One-dimensional(1D)metals are highly conductive and tend to form networks that facilitate electron hopping and migration.Hence,they have tremendous potential as microwave-absorbing(MA)materials.Traditionally,1D metals...One-dimensional(1D)metals are highly conductive and tend to form networks that facilitate electron hopping and migration.Hence,they have tremendous potential as microwave-absorbing(MA)materials.Traditionally,1D metals are mainly precious metals such as gold,silver,nickel,and their preparation methods often have low yield and are not environmentally friendly,which has limited the exploration in this area.Herein,the unique nanolaminate structure and chemical bond characteristics of Ti_(2)SnC MAX phase is successfully taken advantages for large-scale preparation of Sn whiskers,and then,core-sheath Sn/SnO_(x)heterojunctions are obtained by simply annealing at different temperatures.The heterojunction annealed at 500℃possesses favorable MA performance with an effective absorption bandwidth of 5.3 GHz(only 1.7 mm)and a minimum reflection loss value of51.97 dB;its maximum radar cross section(RCS)reduction value is 29.59 dB·m^(2),confirming its excellent electromagnetic wave attenuation ability.Off-axis electron holography is used to visually characterize the distribution of charge density at the cylindrical heterogenous interface,confirming the enhanced interfacial polarization effect.Given the diversity of MAX phases and the advantages of the fabrication method(e.g.,green,inexpensive,and easily scalable),this work provides significant guidance for the design of 1D metal-based absorbers.展开更多
基金supported by the National Natural Science Foundation of China(52171033)the Natural Science Foundation of Jiangsu Province(BK20201283).
文摘One-dimensional(1D)metals are highly conductive and tend to form networks that facilitate electron hopping and migration.Hence,they have tremendous potential as microwave-absorbing(MA)materials.Traditionally,1D metals are mainly precious metals such as gold,silver,nickel,and their preparation methods often have low yield and are not environmentally friendly,which has limited the exploration in this area.Herein,the unique nanolaminate structure and chemical bond characteristics of Ti_(2)SnC MAX phase is successfully taken advantages for large-scale preparation of Sn whiskers,and then,core-sheath Sn/SnO_(x)heterojunctions are obtained by simply annealing at different temperatures.The heterojunction annealed at 500℃possesses favorable MA performance with an effective absorption bandwidth of 5.3 GHz(only 1.7 mm)and a minimum reflection loss value of51.97 dB;its maximum radar cross section(RCS)reduction value is 29.59 dB·m^(2),confirming its excellent electromagnetic wave attenuation ability.Off-axis electron holography is used to visually characterize the distribution of charge density at the cylindrical heterogenous interface,confirming the enhanced interfacial polarization effect.Given the diversity of MAX phases and the advantages of the fabrication method(e.g.,green,inexpensive,and easily scalable),this work provides significant guidance for the design of 1D metal-based absorbers.
