treatment and the hydrolysis conditions. The saturation magnetization of hybrid increased with increasing methylhydrazine and water amount of hydrolysis. Nanocrystalline lithium ferrite particle about 5 nm was dispersed in the organic matrix. The hybrid showed neither remanence nor coercive force at room temperature. The magnetization versus field/temperature H/T curves from 100 to 300 K were superimposed on the same curve and satisfied the Langevin equation. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curve revealed that the blocking temperature was about 75 K. The remanent magnetization and coercive field of the hybrid were 8.9 A·m2/kg and 26.3 kA/m, respectively, at 10 K.

In situ synthesis of nano-sized cobalt ferrite particle/organic hybrid

2006 ◽  
Vol 21 (5) ◽  
pp. 1336-1341 ◽  
Author(s):  
Satoshi Nakamura ◽  
Wataru Sakamoto ◽  
Toshinobu Yogo
Keyword(s):  
Saturation Magnetization ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Organic Matrix ◽  
In Situ Synthesis ◽  
Organic Hybrid ◽  
Ferrite Particle ◽  
Hydrolysis Conditions ◽  
Cobalt Acetylacetonate

A CoFe2O4 particle/organic hybrid was synthesized using in situ processing of metalorganics of cobalt and iron below 100 °C. A mixture of cobalt (II) acetylacetonate (CA) and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding cobalt ferrite particle/organic hybrid. The crystallinity of cobalt ferrite depended upon the hydrolysis conditions of cobalt acetylacetonate-iron 3-allylacetylacetonate (CA-IAA). Nanocrystalline cobalt ferrite particles were uniformly dispersed in the organic matrix. The saturation magnetization of hybrid increased with increasing crystallinity of cobalt ferrite particles in the organic matrix. The hybrid showed a magnetization-applied field (BH) curve with no coercive force at room temperature. The magnetization versus H/T curves from 150 to 300 K were superimposed on the same curve and satisfied the Langevin equation. The hybrid revealed a saturation magnetization of 33.7 emu/g and a coercivity of 11 kOe at 4.2 K.

Synthesis of transparent magnetic particle/organic hybrid film using iron–organics

2000 ◽  
Vol 15 (10) ◽  
pp. 2114-2120 ◽  
Author(s):  
Toshinobu Yogo ◽  
Tomoyuki Nakamura ◽  
Wataru Sakamoto ◽  
Shin-ichi Hirano
Keyword(s):  
Iron Oxide ◽  
Magnetization Curve ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Hybrid Film ◽  
Oxide Particle ◽  
Iron Oxide Particle ◽  
Organic Hybrid ◽  
Hydrolysis Conditions

A transparent magnetic particle/organic film was synthesized from an iron–organic compound. Iron(III) 3-allylacetylacetonate (IAA) was polymerized followed by in situ hydrolysis yielding an iron oxide particle/oligomer hybrid. The sizes of magnetic particles were dependent upon the hydrolysis conditions of the IAA oligomers. A nanometer-sized ferrimagnetic iron oxide particle/oligomer hybrid showed a magnetization curve with no coercive force at 300 K and that with Hc of 200 Oe at 4.2 K, respectively. The magnetization versus H/T curves at 300 and 77 K were superimposed on each other and satisfied the Langevin equation. The transparent hybrid film showed a magnetization curve at room temperature. The absorption spectrum of the film was shifted to higher energy by 0.14 eV compared with that of bulk magnetite. The absorption edge of the film was blue-shifted.

Synthesis of Carbon/Ferrite Composite by In-Situ Pressure Pyrolysis of Organometallic Polymers

1992 ◽  
Vol 274 ◽  
Author(s):  
Shin-Ichi Hirano ◽  
Toshinobu Yogo ◽  
Koichi Kikuta ◽  
Makoto Fukuda
Keyword(s):  
Coercive Force ◽  
Supercritical Water ◽  
Nickel Ferrite ◽  
Zinc Ferrite ◽  
Carbon Matrix ◽  
Carbon Composite ◽  
Organometallic Polymers ◽  
Nickel Zinc ◽  
Ferrite Particle

