Hematite (α-Fe2O3) nanopowder was synthesized from 0.1 mol·L-1 FeCl3 solution by sonochemical hydrolysis method, and characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier tran...Hematite (α-Fe2O3) nanopowder was synthesized from 0.1 mol·L-1 FeCl3 solution by sonochemical hydrolysis method, and characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), Fourier transform Raman (FT-Raman) and X-ray photoelectron spectroscopy (XPS). The results showed that the spherical, well-dispersed α-Fe2O3 nanopowder was obtained with the average size of 20 nm. The possible mechanism for the formation of α-Fe2O3 nanoparticals was also discussed.展开更多
Four different hematite (-Fe2O3) nanopowders with various morphologi es have been synthesized in the presence of surfactant (HPC) via hydrothermal ro ute at 180 ℃, using four kinds of iron salts, Fe2(SO4)3, FeC2O4, F...Four different hematite (-Fe2O3) nanopowders with various morphologi es have been synthesized in the presence of surfactant (HPC) via hydrothermal ro ute at 180 ℃, using four kinds of iron salts, Fe2(SO4)3, FeC2O4, FeSO4 and (NH4 )3Fe(C2O4)3, as precursor materials. The products were characterized by means of X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transf orm infrared spectroscopy (FTIR) and magnetization measurements. The hysteresis measurements show that the products exhibit weak ferromagnetic property at room temperature. It is concluded that the different precursor materials and the pres ence of the surfactant are important factors that exert significant effects on t he morphologies and magnetic properties of the products.展开更多
The Fe(OH) 3 precursor was prepared by solid-state reaction with Fe(NO 3 ) 3 ·9H 2 O,NaOH and dispersed poly-ethylene glycol at low heating temperature(25℃).Synthesis of iron oxide(γ-Fe 2 O 3 )nanoparticle was ...The Fe(OH) 3 precursor was prepared by solid-state reaction with Fe(NO 3 ) 3 ·9H 2 O,NaOH and dispersed poly-ethylene glycol at low heating temperature(25℃).Synthesis of iron oxide(γ-Fe 2 O 3 )nanoparticle was achieved by thermal decomposition of Fe(OH) 3 ·xH 2 O precursor.The nanoparticle was characterized by TG-DTA,X-ray diffra-ction,TEM etc.The results showed that the nanoparticle was composed ofγ-Fe 2 O 3 and was a better absorber for electromagnetic wave within the low frequency band.展开更多
Nano-MgFe2O4-Fe2O3 magnetic powders were synthesized by citrate gel under microwave irradiation. The structure,particle size distribution,electromagnetic characteristics of nano-MgFe2O4-Fe2O3 were characterized by usi...Nano-MgFe2O4-Fe2O3 magnetic powders were synthesized by citrate gel under microwave irradiation. The structure,particle size distribution,electromagnetic characteristics of nano-MgFe2O4-Fe2O3 were characterized by using TG-DTA, X-ray, electronic microscope, nano-size measurement and electromagnetism measurement apparatus?The results show that the product is a mixture of MgFe2O4 and Fe2O3 with average size of 44 nm, tanδ for the product is 0.265 and 0.610 at frequency of 1.0 GHz and 1.8 GHz respectively.展开更多
文摘Hematite (α-Fe2O3) nanopowder was synthesized from 0.1 mol·L-1 FeCl3 solution by sonochemical hydrolysis method, and characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), Fourier transform Raman (FT-Raman) and X-ray photoelectron spectroscopy (XPS). The results showed that the spherical, well-dispersed α-Fe2O3 nanopowder was obtained with the average size of 20 nm. The possible mechanism for the formation of α-Fe2O3 nanoparticals was also discussed.
文摘Four different hematite (-Fe2O3) nanopowders with various morphologi es have been synthesized in the presence of surfactant (HPC) via hydrothermal ro ute at 180 ℃, using four kinds of iron salts, Fe2(SO4)3, FeC2O4, FeSO4 and (NH4 )3Fe(C2O4)3, as precursor materials. The products were characterized by means of X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transf orm infrared spectroscopy (FTIR) and magnetization measurements. The hysteresis measurements show that the products exhibit weak ferromagnetic property at room temperature. It is concluded that the different precursor materials and the pres ence of the surfactant are important factors that exert significant effects on t he morphologies and magnetic properties of the products.
文摘The Fe(OH) 3 precursor was prepared by solid-state reaction with Fe(NO 3 ) 3 ·9H 2 O,NaOH and dispersed poly-ethylene glycol at low heating temperature(25℃).Synthesis of iron oxide(γ-Fe 2 O 3 )nanoparticle was achieved by thermal decomposition of Fe(OH) 3 ·xH 2 O precursor.The nanoparticle was characterized by TG-DTA,X-ray diffra-ction,TEM etc.The results showed that the nanoparticle was composed ofγ-Fe 2 O 3 and was a better absorber for electromagnetic wave within the low frequency band.
文摘Nano-MgFe2O4-Fe2O3 magnetic powders were synthesized by citrate gel under microwave irradiation. The structure,particle size distribution,electromagnetic characteristics of nano-MgFe2O4-Fe2O3 were characterized by using TG-DTA, X-ray, electronic microscope, nano-size measurement and electromagnetism measurement apparatus?The results show that the product is a mixture of MgFe2O4 and Fe2O3 with average size of 44 nm, tanδ for the product is 0.265 and 0.610 at frequency of 1.0 GHz and 1.8 GHz respectively.
