Magneto-Plasmonic Nanoparticles
01 Jan 2021-Vol. 308, pp 107-136
TL;DR: Magnetoplasmonic nanoparticles encompass in a single nano-entity all the rich science and promising applications of the plasmonics and magnetic nanoworlds as discussed by the authors, and they are excellent benchmark materials to develop and investigate multiresponsive multifunctional nanosystems that now are required in an increasing number of technologies, such as biomedicine, pharmacy, catalysis, optoelectronics and data storage.
Abstract: Magnetoplasmonics nanoparticles encompass in a single nano-entity all the rich science and promising applications of the plasmonics and magnetic nanoworlds. The difficult liaison and a certain incompatibility between plasmonics and magnetic phenomena, due to the different chemical-physical origins and supporting materials, are overcome thanks to the design and synthesis of novel nanostructures. The variations of properties, interactions and synergies of both phenomena and materials demonstrate how rich and surprising the matter is at nanoscale and the promising applications. In fact, we show how not only light and magnetism can interplay but also other phenomena like forces, heat, electric field and chemical interactions, between others, can show synergism. Magnetoplasmonic systems are excellent benchmark materials to develop and investigate multi-responsive multifunctional nanosystems that now are required in an increasing number of technologies, such as biomedicine, pharmacy, catalysis, optoelectronics and data storage.
Citations
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TL;DR: In this paper, the authors use localized surface plasmon resonances to couple light to nanomagnets and achieve significantly higher opto-magnetic field values in comparison to free space light excitation.
Abstract: The demand for faster magnetization switching speeds and lower energy consumption has driven the field of spintronics in recent years. The magnetic tunnel junction is the most developed spintronic memory device in which the magnetization of the storage layer is switched by spin-transfer-torque or spin-orbit torque interactions. Whereas these novel spin-torque interactions exemplify the potential of electron-spin-based devices and memory, the switching speed is limited to the ns regime by the precessional motion of the magnetization. All-optical magnetization switching, based on the inverse Faraday effect, has been shown to be an attractive method for achieving magnetization switching at ps speeds. Successful magnetization reversal in thin films has been demonstrated by using circularly polarized light. However, a method for all-optical switching of on-chip nanomagnets in high density memory modules has not been described. In this work we propose to use plasmonics, with CMOS compatible plasmonic materials, to achieve on-chip magnetization reversal in nanomagnets. Plasmonics allows light to be confined in dimensions much smaller than the diffraction limit of light. This in turn, yields higher localized electromagnetic field intensities. In this work, through simulations, we show that using localized surface plasmon resonances, it is possible to couple light to nanomagnets and achieve significantly higher opto-magnetic field values in comparison to free space light excitation.
15 citations
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TL;DR: In this article , a large magnetoplasmonic response of silver nanoparticles was demonstrated by performing magnetic circular dichroism spectroscopy at high magnetic fields, revealing a linear response to the magnetic field up to 30 T.
Abstract: Tuning the plasmonic response with an external magnetic field is extremely promising to achieve active magnetoplasmonic devices, such as next generation refractometric sensors or tunable optical components. Noble metal nanostructures represent an ideal platform for studying and modeling magnetoplasmonic effects through the interaction of free electrons with external magnetic fields, even though their response is relatively low at the magnetic field intensities commonly applied in standard magneto-optical spectroscopies. Here we demonstrate a large magnetoplasmonic response of silver nanoparticles by performing magnetic circular dichroism spectroscopy at high magnetic fields, revealing a linear response to the magnetic field up to 30 T. The exploitation of such high fields allowed us to probe directly the field-induced splitting of circular plasmonic modes by performing absorption spectra with static circular polarizations, giving direct experimental evidence that the magneto-optical activity of plasmonic nanoparticles arises from the energy shift of field-split circular magnetoplasmonic modes.
7 citations
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TL;DR: In this paper, magnetic circular dichroism (MCD) spectroscopy was used to investigate magnetoplasmonic responses in higher-order multipolar (quadrupolar and octupolar) modes of Ag nanoparticles.
Abstract: Characteristic features of magnetoplasmonic responses in higher-order multipolar (quadrupolar and octupolar) modes of Ag nanoparticles (from 90 to 200 nm in diameter) are demonstrated for the first time using magnetic circular dichroism (MCD) spectroscopy. In optical extinction spectra, with an increase in the size of the nanoparticles, the red shift of dipolar plasmon peaks and the appearance of higher-order multipolar resonances can reasonably be observed. Aside from the dipolar and quadrupolar modes, the octupolar plasmonic extinction is very weak and almost unresolved. In contrast, strikingly, MCD shows a very sharp and intense peak (or valley) for the octupolar resonance, meaning its unique properties with high sensitivity and enhanced spectral resolution. MCD responses assignable to the quadrupolar mode have a distinct derivative-like shape, which is different from those observed for Ag nanocubes and nanodecahedra in our previous studies. We then discuss this behavior from the viewpoint of size and/or polyhedral shape inhomogeneity.
4 citations
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TL;DR: Extended Mie theory for multilayer particles is used to examine the individual effects of the real and imaginary components of core refractive indices on Au-shell NP plasmonic peaks and shows that the addition of a nonabsorbing polymer layer to the core surface decreases the dampening of the cavity plAsmon and increases LSPR spectral intensity.
