α-Fe2O3 nanoparticles were successfully prepared by a sonochemical method in FeCl3-NH3 complex solution.The obtained sample was examined and investigated by XRD,TEM,FT-IR,FT-Raman and XPS techniques.The results showe...α-Fe2O3 nanoparticles were successfully prepared by a sonochemical method in FeCl3-NH3 complex solution.The obtained sample was examined and investigated by XRD,TEM,FT-IR,FT-Raman and XPS techniques.The results showed that the spherical,well-dispersed α-Fe2O3 nanoparticles were obtained with the average size of 15nm.The possible formation mechanism of α-Fe2O3 nanoparticles were also discussed,which indicated that this for the preparation of the nanoparticles method can be used for α-Fe2O3 preparation with some practical and universal significance.展开更多
Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from ...Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from 0 25 mol/L FeCl 2 and (NH 3) 2CO 3 in 0.1% surfactant solution at pH=4, 105 ℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS∶ styrene∶H 2O(mass fraction)=0 1∶1∶9, 85 ℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20～50 nm and showed magnetic property.展开更多
Fe2O3 nanoparticles doped with La（Ⅲ） was prepared using iron citrate as starting material via sol-gel method.Iron oxide nanoparticles were characterized using X-ray diffration, transmission election mieroscope, FTI...Fe2O3 nanoparticles doped with La（Ⅲ） was prepared using iron citrate as starting material via sol-gel method.Iron oxide nanoparticles were characterized using X-ray diffration, transmission election mieroscope, FTIR and BET,respectively.There was no obvious phase transpfrmation for the sample doped with 4 wt% La2O3 after heating at 400℃ for 8h.This suggests that the transition of the γ-Fe2O3 to the α-Fe2O3,which is thermodynamically stable phase,be effectively suppressed by La（Ⅲ）doping.Meanwhile, the existence of La（Ⅲ）on the surfaces of the nanopar-ticles also takes the role of restraining the particles aggregation during heating process.展开更多
Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-...Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.展开更多
文摘α-Fe2O3 nanoparticles were successfully prepared by a sonochemical method in FeCl3-NH3 complex solution.The obtained sample was examined and investigated by XRD,TEM,FT-IR,FT-Raman and XPS techniques.The results showed that the spherical,well-dispersed α-Fe2O3 nanoparticles were obtained with the average size of 15nm.The possible formation mechanism of α-Fe2O3 nanoparticles were also discussed,which indicated that this for the preparation of the nanoparticles method can be used for α-Fe2O3 preparation with some practical and universal significance.
文摘Nanoparticles of polystyrene/α Fe 2O 3 composites were prepared by method of insertion in sodium dodecylbenzene sulfonate(SDBS) micellar system. The orange α Fe 2O 3 particles of about 6 nm were first prepared from 0 25 mol/L FeCl 2 and (NH 3) 2CO 3 in 0.1% surfactant solution at pH=4, 105 ℃ for 10 h. The title nanoparticles were prepared then in conditions of SDBS∶ styrene∶H 2O(mass fraction)=0 1∶1∶9, 85 ℃, 8 h, using ammonium persulfate(APS) as an initiator. The composite nanoparticles sized in 20～50 nm and showed magnetic property.
文摘Fe2O3 nanoparticles doped with La（Ⅲ） was prepared using iron citrate as starting material via sol-gel method.Iron oxide nanoparticles were characterized using X-ray diffration, transmission election mieroscope, FTIR and BET,respectively.There was no obvious phase transpfrmation for the sample doped with 4 wt% La2O3 after heating at 400℃ for 8h.This suggests that the transition of the γ-Fe2O3 to the α-Fe2O3,which is thermodynamically stable phase,be effectively suppressed by La（Ⅲ）doping.Meanwhile, the existence of La（Ⅲ）on the surfaces of the nanopar-ticles also takes the role of restraining the particles aggregation during heating process.
文摘Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.
