Fe-Cr ferritic/martensitic(F/M)steels have been proposed as one of the candidate materials for the Generation IV nuclear technologies.In this study,a widely-used ferritic/martensitic steel,T91 steel,was irradiated by ...Fe-Cr ferritic/martensitic(F/M)steels have been proposed as one of the candidate materials for the Generation IV nuclear technologies.In this study,a widely-used ferritic/martensitic steel,T91 steel,was irradiated by 196-MeV Kr^(+)ions at 550℃.To reveal the irradiation mechanism,the microstructure evolution of irradiated T91 steel was studied in details by transmission electron microscope(TEM).With increasing dose,the defects gradually changed from black dots to dislocation loops,and further to form dislocation walls near grain boundaries due to the production of a large number of dislocations.When many dislocation loops of primary a0/2<111>type with high migration interacted with other defects or carbon atoms,it led to the production of dislocation segments and other dislocation loops of a0<100>type.Lots of defects accumulated near grain boundaries in the irradiated area,especially in the high-dose area.The grain boundaries of martensite laths acted as important sinks of irradiation defects in T91.Elevated temperature facilitated the migration of defects,leading to the accumulation of defects near the grain boundaries of martensite laths.展开更多
We report the conductance and average current through a triple-quantum-dot interferometer coupled with two ferromagnetic leads using the nonequilibrium Green’s function.The results show that the interference between ...We report the conductance and average current through a triple-quantum-dot interferometer coupled with two ferromagnetic leads using the nonequilibrium Green’s function.The results show that the interference between the resonant process and the non-resonant process leads to the formation of Fano resonance.More Fano resonances can be observed by applying a time-dependent external field.As a Zeeman magnetic field is applied,the spin-up electron transport is depressed in a certain range of electron energy levels.A spin-polarized pulse device can be realized by adjusting the spin polarization parameters of ferromagnetic leads.Moreover,the I–V characteristic curves show that under the influence of Fano resonance,the spin polarization is significantly enhanced by applying a relatively large reverse bias voltage.These results strongly suggest that the spin-polarized pulse device can be potentially applied as a spin-dependent quantum device.展开更多
基金Project supported by Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302011)the National Natural Science Foundation of China(Grant Nos.U2032143,11902370,and 52005523)+2 种基金the International Science and Technology Cooperation Program of Guangdong Province,China(Grant No.2019A050510022)the China Postdoctoral Science Foundation(Grant Nos.2019M653173 and 2019TQ0374)the Heavy Ion Research Facility of Lanzhou(HIRFL).
文摘Fe-Cr ferritic/martensitic(F/M)steels have been proposed as one of the candidate materials for the Generation IV nuclear technologies.In this study,a widely-used ferritic/martensitic steel,T91 steel,was irradiated by 196-MeV Kr^(+)ions at 550℃.To reveal the irradiation mechanism,the microstructure evolution of irradiated T91 steel was studied in details by transmission electron microscope(TEM).With increasing dose,the defects gradually changed from black dots to dislocation loops,and further to form dislocation walls near grain boundaries due to the production of a large number of dislocations.When many dislocation loops of primary a0/2<111>type with high migration interacted with other defects or carbon atoms,it led to the production of dislocation segments and other dislocation loops of a0<100>type.Lots of defects accumulated near grain boundaries in the irradiated area,especially in the high-dose area.The grain boundaries of martensite laths acted as important sinks of irradiation defects in T91.Elevated temperature facilitated the migration of defects,leading to the accumulation of defects near the grain boundaries of martensite laths.
基金the National Natural Science Foundation of China(Grant No.11447132)the“Chunhui Plan”Cooperative Scientific Research Project of China(Grant No.6101020101)the Science and Technology Research Program of Chongqing Education Commission of China(Grant No.KJQN201801402)。
文摘We report the conductance and average current through a triple-quantum-dot interferometer coupled with two ferromagnetic leads using the nonequilibrium Green’s function.The results show that the interference between the resonant process and the non-resonant process leads to the formation of Fano resonance.More Fano resonances can be observed by applying a time-dependent external field.As a Zeeman magnetic field is applied,the spin-up electron transport is depressed in a certain range of electron energy levels.A spin-polarized pulse device can be realized by adjusting the spin polarization parameters of ferromagnetic leads.Moreover,the I–V characteristic curves show that under the influence of Fano resonance,the spin polarization is significantly enhanced by applying a relatively large reverse bias voltage.These results strongly suggest that the spin-polarized pulse device can be potentially applied as a spin-dependent quantum device.