Abstract: Gold-coated iron oxide core–shell nanoparticles (IO-Au NPs) are of interest for use in numerous biomedical applications because of their unique combined magnetic–plasmonic properties. Although the effects of the core-dielectric constant on the localized surface plasmon resonance (LSPR) peak position of Au-shell particles have been previously investigated, the impact that light-absorbing core materials with complex dielectric functions have on the LSPR peak is not well established. In this study, we use extended Mie theory for multilayer particles to examine the individual effects of the real and imaginary components of core refractive indices on Au-shell NP plasmonic peaks. We find that the imaginary component dampens the intensity of the cavity plasmon and results in a decrease of surface plasmon coupling. For core materials with large imaginary refractive indices, the coupled mode LSPR peak disappears, and only the anticoupled mode remains. Our findings show that the addition of a nonabsorbing polymer layer to the core surface decreases the dampening of the cavity plasmon and increases LSPR spectral intensity. Additionally, we address apparent discrepancies in the literature regarding the effects of Au-shell thickness on LSPR peak shifts.
References
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TL;DR: In this paper, the optical constants for the noble metals (copper, silver, and gold) from reflection and transmission measurements on vacuum-evaporated thin films at room temperature, in the spectral range 0.5-6.5 eV.
Abstract: The optical constants $n$ and $k$ were obtained for the noble metals (copper, silver, and gold) from reflection and transmission measurements on vacuum-evaporated thin films at room temperature, in the spectral range 0.5-6.5 eV. The film-thickness range was 185-500 \AA{}. Three optical measurements were inverted to obtain the film thickness $d$ as well as $n$ and $k$. The estimated error in $d$ was \ifmmode\pm\else\textpm\fi{} 2 \AA{}, and that in $n$, $k$ was less than 0.02 over most of the spectral range. The results in the film-thickness range 250-500 \AA{} were independent of thickness, and were unchanged after vacuum annealing or aging in air. The free-electron optical effective masses and relaxation times derived from the results in the near infrared agree satisfactorily with previous values. The interband contribution to the imaginary part of the dielectric constant was obtained by subtracting the free-electron contribution. Some recent theoretical calculations are compared with the results for copper and gold. In addition, some other recent experiments are critically compared with our results.
17,509 citations
•
15 May 2007
TL;DR: In this paper, the authors discuss the role of surface plasmon polaritons at metal/insulator interfaces and their application in the propagation of surfaceplasmon waveguides.
Abstract: Fundamentals of Plasmonics.- Electromagnetics of Metals.- Surface Plasmon Polaritons at Metal / Insulator Interfaces.- Excitation of Surface Plasmon Polaritons at Planar Interfaces.- Imaging Surface Plasmon Polariton Propagation.- Localized Surface Plasmons.- Electromagnetic Surface Modes at Low Frequencies.- Applications.- Plasmon Waveguides.- Transmission of Radiation Through Apertures and Films.- Enhancement of Emissive Processes and Nonlinearities.- Spectroscopy and Sensing.- Metamaterials and Imaging with Surface Plasmon Polaritons.- Concluding Remarks.
7,238 citations
•
05 Oct 2014
TL;DR: In this paper, the authors present a survey of optical spectra of Elemental Metal Clusters and Chain Aggregates and discuss experimental results and experimental methods for metal clustering experiments.
Abstract: 1. Introduction.- 2. Theoretical Considerations.- 3. Experimental Methods.- 4. Experimental Results and Discussion.- A.1 Tables: Optical Spectroscopy Experiments with Metal Clusters.- A.2 Survey of Optical Spectra of Elemental Metal Clusters and Chain-Aggregates.- A.3 Mie Computer Program.- References.
6,405 citations
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TL;DR: The basic concepts behind plasmonics-enabled light concentration and manipulation are discussed, an attempt to capture the wide range of activities and excitement in this area is made, and possible future directions are speculated on.
Abstract: The unprecedented ability of nanometallic (that is, plasmonic) structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavours. Plasmonic light concentrators can elegantly interface diffraction-limited dielectric optical components with nanophotonic structures. Passive and active plasmonic devices provide new pathways to generate, guide, modulate and detect light with structures that are similar in size to state-of-the-art electronic devices. With the ability to produce highly confined optical fields, the conventional rules for light-matter interactions need to be re-examined, and researchers are venturing into new regimes of optical physics. In this review we will discuss the basic concepts behind plasmonics-enabled light concentration and manipulation, make an attempt to capture the wide range of activities and excitement in this area, and speculate on possible future directions.
3,953 citations
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TL;DR: In this article, the authors summarized the basic principles and major achievements of plasmon guiding, and details the current state-of-the-art in subwavelength PLASmonic waveguides, passive and active nanoplasmonic components for the generation, manipulation and detection of radiation, and configurations for the nanofocusing of light.
Abstract: Recent years have seen a rapid expansion of research into nanophotonics based on surface plasmon–polaritons. These electromagnetic waves propagate along metal–dielectric interfaces and can be guided by metallic nanostructures beyond the diffraction limit. This remarkable capability has unique prospects for the design of highly integrated photonic signal-processing systems, nanoresolution optical imaging techniques and sensors. This Review summarizes the basic principles and major achievements of plasmon guiding, and details the current state-of-the-art in subwavelength plasmonic waveguides, passive and active nanoplasmonic components for the generation, manipulation and detection of radiation, and configurations for the nanofocusing of light. Potential future developments and applications of nanophotonic devices and circuits are also discussed, such as in optical signals processing, nanoscale optical devices and near-field microscopy with nanoscale resolution.
3,481 citations