Slawomir M. Kaczmarek; Tomasz Bodziony; Vinh H. Tran; Pawal Figiel; Anna Biedunkiewicz; Grzegorz Leniec
Abstract
Series of nanocrystalline and TiC, TiB2, and B4C powders as dopants (3%-20%) embedded in an AISI 316L austenitic steel have been prepared and investigated by ferromagnetic resonance and magnetic measurements. The homogeneous composites with the dopants up to x = 7 vol. % exhibit superparamagnetic properties, ...
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Series of nanocrystalline and TiC, TiB2, and B4C powders as dopants (3%-20%) embedded in an AISI 316L austenitic steel have been prepared and investigated by ferromagnetic resonance and magnetic measurements. The homogeneous composites with the dopants up to x = 7 vol. % exhibit superparamagnetic properties, characterized by bifurcation between the field-cooled MFC(T) and zero-field cooled MZFC(T) magnetization below Tir and a maximum at Tmax in low-field MZFC(T) curves. We found that the Tir and Tmax values depend proportionally on the dopant concentrations x. The magnetization measurements in fields above 1000 Oe suggested an induced phase transition from superparamagnetic state to ferromagnetic one but presumably without long-range magnetic correlation. An analysis of magnetic anisotropic energy barrier distributions implied that different sizes and compositional types of dopants may contribute to the superparamagnetic relaxation process. The results demonstrate the possibility of obtaining new steel-based materials with desired properties and potential applications as combining magnetic and mechanical advantages.
Atul B. Lavand; Yuvraj S. Malghe
Abstract
Nanosized bare, C and N doped as well as C, N co-doped ZnO nanopowders were prepared using microemulsion method. Synthesized powders were characterized using X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy ...
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Nanosized bare, C and N doped as well as C, N co-doped ZnO nanopowders were prepared using microemulsion method. Synthesized powders were characterized using X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), CHNS analyzer, photoluminescence spectrophotometer and UV-visible spectrophotometer. XRD study shows that C, N co-doped ZnO have hexagonal wurtzite structure. UV-visible spectral study reveals that C and N co-doping improves photo absorption capacity in visible region. Visible light photocatalytic degradation of malachite green was carried out using nanosized bare, C doped and C, N co-doped ZnO. C, N co-doped ZnO exhibits better visible light photocatalytic activity as compared to pure and C doped ZnO. Also the photocatalyst prepared is stable and can be reused repeatedly.
Atul B. Lavand; Yuvraj S. Malghe
Abstract
Nanosized bare and carbon (C)-doped TiO2 were prepared using reverse micro-emulsion method. Synthesized powders were characterized with the help of X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDX) and UV-visible ...
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Nanosized bare and carbon (C)-doped TiO2 were prepared using reverse micro-emulsion method. Synthesized powders were characterized with the help of X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscope (EDX) and UV-visible spectrophotometer. EDX study reveals that as calcination temperature increases amount of C on TiO2 decreases. SEM and TEM images show that TiO2 particles are spherical in shape and after increasing the calcination temperature size of particle increases. Particle size of TiO2 obtained from TEM data varies between 10 to 17nm. Visible light photocatalytic degradation of 2,4,6-trichlorophenol (TCP) aqueous solution was carried out using nanosized bare as well as C-doped TiO2. UV-visible spectrophotometer and high pressure liquid chromatography (HPLC) techniques were used to analyze the concentration of TCP during the degradation process. In presence of visible light C-doped TiO2 obtained after calcination of precursor at 300°C shows better photocatalytic activity. Parameters affecting the photocatalytic process such as calcination temperature, amount of catalyst and TCP concentration are investigated. TCP photocatalytic degradation process was optimized. It is observed that to get better photocatalytic activity optimum amount of photocatalyst and concentration of TCP solution required are 1.0 gL -1 and 20 mg L -1 respectively. Reusability study indicates that C doped TiO2 prepared in the present work is highly stable and reusable photo catalyst.
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