共查询到20条相似文献,搜索用时 15 毫秒
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Antonio Bianconi 《Journal of Superconductivity and Novel Magnetism》2013,26(9):2821-2827
The emerging scenario of superstripes for high temperature superconductors is presented. The complexity of the electronic structure of doped cuprates results from two electronic components and nanoscale phase separation. In this lattice, charge and magnetic complexity the unconventional high temperature superconductivity emerges in a broken symmetry. Shape resonances in superconducting gaps are discussed. 相似文献
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María de la Mata Sergio Cataln‐Gmez Flavio Nucciarelli Jos L. Pau Sergio I. Molina 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(43)
Plasmonics has emerged as an attractive field driving the development of optical systems in order to control and exploit light–matter interactions. The increasing interest around plasmonic systems is pushing the research of alternative plasmonic materials, spreading the operability range from IR to UV. Within this context, gallium appears as an ideal candidate, potentially active within a broad spectral range (UV–VIS–IR), whose optical properties are scarcely reported. Importantly, the smart design of active plasmonic materials requires their characterization at high spatial and spectral resolution to access the optical fingerprint of individual nanostructures, attainable by transmission electron microscopy techniques (i.e., by means of electron energy‐loss spectroscopy, EELS). Therefore, the optical response of individual Ga nanoparticles (NPs) by means of EELS measurements is analyzed, in order to spread the understanding of the plasmonic response of Ga NPs. The results show that single Ga NPs may support several plasmon modes, whose nature is extensively discussed. 相似文献
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Fabricating a Homogeneously Alloyed AuAg Shell on Au Nanorods to Achieve Strong,Stable, and Tunable Surface Plasmon Resonances 下载免费PDF全文
Jianfeng Huang Yihan Zhu Changxu Liu Yunfeng Zhao Zhaohui Liu Mohamed Nejib Hedhili Andrea Fratalocchi Yu Han 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(39):5214-5221
Colloidal metal nanocrystals with strong, stable, and tunable localized surface plasmon resonances (SPRs) can be useful in a corrosive environment for many applications including field‐enhanced spectroscopies, plasmon‐mediated catalysis, etc. Here, a new synthetic strategy is reported that enables the epitaxial growth of a homogeneously alloyed AuAg shell on Au nanorod seeds, circumventing the phase segregation of Au and Ag encountered in conventional synthesis. The resulting core–shell structured bimetallic nanorods (AuNR@AuAg) have well‐mixed Au and Ag atoms in their shell without discernible domains. This degree of mixing allows AuNR@AuAg to combine the high stability of Au with the superior plasmonic activity of Ag, thus outperforming seemingly similar nanostructures with monometallic shells (e.g., Ag‐coated Au NRs (AuNR@Ag) and Au‐coated Au NRs (AuNR@Au)). AuNR@AuAg is comparable to AuNR@Ag in plasmonic activity, but that it is markedly more stable toward oxidative treatment. Specifically, AuNR@AuAg and AuNR@Ag exhibit similarly strong signals in surface‐enhanced Raman spectroscopy that are some 30‐fold higher than that of AuNR@Au. When incubated with a H2O2 solution (0.5 m ), the plasmonic activity of AuNR@Ag immediately and severely decayed, whereas AuNR@AuAg retained its activity intact. Moreover, the longitudinal SPR frequency of AuNR@AuAg can be tuned throughout the red wavelengths (≈620–690 nm) by controlling the thickness of the AuAg alloy shell. The synthetic strategy is versatile to fabricate AuAg alloyed shells on different shaped Au, with prospects for new possibilities in the synthesis and application of plasmonic nanocrystals. 相似文献
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Alessandro Marchetti Alessandro Gori Anna Maria Ferretti Daniel Arenas Esteban Sara Bals Claudia Pigliacelli Pierangelo Metrangolo 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(12):2206712
Out-of-equilibrium self-assembly of metal nanoparticles (NPs) has been devised using different types of strategies and fuels, but achieving finite 3D structures with a controlled morphology through this assembly mode is still rare. Here, a spherical peptide-gold superstructure (PAuSS) is used as a template to control the out-of-equilibrium self-assembly of Au NPs, obtaining a transient 3D-branched Au-nanoshell (BAuNS) stabilized by sodium dodecyl sulphate (SDS). The BAuNS dismantles upon SDS concentration gradient equilibration over time in the sample solution, leading to NPs disassembly and regression to PAuSS. Notably, BAuNS assembly and disassembly promotes temporary interparticle plasmonic coupling, leading to reversible and tunable changes of their plasmonic properties, a highly desirable behavior in the development of optoelectronic nanodevices. 相似文献
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Simple and Rapid High‐Yield Synthesis and Size Sorting of Multibranched Hollow Gold Nanoparticles with Highly Tunable NIR Plasmon Resonances 下载免费PDF全文
Adam J. Blanch Markus Döblinger Jessica Rodríguez‐Fernández 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(35):4550-4559
Branched gold nanoparticles with sharp tips are considered excellent candidates for sensing and field enhancement applications. Here, a rapid and simple synthesis strategy is presented that generates highly branched gold nanoparticles with hollow cores and a ca.100% yield through a simple one‐pot seedless reaction at room temperature in the presence of Triton X‐100. It is shown that multibranched hollow gold nanoparticles of tunable dimensions, branch density and branch length can be obtained by adjusting the concentrations of the reactants. Insights into the formation mechanism point toward an aggregative type of growth involving hollow core formation first, and branching thereafter. The pronounced near‐infrared (NIR) plasmon band of the nanoparticles is due to the combined contribution from hollowness and branching, and can be tuned over a wide range (≈700–2000 nm). It is also demonstrated that the high environmental sensitivity of colloidal dispersions based on multibranched hollow gold nanoparticles can be boosted even further by separating the nanoparticles into fractions of given sizes and improved monodispersity by means of a glycerol density gradient. The possibility to obtain highly monodisperse multibranched hollow gold nanoparticles with predictable dimensions (50–300 nm) and branching and, therefore, tailored NIR plasmonic properties, highlights their potential for theranostic applications. 相似文献
