This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol...This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.展开更多
Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spe...Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy,scanning electron microscopy,surface analysis using the Brunauer-Emmett-Teller method,and energy-dispersive X-ray spectroscopy.Antimicrobial activity of these ferrites against selected pathogenic microbes was determined.The structures remained cubic spinel phases after substitution of metals.Substitution strongly influenced the microstructure and homoge- neous grain distribution.The particle size of the ferrites increased linearly with increase in their annealing temperature.The surface area of zinc cobalt ferrite nanoparticles (ZCFO)was 52.56m^2/g,the average pore size was 1.84nm,and pore volume was 0.136mL/g.All ferrites showed antimicrobial activity toward all pathogens selected.Of these,the most powerful was ZCFO,showing zones of inhibition of 13.0mm against Bacillus subtilis and Staphylococcus aureus and 12.0mm against Candida albicans.Gamma-irradiated ZCFO nanoparticles (150.0kGy)maintained higher antimicrobial activity than non-irradiated particles,e.g. being active toward S.aureus (16.0mm).ZCFO is proposed as a candidate material for industrial and biomedical purposes.展开更多
基金the Materials Science Unit,Radiation Physics Department,National Center for Radiation Research and Technology,Egypt,for financing and supporting this study under the project Nanostructured Magnetic Materials。
文摘This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.
文摘Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy,scanning electron microscopy,surface analysis using the Brunauer-Emmett-Teller method,and energy-dispersive X-ray spectroscopy.Antimicrobial activity of these ferrites against selected pathogenic microbes was determined.The structures remained cubic spinel phases after substitution of metals.Substitution strongly influenced the microstructure and homoge- neous grain distribution.The particle size of the ferrites increased linearly with increase in their annealing temperature.The surface area of zinc cobalt ferrite nanoparticles (ZCFO)was 52.56m^2/g,the average pore size was 1.84nm,and pore volume was 0.136mL/g.All ferrites showed antimicrobial activity toward all pathogens selected.Of these,the most powerful was ZCFO,showing zones of inhibition of 13.0mm against Bacillus subtilis and Staphylococcus aureus and 12.0mm against Candida albicans.Gamma-irradiated ZCFO nanoparticles (150.0kGy)maintained higher antimicrobial activity than non-irradiated particles,e.g. being active toward S.aureus (16.0mm).ZCFO is proposed as a candidate material for industrial and biomedical purposes.
