The influences of polarization direction, incidence angle, and geometry on near-field enhancements in two-layered gold nanowires （TGNWs） have been investigated by using the vector wave function method. When the pola...The influences of polarization direction, incidence angle, and geometry on near-field enhancements in two-layered gold nanowires （TGNWs） have been investigated by using the vector wave function method. When the polarization direction is perpendicular to the incidence plane, the local field factor （LFF） in TGNW decreases first and then increases with the increase in the incidence angle. The minimum LFF is observed at an incidence angle of 41°. It is found that the increase in the dielectric constant of the inner core leads to a decrease in the LFF. With the increase in the inner core radius, the LFF in TGNW increases first and then decreases, and the maximum LFF is observed at an inner core radius of 27 nm. On the other hand, when the polarization direction is parallel to the incidence plane, the collective motions of the induced electrons are enhanced gradually with the decrease in the incidence angle, and hence the near-field enhancement is increased.展开更多
Photoinduced effects on the transmission and resistivity in wide-bandwidth manganite La0.7Sr0.3MnO3 films （TC= 350 K） have been investigated at various temperatures in the range of 5-470 K by means of the time-resol...Photoinduced effects on the transmission and resistivity in wide-bandwidth manganite La0.7Sr0.3MnO3 films （TC= 350 K） have been investigated at various temperatures in the range of 5-470 K by means of the time-resolved pump-probe method. Below To, we have observed a negative transmission change ATM/TM at 2.54eV and a positive resistivity change AR/R under photo-irradiation at excited energy Eexc = 3.20 eV. With temperature approaching to To, the values of ATM/TM and AR/R show a significant reduction. We have ascribed the photoinduced changes on the transmission and resistivity of the La0.7Sr0.3MnO3 film to the charge-ordering fluctuation in the ferromagnetic phase, which is similar to that observed in the narrow-bandwidth La0.7Sr0.3MnO3 films.展开更多
The influences of the anisotropy of the outer spherically anisotropic （SA） layer on the far-field spectra and near- field enhancements of the silver nanoshells are investigated by using a modified Mie scattering the...The influences of the anisotropy of the outer spherically anisotropic （SA） layer on the far-field spectra and near- field enhancements of the silver nanoshells are investigated by using a modified Mie scattering theory. It is found that with the increase of the anisotropic value of the SA layer, the dipole resonance wavelength of the silver nanoshell first increases and then decreases, while the local field factor （LFF） reduces. With the decrease of SA layer thickness, the dipole wavelength of the silver nanoshell shows a distinct blue-shift. When the SA layer becomes very thin, the modulations of the anisotropy of the SA layer on the plasmon resonance energy and the near-field enhancement are weakened. We further find that the smaller anisotropic value of the SA layer is helpful for obtaining the larger near-field enhancement in the Ag nanoshell. The geometric average of the dielectric components of the SA layer has a stronger effect on the plasmon resonance energy of the silver nanoshell than on the near-field enhancement.展开更多
We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2...We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2.5140, and V = 136.30A^3）,展开更多
The electric field enhancement properties of an active gold nanoshell with gain material inside have been investigated by using Mie theory. As the gain coefficient of the inner core increases to a critical value, a su...The electric field enhancement properties of an active gold nanoshell with gain material inside have been investigated by using Mie theory. As the gain coefficient of the inner core increases to a critical value, a super-resonance appears in the active gold nanoshell, and enormous enhancements of the electric fields can be found near the surface of the particle. With increasing shell thickness, the critical value of the gain coefficient for the super-resonance of the active gold nanoshell first decreases and then increases, and the corresponding surface enhanced Raman scattering （SERS） enhancement factor （G factor） also first increases and then decreases. The optimized active gold nanoshell can be obtained with an extremely high SERS G factor of the order of 1019-1020. Such an optimized active gold nanoshell possesses a high-efficiency SERS effect and may be useful for single-molecule detection.展开更多
The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. ...The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the e/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1~ Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interracial interaction between the anatase and rutile phases induced by different Ag concentrations.展开更多
We design an asymmetric transmission system(ATS)with two flat acoustic metasurfaces(AMs)to yield bidirectional asymmetric acoustic focusing(BAAF).The acoustic waves could be focused on both sides of the ATS with diffe...We design an asymmetric transmission system(ATS)with two flat acoustic metasurfaces(AMs)to yield bidirectional asymmetric acoustic focusing(BAAF).The acoustic waves could be focused on both sides of the ATS with different focal lengths and intensities.To achieve high intensity energy concentration,the accelerating acoustic beams are selected to realize the BAAF.The working bandwidth of the BAAF based on our ATS could reach ～0.4 k Hz.It is found that by adjusting the distance between two flat AMs,the focal length and intensity of the bidirectional focusing could easily be modulated.Because the distance between two flat AMs is large enough,the BAAF even could be converted into a unidirectional acoustic focusing.The proposed BAAF may find applications in non-destructive evaluation,biomedical imaging and medical diagnosis.展开更多