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Irina Drachuk Olga Shchepelina Svetlana Harbaugh Nancy Kelley‐Loughnane Morley Stone Vladimir V. Tsukruk 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(18):3128-3137
Natural protein (silk fibroin) nanoshells are assembled on the surface of Saccharomyces cerevisiae yeast cells without compromising their viability. The nanoshells facilitate initial protection of the cells and allow them to function in encapsulated state for some time period, afterwards being completely biodegraded and consumed by the cells. In contrast to a traditional methanol treatment, the gentle ionic treatment suggested here stabilizes the shell silk fibroin structure but does not compromise the viability of the cells, as indicated by the fast response of the encapsulated cells, with an immediate activation by the inducer molecules. Extremely high viability rates (up to 97%) and preserved activity of encapsulated cells are facilitated by cytocompatibility of the natural proteins and the formation of highly porous shells in contrast to traditional polyelectrolyte‐based materials. Moreover, in a high contrast to traditional synthetic shells, the silk proteins are biodegradable and can be consumed by cells at a later stage of growth, thus releasing the cells from their temporary protective capsules. These on‐demand encapsulated cells can be considered a valuable platform for biocompatible and biodegradable cell encapsulation, controlled cell protection in a synthetic environment, transfer to a device environment, and cell implantation followed by biodegradation and consumption of protective protein shells. 相似文献
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《材料科学技术学报》2015,(6)
Semiconductor nanowires(NWs) are sub-wavelength structures which exhibit strong optical(Mie)resonances in the visible range.In addition to such optical resonances,the localized surface plasmon resonances(LSPRs) in metal-semiconductor core-shell(CS) and core-multishell(CMS) NWs can be tailored to achieve novel negative-index metamaterials(N1M),extreme absorbers,invisibility cloaks and sensors.Particularly,in this review,we focus on our recent theoretical studies which highlight the versatility of CS and CMS NWs for:1) the design of negative-index metamaterials in the visible range and2) plasmonic light harvesting in ultrathin photocatalyst layers for water splitting.Utilizing the LSPR in the metal layer and the magnetic dipole(Mie) resonance in the semiconductor shell under transverse electric(TE) polarization,semiconductor-metal-semiconductor CMS NWs can be designed to exhibit spectrally overlapping electric and magnetic resonances in the visible range.NWs exhibiting such double resonances can be considered as meta-atoms and arrayed to form polarization dependent,low-loss NIM.Alternatively,by tuning the LSPR in the TE polarization and the optical resonance in the transverse magnetic(TM) polarization of metal-photocatalyst CS and semiconductor-metal-photocatalyst CMS NWs,the absorption within ultrathin(sub-50 nm) photocatalyst layers can be substantially enhanced.Notably,aluminum and copper based NWs provide absorption enhancement remarkably close to silver and gold based NWs,respectively.Further,such absorption is polarization independent and remains high over a large range of incidence angles and permittivity of the medium.Therefore,due to the tunability of their optical properties,CS and CMS NWs are expected to be vital components for the design of nanophotonic devices. 相似文献
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F. M. Ellis 《Journal of Low Temperature Physics》2004,134(1-2):97-102
There are three independent phenomena that compete to determine the line shapes of third sound resonances in a circular cavity. First, anharmonic terms in the hydrodynamic equations of motion lead to the usual hysteresis on a mugti-valued response function. Second, wave coupling to vortices pinned in the film modify the resonant frequency as changes in the persistent current are induced. Finally, nonlinear dissipation can lead to saturation. The first two of these have been observed to resugt in continuous (not just transient) temporal behavior of the resonance amplitude with a fixed drive. Both cyclical and chaotic behaviors have been observed. The effects are dependent on the ability of the driven wave to either accelerate or decelerate the persistent current onto different amplitude branches of the mugti-valued resonance. 相似文献
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Eric S. A. Goerlitzer Reza Mohammadi Sergey Nechayev Kirsten Volk Marcel Rey Peter Banzer Matthias Karg Nicolas Vogel 《Advanced materials (Deerfield Beach, Fla.)》2020,32(22):2001330
Collective excitation of periodic arrays of metallic nanoparticles by coupling localized surface plasmon resonances to grazing diffraction orders leads to surface lattice resonances with narrow line width. These resonances may find numerous applications in optical sensing and information processing. Here, a new degree of freedom of surface lattice resonances is experimentally investigated by demonstrating handedness-dependent excitation of surface lattice resonances in arrays of chiral plasmonic crescents. The self-assembly of particles used as mask and modified colloidal lithography is applied to produce arrays of planar and 3D gold crescents over large areas. The excitation of surface lattice resonances as a function of the interparticle distance and the degree of order within the arrays is investigated. The chirality of the individual 3D crescents leads to the formation of chiral lattice modes, that is, surface lattice resonances that exhibit optical activity. 相似文献
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