http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cobalt ferrite nanotubes and porous nanorods for dye removal
Girgis, E.,Adel, D.,Tharwat, C.,Attallah, O.,Rao, K.V. Techno-Press 2015 Advances in nano research Vol.3 No.2
$CoFe_2O_4$ nanotubes and porous nanorods were prepared via a simple one-pot template-free hydrothermal method and were used as an adsorbent for the removal of dye contaminants from water. The properties of the synthesized nanotubes and porous nanorods were characterized by electron diffraction, transmission electron microscopy and x-ray powder diffraction. The Adsorption characteristics of the $CoFe_2O_4$ were examined using polar red dye and the factors affecting adsorption, such as, initial dye concentration, pH and contact time were evaluated. The overall trend followed an increase of the sorption capacity reaching a maximum of 95% dye removal at low pHs of 2-4. An enhancement in the removal efficiency was also noticed upon increasing the contact time between dye molecules and $CoFe_2O_4$ nanoparticles. The final results indicated that the $CoFe_2O_4$ nanotubes and porous nanorods can be considered as an efficient low cost and recyclable adsorbent for dye removal with efficiency 94% for Cobalt ferrite nanotubes and for Cobalt ferrite porous nanorods equals 95%.
Magnetization Process in Vortex-imprinted Ni₈₀Fe₂₀/Ir₂₀Mn₈₀ Square Elements
H. Xu,J. Kolthammer,J. Rudge,E. Girgis,B. C. Choi,Y. K. Hong,G. Abo,Th. Speliotis,D. Niarchos 한국자기학회 2011 Journal of Magnetics Vol.16 No.2
The vortex-driven magnetization process of micron-sized, exchange-coupled square elements with composition of Ni??Fe₂? (12 ㎚)/Ir₂?Mn?? (5 ㎚) is investigated. The exchange-bias is introduced by field-cooling through the blocking temperature (TB) of the system, whereby Landau-shaped vortex states of the Ni??Fe₂? layer are imprinted into the Ir₂?Mn??. In the case of zero-field cooling, the exchange-coupling at the ferromagnetic/antiferromagnetic interface significantly enhances the vortex stability by increasing the nucleation and annihilation fields, while reducing coercivity and remanence. For the field-cooled elements, the hysteresis loops are shifted along the cooling field axis. The loop shift is attributed to the imprinting of displaced vortex state of Ni??Fe₂? into Ir₂?Mn??, which leads to asymmetric effective local pinning fields at the interface. The asymmetry of the hysteresis loop and the strength of the exchange-bias field can be tuned by varying the strength of cooling field. Micromagnetic modeling reproduces the experimentally observed vortex-driven magnetization process if the local pinning fields induced by exchange-coupling of the ferromagnetic and antiferromagnetic layers are taken into account.