We have investigated the magnetism of one-dimensional dipolar-interaction spin chains with perpendicular anisotropy by simulation. The behaviors of the magnetizations and the orientation correlations change dramatical...We have investigated the magnetism of one-dimensional dipolar-interaction spin chains with perpendicular anisotropy by simulation. The behaviors of the magnetizations and the orientation correlations change dramatically as the anisotropy increases to the critical value. The domain length can be controlled by adjusting the temperature and the external field as well as the anisotropy. These properties are interesting and arise from the competition between the anisotropy and the interaction along the chain.展开更多
We present a facile and controllable method for the large-scale fabrication of highly-ordered octahedral Fe3O4 colloidal ＂single crystals＂ without the assistance of a substrate. Oleic acid is used to reduce the solu...We present a facile and controllable method for the large-scale fabrication of highly-ordered octahedral Fe3O4 colloidal ＂single crystals＂ without the assistance of a substrate. Oleic acid is used to reduce the solubility of the nano-building blocks in colloidal solution and to induce a ＂crystallization＂ process. Our colloidal crystals are of multimicron size and show typical crystallographic characteristics. They have a very robust structure and can serve as a novel ordered magnetic mesoporous material with a relatively narrow pore size distribution. The sample possesses an extremely high Verwey transition temperature （Tv） of 100 K and a high saturation magnetization （Ms） of 86 emu/g at 5 K based on its good crystallinity, as well as the interparticle dipolar interaction behavior arising from its unique structure. Electrochemical measurements have demonstrated the excellent capacity of the mesoporous colloidal crystals when used in lithium-ion batteries.展开更多
基金Supported by the Doctorial Start-up Fund of Bohai University under Grant No.KYC-BSQD200901
文摘We have investigated the magnetism of one-dimensional dipolar-interaction spin chains with perpendicular anisotropy by simulation. The behaviors of the magnetizations and the orientation correlations change dramatically as the anisotropy increases to the critical value. The domain length can be controlled by adjusting the temperature and the external field as well as the anisotropy. These properties are interesting and arise from the competition between the anisotropy and the interaction along the chain.
文摘We present a facile and controllable method for the large-scale fabrication of highly-ordered octahedral Fe3O4 colloidal ＂single crystals＂ without the assistance of a substrate. Oleic acid is used to reduce the solubility of the nano-building blocks in colloidal solution and to induce a ＂crystallization＂ process. Our colloidal crystals are of multimicron size and show typical crystallographic characteristics. They have a very robust structure and can serve as a novel ordered magnetic mesoporous material with a relatively narrow pore size distribution. The sample possesses an extremely high Verwey transition temperature （Tv） of 100 K and a high saturation magnetization （Ms） of 86 emu/g at 5 K based on its good crystallinity, as well as the interparticle dipolar interaction behavior arising from its unique structure. Electrochemical measurements have demonstrated the excellent capacity of the mesoporous colloidal crystals when used in lithium-ion batteries.