Nd-doping effects are investigated in TiO_(2)nanoparticles with various annealing temperatures T from 70℃ to 1100℃ by means of x-ray diffraction(XRD)and Raman scattering spectroscopy.XRD results indicate that the sa...Nd-doping effects are investigated in TiO_(2)nanoparticles with various annealing temperatures T from 70℃ to 1100℃ by means of x-ray diffraction(XRD)and Raman scattering spectroscopy.XRD results indicate that the sample shows a rutile phase at 1100℃,which changes to anatase phase at 900℃.With decreasing T down to 300℃,a significant lattice shrink is found,that is,the lattice parameter c is significantly suppressed while the a value shows a gradual decrease.With further decrease of T,the c-value shows an unexpected increase while the a-value keeps a gradual decrease.Thus,a lattice distortion takes place with changing the annealing temperature.In Raman investigation,all the Raman modes for the anatase phase show hardening behaviors with decreasing T in the range 900-300℃,and then the Eg and A1g modes show softening behaviors below 300℃,suggesting the variation of the lattice distortion.The variation of the lattice distortion at different annealing temperatures is ascribed to different depositions of Nd ions on the surface of TiO_(2)nanoparticles.展开更多
Surface plasmons（SPs） in ultraviolet（UV） have attracted a great deal of attention because of their emerging applications in energy resources, environmental protection, and biotechnology. In this article, the diele...Surface plasmons（SPs） in ultraviolet（UV） have attracted a great deal of attention because of their emerging applications in energy resources, environmental protection, and biotechnology. In this article, the dielectric loaded surface plasmon polariton（DLSPP） properties of the Al2O3–Al nanostructure are investigated theoretically. Sharp SP responses can be obtained in deep UV by setting an insulator grating on the aluminum film. It is found that the height of the grating element,the lattice parameter, and the filling factor can all modulate the DLSPPs of the Al2O3–Al nanostructure. We further find that this structure is sensitive to the embedding medium and can serve as a refractive index sensor in the UV region. The corresponding sensitivity increases with the decrease of the filling factor. The Al2O3–Al nanostructure may be useful for medical diagnostics and biotechnology in deep UV.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2012CB921504)the National Natural Science Foundation of China (Grant Nos. 11174113, 10904052, and 11074124)the PAPD of Jiangsu Higher Education Institutions,China
文摘The influences of polarization direction, incidence angle, and geometry on near-field enhancements in two-layered gold nanowires （TGNWs） have been investigated by using the vector wave function method. When the polarization direction is perpendicular to the incidence plane, the local field factor （LFF） in TGNW decreases first and then increases with the increase in the incidence angle. The minimum LFF is observed at an incidence angle of 41°. It is found that the increase in the dielectric constant of the inner core leads to a decrease in the LFF. With the increase in the inner core radius, the LFF in TGNW increases first and then decreases, and the maximum LFF is observed at an inner core radius of 27 nm. On the other hand, when the polarization direction is parallel to the incidence plane, the collective motions of the induced electrons are enhanced gradually with the decrease in the incidence angle, and hence the near-field enhancement is increased.
基金Supported by the National Natural Science Foundation of China under grant No 10374041, the Programme for New Century Excellent Talents in University, the State Education Ministry of China under grant No NECT-04-0456.
文摘Photoinduced effects on the transmission and resistivity in wide-bandwidth manganite La0.7Sr0.3MnO3 films （TC= 350 K） have been investigated at various temperatures in the range of 5-470 K by means of the time-resolved pump-probe method. Below To, we have observed a negative transmission change ATM/TM at 2.54eV and a positive resistivity change AR/R under photo-irradiation at excited energy Eexc = 3.20 eV. With temperature approaching to To, the values of ATM/TM and AR/R show a significant reduction. We have ascribed the photoinduced changes on the transmission and resistivity of the La0.7Sr0.3MnO3 film to the charge-ordering fluctuation in the ferromagnetic phase, which is similar to that observed in the narrow-bandwidth La0.7Sr0.3MnO3 films.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921504)the National Natural Science Foundation of China(Grant Nos.10904052,11174113,and 11104319)+1 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds,China(Grant No.1002075C)the Senior Talent Foundation of Jiangsu University,China(Grant No.09JDG073)
文摘The influences of the anisotropy of the outer spherically anisotropic （SA） layer on the far-field spectra and near- field enhancements of the silver nanoshells are investigated by using a modified Mie scattering theory. It is found that with the increase of the anisotropic value of the SA layer, the dipole resonance wavelength of the silver nanoshell first increases and then decreases, while the local field factor （LFF） reduces. With the decrease of SA layer thickness, the dipole wavelength of the silver nanoshell shows a distinct blue-shift. When the SA layer becomes very thin, the modulations of the anisotropy of the SA layer on the plasmon resonance energy and the near-field enhancement are weakened. We further find that the smaller anisotropic value of the SA layer is helpful for obtaining the larger near-field enhancement in the Ag nanoshell. The geometric average of the dielectric components of the SA layer has a stronger effect on the plasmon resonance energy of the silver nanoshell than on the near-field enhancement.
