One-dimensional（ID） In2O3（ZnO）m superlattice nanobelts are synthesized by a chemical vapor deposition method.The formation of the In2O3（ZnO）m superlattice is verified by the high-resolution transmission electron...One-dimensional（ID） In2O3（ZnO）m superlattice nanobelts are synthesized by a chemical vapor deposition method.The formation of the In2O3（ZnO）m superlattice is verified by the high-resolution transmission electron microscopy images.The typical zigzag boundaries could be clearly observed.An additional peak at 614 cm^-1 is found in the Raman spectrum,which may correspond to the superlattice structure.The study about the electrical transport properties reveals that the In2O3（ZnO）m nanobelts exhibit peculiar nonlinear I-V characteristics even under the Ohmic contact measurement condition,which are different from the Ohmic behaviors of the In-doped ZnO nanobelts.The photoelectrical measurements show the differences in the photocurrent property between them,and their transport mechanisms are also discussed.展开更多
Microstructure of high-quality YBa2Cu3O7-x superlattices has been investigated using high-resolution transmission electron microscope (HRTEM). The observations revealed that the superlattioes had atomic sharp interfac...Microstructure of high-quality YBa2Cu3O7-x superlattices has been investigated using high-resolution transmission electron microscope (HRTEM). The observations revealed that the superlattioes had atomic sharp interfaces between YBCO and PrBCO layers without interdiffusion. But undulations and. steps of the layer thickness existed in the specimen. An intermediate layer about 1 nm in thickness with many defects, which was caused by the surface steps and dislocations at SrTiO3 substrate surface, was observed at the film-substrate interfaces. However, the films did not have large extended defects beyond several unit cells. The results suggested that when studying the two-dimensional transport properties and superconducting mechanism of YACO using YBCO/PrBCO superlattioes or ultra-thin YBCO films, the influence of the micro-structural elements must be taken into account.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 National Natural Science Foundation of China(Grant No.51172058)the Key Project of the Science Technology and Research Project of Education Bureau,Heilongjiang Province,China(Grant No.12521z012)the Natural Science Foundation of Heilongjiang Province for Returned Chinese Scholars,China(Grant No.LC2013C17)
文摘One-dimensional（ID） In2O3（ZnO）m superlattice nanobelts are synthesized by a chemical vapor deposition method.The formation of the In2O3（ZnO）m superlattice is verified by the high-resolution transmission electron microscopy images.The typical zigzag boundaries could be clearly observed.An additional peak at 614 cm^-1 is found in the Raman spectrum,which may correspond to the superlattice structure.The study about the electrical transport properties reveals that the In2O3（ZnO）m nanobelts exhibit peculiar nonlinear I-V characteristics even under the Ohmic contact measurement condition,which are different from the Ohmic behaviors of the In-doped ZnO nanobelts.The photoelectrical measurements show the differences in the photocurrent property between them,and their transport mechanisms are also discussed.
文摘Microstructure of high-quality YBa2Cu3O7-x superlattices has been investigated using high-resolution transmission electron microscope (HRTEM). The observations revealed that the superlattioes had atomic sharp interfaces between YBCO and PrBCO layers without interdiffusion. But undulations and. steps of the layer thickness existed in the specimen. An intermediate layer about 1 nm in thickness with many defects, which was caused by the surface steps and dislocations at SrTiO3 substrate surface, was observed at the film-substrate interfaces. However, the films did not have large extended defects beyond several unit cells. The results suggested that when studying the two-dimensional transport properties and superconducting mechanism of YACO using YBCO/PrBCO superlattioes or ultra-thin YBCO films, the influence of the micro-structural elements must be taken into account.
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.