ABSTRACTFerrite particle-dispersed carbon composite were synthesized by in-situ pressure pyrolysis of organometallic polymers at temperatures from 500 to 700°C under 125 MPa. Magnetite-dispersed carbon composite could be prepared from 550 to 700°C at 125 MPa. Nickel and nickel zinc ferrite particles were dispersed in carbon matrices at 550°C and 500°C, respectively, under 125 MPa. The morphology of the carbon matrix can be controlled by the pyrolysis conditions and the amount of coexistent supercritical water. Carbon spherulites of several micrometers dispersed with ferrite particles less than 100 nm were successfully synthesized by pressure pyrolysis of organometallic polymers in the presence of supercritical water. The saturation magnetization of magnetite-, nickel ferrite- and nickel zinc ferrite-dispersed carbon were 74, 30 and 65 emu/g, respectively. The coercive force of nickel ferrite-dispersed carbon was about 200 Oe.

Synthesis of magnetic particle/organic hybrid from metalorganic compounds

1999 ◽  
Vol 14 (7) ◽  
pp. 2855-2860 ◽  
Author(s):  
Toshinobu Yogo ◽  
Tomoyuki Nakamura ◽  
Wataru Sakamoto ◽  
Shin-ichi Hirano
Keyword(s):  
Iron Oxide ◽  
Magnetic Particle ◽  
Oxide Particle ◽  
Iron Oxide Particle ◽  
X Ray Diffraction ◽  
Organic Hybrid ◽  
Reducing Conditions ◽  
Nanocrystalline Particles ◽  
Oxide Spinel

A nanocrystalline magnetic particle/oligomer hybrid was successfully synthesized by polymerization of iron(III) 3-allylacetylacetonate (IAA) followed by in situ hydrolysis. An iron oxide particle/oligomer hybrid was synthesized by hydrolysis of the IAA oligomer under alkaline and reducing conditions by the addition of hydrazine or methylhydrazine. Crystalline particles of approximately 10 nm were found to be dispersed in the oligomeric matrix. The nanocrystalline particles were identified to be iron oxide spinel by x-ray diffraction analysis and electron diffraction. The nanometer-sized ferrimagnetic iron oxide particle/oligomer hybrid showed a typical superparamagnetic behavior.

scholarly journals In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

2016 ◽  
Vol 56 ◽  
pp. 68-72 ◽  
Author(s):  
S. Ferrari ◽  
R.S. Kumar ◽  
F. Grinblat ◽  
J.C. Aphesteguy ◽  
F.D. Saccone ◽  
...  
Keyword(s):  
High Pressure ◽  
Diffraction Study ◽  
Zinc Ferrite ◽  
Ferrite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray

Synthesis of spinel iron oxide nanoparticle/organic hybrid for hyperthermia

2008 ◽  
Vol 23 (12) ◽  
pp. 3415-3424 ◽  
Author(s):  
Koichiro Hayashi ◽  
Toshifumi Shimizu ◽  
Hidefumi Asano ◽  
Wataru Sakamoto ◽  
Toshinobu Yogo
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Iron Oxide Nanoparticle ◽  
Organic Hybrid ◽  
Oxide Nanoparticle ◽  
Hydrolysis Conditions ◽  
Size Controlled ◽  
Controlled Hydrolysis

Size-controlled spinel iron oxide (SIO) nanoparticle/organic hybrid was synthesized in situ from iron (III) allylacetylacetonate (IAA) at around 80 °C. The formation of SIO particles chemically bound with organics was confirmed by infrared and x-ray photoelectron spectroscopy. The sizes of SIO nanoparticles in the hybrids were monodispersed and ranged from 7 to 23 nm under controlled hydrolysis conditions. The hybrid including SIO particles of 7.3 nm was superparamagnetic, whereas those dispersed with particles above 11 nm were ferrimagnetic. The specific absorption rate (SAR) value was dependent upon the magnetic properties of the hybrid at 100 Oe. The SAR was 15.2 W g−1 in a 230 kHz alternating magnetic field and 100 Oe when the crystallite size of SIO particle in the hybrid was 16 nm. The temperatures of agars dispersed with hybrid powders of 5 and 8 mg ml−1 reached the optimum temperature (42 °C) for 17 and 8 min, respectively. The increase in temperature was controlled in terms of the strength of magnetic field. The simulation of heat transfer in the agar phantom model revealed that the suitable temperature distribution for therapy was attained from 15 to 20 min at 230 kHz and 100 Oe.

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