文摘We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2.5140, and V = 136.30A^3）,
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921504)the National Natural Science Foundation of China(Grant Nos.51306072,11174113,and 11204129)+1 种基金the Qing Lan Project of Jiangsu Province,Chinathe Senior Talent Foundation of Jiangsu University(Grant No.12JDG060)
文摘The electric field enhancement properties of an active gold nanoshell with gain material inside have been investigated by using Mie theory. As the gain coefficient of the inner core increases to a critical value, a super-resonance appears in the active gold nanoshell, and enormous enhancements of the electric fields can be found near the surface of the particle. With increasing shell thickness, the critical value of the gain coefficient for the super-resonance of the active gold nanoshell first decreases and then increases, and the corresponding surface enhanced Raman scattering （SERS） enhancement factor （G factor） also first increases and then decreases. The optimized active gold nanoshell can be obtained with an extremely high SERS G factor of the order of 1019-1020. Such an optimized active gold nanoshell possesses a high-efficiency SERS effect and may be useful for single-molecule detection.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10874088 and 10874087, the Key Project of the Ministry of Education of China under Grant No 107051, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 200802840032, and State Key Laboratory of Electrical Insulation and Power Equipment, Xi＇an Jiaotong University （EIPE09202）.
文摘The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the e/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1~ Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interracial interaction between the anatase and rutile phases induced by different Ag concentrations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11704193,11674175,and 11704192)the "333" Project of Jiangsu Province,China(Grant No.BRA2017451)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX18_1185)
文摘We design an asymmetric transmission system(ATS)with two flat acoustic metasurfaces(AMs)to yield bidirectional asymmetric acoustic focusing(BAAF).The acoustic waves could be focused on both sides of the ATS with different focal lengths and intensities.To achieve high intensity energy concentration,the accelerating acoustic beams are selected to realize the BAAF.The working bandwidth of the BAAF based on our ATS could reach ～0.4 k Hz.It is found that by adjusting the distance between two flat AMs,the focal length and intensity of the bidirectional focusing could easily be modulated.Because the distance between two flat AMs is large enough,the BAAF even could be converted into a unidirectional acoustic focusing.The proposed BAAF may find applications in non-destructive evaluation,biomedical imaging and medical diagnosis.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10874087,11074124 and 10904052,Jiangsu Provincial Natural Science Foundation under Grant No 200921555the China Postdoctoral Science Foundation under Grant No 201003575.
文摘Nd-doping effects are investigated in TiO_(2)nanoparticles with various annealing temperatures T from 70℃ to 1100℃ by means of x-ray diffraction(XRD)and Raman scattering spectroscopy.XRD results indicate that the sample shows a rutile phase at 1100℃,which changes to anatase phase at 900℃.With decreasing T down to 300℃,a significant lattice shrink is found,that is,the lattice parameter c is significantly suppressed while the a value shows a gradual decrease.With further decrease of T,the c-value shows an unexpected increase while the a-value keeps a gradual decrease.Thus,a lattice distortion takes place with changing the annealing temperature.In Raman investigation,all the Raman modes for the anatase phase show hardening behaviors with decreasing T in the range 900-300℃,and then the Eg and A1g modes show softening behaviors below 300℃,suggesting the variation of the lattice distortion.The variation of the lattice distortion at different annealing temperatures is ascribed to different depositions of Nd ions on the surface of TiO_(2)nanoparticles.
基金Project by the National Natural Science Foundation of China(Grant Nos.11674175,51120125001,and 11474166)the Major Project of Natural Science Research for Colleges and Universities in Jiangsu Province,China(Grant No.15KJA140002)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20150562)the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions,China
文摘Surface plasmons（SPs） in ultraviolet（UV） have attracted a great deal of attention because of their emerging applications in energy resources, environmental protection, and biotechnology. In this article, the dielectric loaded surface plasmon polariton（DLSPP） properties of the Al2O3–Al nanostructure are investigated theoretically. Sharp SP responses can be obtained in deep UV by setting an insulator grating on the aluminum film. It is found that the height of the grating element,the lattice parameter, and the filling factor can all modulate the DLSPPs of the Al2O3–Al nanostructure. We further find that this structure is sensitive to the embedding medium and can serve as a refractive index sensor in the UV region. The corresponding sensitivity increases with the decrease of the filling factor. The Al2O3–Al nanostructure may be useful for medical diagnostics and biotechnology in deep UV.
