Ultrafast electron diffraction (UED) is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing ...Ultrafast electron diffraction (UED) is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing this UED apparatus, both the coherent and the concurrent thermal lattice motions in an aluminium thin-film, trigged by ultrafast laser heating, have been observed. These results demonstrate its ability to directly measure a sub-milli-angstrom lattice spacing change on a sub-picosecond time scale.展开更多
The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E ...The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E and momentum p of photonic eigenmodes, and essentially determines the optical properties of materials. As EepT is defined in momentum space(k-space), the experimental method to detect the energy distribution, that is the spectrum, in a momentum-resolved manner is highly required. In this review, the momentum-space imaging spectroscopy(MSIS) system is presented, which can directly study the spectral information in momentum space. Using the MSIS system, the photonic dispersion can be captured in one shot with high energy and momentum resolution. From the experimental momentumresolved spectrum data, other key features of photonic eigenmodes, such as quality factors and polarization states, can also be extracted through the post-processing algorithm based on the coupled mode theory. In addition, the interference configurations of the MSIS system enable the measurement of coherence properties and phase information of nanophotonic materials, which is important for the study of light-matter interaction and beam shaping with nanostructures. The MSIS system can give the comprehensive information of nanophotonic materials, and is greatly useful for the study of novel photonic phenomena and the development of nanophotonic technologies.展开更多
The nanoscale effect enables the unique magnetic,optical,thermal and electrical properties of nanostructured materials and has attracted extensive investigation for applications in catalysis,biomedicine,sensors,and en...The nanoscale effect enables the unique magnetic,optical,thermal and electrical properties of nanostructured materials and has attracted extensive investigation for applications in catalysis,biomedicine,sensors,and energy storage and conversion.The widely used synthesis methods,such as traditional hydrothermal reaction and calcination,are bulk heating processes based on thermal radiation.Differing from traditional heating methods,non-thermal radiation heating technique is a local heating mode.In this regard,this review summarizes various non-thermal radiation heating methods for synthesis of nanomaterials,including microwave heating,induction heating,Joule heating,laser heating and electron beam heating.The advantages and disadvantages of these non-thermal radiation heating methods for the synthesis of nanomaterials are compared and discussed.Finally,the future development and challenges of non-thermal radiation heating method for potential synthesis of nanomaterials are discussed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10728409, 10734130, 10735050 and 60621063, and the National Basic Research Programme of China under Grant No 2007CB815102.
文摘Ultrafast electron diffraction (UED) is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing this UED apparatus, both the coherent and the concurrent thermal lattice motions in an aluminium thin-film, trigged by ultrafast laser heating, have been observed. These results demonstrate its ability to directly measure a sub-milli-angstrom lattice spacing change on a sub-picosecond time scale.
基金supported by the National Key Basic Research Program of China(2016YFA0301103,2016YFA0302000 and 2018YFA0306201)the National Natural Science Foundation of China(11774063,11727811,and 91963212)supported by the Science and Technology Commission of Shanghai Municipality(19XD1434600,2019SHZDZX01 and 19DZ2253000)。
文摘The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions EepT. EepT describes the relation between energy E and momentum p of photonic eigenmodes, and essentially determines the optical properties of materials. As EepT is defined in momentum space(k-space), the experimental method to detect the energy distribution, that is the spectrum, in a momentum-resolved manner is highly required. In this review, the momentum-space imaging spectroscopy(MSIS) system is presented, which can directly study the spectral information in momentum space. Using the MSIS system, the photonic dispersion can be captured in one shot with high energy and momentum resolution. From the experimental momentumresolved spectrum data, other key features of photonic eigenmodes, such as quality factors and polarization states, can also be extracted through the post-processing algorithm based on the coupled mode theory. In addition, the interference configurations of the MSIS system enable the measurement of coherence properties and phase information of nanophotonic materials, which is important for the study of light-matter interaction and beam shaping with nanostructures. The MSIS system can give the comprehensive information of nanophotonic materials, and is greatly useful for the study of novel photonic phenomena and the development of nanophotonic technologies.
基金supported by Taishan Scholars Project Special Funds(tsqn201812083)the Natural Science Foundation of Shandong Province(ZR2019YQ20,ZR2019BEM022,and 2019JMRH0410)the National Natural Science Foundation of China(51972147)。
文摘The nanoscale effect enables the unique magnetic,optical,thermal and electrical properties of nanostructured materials and has attracted extensive investigation for applications in catalysis,biomedicine,sensors,and energy storage and conversion.The widely used synthesis methods,such as traditional hydrothermal reaction and calcination,are bulk heating processes based on thermal radiation.Differing from traditional heating methods,non-thermal radiation heating technique is a local heating mode.In this regard,this review summarizes various non-thermal radiation heating methods for synthesis of nanomaterials,including microwave heating,induction heating,Joule heating,laser heating and electron beam heating.The advantages and disadvantages of these non-thermal radiation heating methods for the synthesis of nanomaterials are compared and discussed.Finally,the future development and challenges of non-thermal radiation heating method for potential synthesis of nanomaterials are discussed.