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The optical properties of 4 liquid metals Ga, Hg, Cs and Rb are calculated in core-shell bimetallic nanoparticles system over size parameters. The localized surface plasmon resonance (LSPR) of liquid and noble metal for different sizes and shell thickness are effectively tuned over electromagnetic spectrum. In addition, by using Mie Theory size is optimized in terms of structural parameters. The optical frequencies of these core-shell nanostructures are observed to be shifting in UV-Visible-NIR region with enhanced optical efficiencies. Two LSPR peaks are observed for Hg@Au core-shell nanoparticles in UV and Visible region simultaneously. For Cs and Rb almost same plasmonic response is observed, however efficiencies of Rb are better than all other nanoparticles. The calculated absorption and scattering efficiencies of all different compositions for respective applications are discussed. [ABSTRACT FROM AUTHOR]

The multimetallic nanostructures of a noble metal such as gold, silver, and copper have attracted great attention in alloys and core-shell configuration due to the enhanced plasmonic effect. In this theoretical study, the optical properties of bare NiFe and NiFe@Au core-shell NPs have been calculated using extended Mie theory. The core-size of nanostructures is considered 5 nm to 25 nm and shell thickness systematically varied as 3, 5, 7 and 10 nm. It is observed that the localized surface plasmon resonance peaks are red-shifted with increasing shell thickness and blue-shifted with increasing core-sizes. Further, broadening in LSPR peaks is found, as the size of core-NiFe NPs increased and optical efficiency increases with Au-shell thickness. The LSPR peaks at λmax show the absorption spectra in the range of 508-541 nm wavelengths and hence, absorption peaks are found in the visible region. In addition, LSPR peaks of NiFe (permalloy) coated with Au NPs are influenced by changing the refractive index of the embedded medium. Hence, the optical response of NiFe coated with Au nanospheres can be tuned and controlled in the visible region of the electromagnetic spectrum. From the results, it is revealed that varying either NiFe-core or Au-shell thickness and embedded medium could result in obtaining tunable light absorption in UV-visible and may find application in optical imaging, sensing, medical, and novel functional and biomagnetic devices. [ABSTRACT FROM AUTHOR]

We here investigate the optical properties of liquid metal nanosphere for its potential use in plasmonic applications. Due to liquid state and reactivity its efficiency is limited to a narrow range of spectra. The liquid core is coated with noble metal (Silver) to provide stability and broadband plasmonic properties. We discuss theoretically localized surface plasmon resonance (LSPR) peak, absorption and scattering efficiencies using Mie theory. The influence of core size and shell thickness on optical spectra of core-shell nanoparticle shows shifting of peak positions from NIR to Visible region of EM spectrum with increasing size. The enhancement in scattering efficiencies is also observed. These results can be useful for applications like soft electronics, sensors, optical imaging etc. [ABSTRACT FROM AUTHOR]

Research interest is on liquid mercury nanoparticles to show plasmonic response for the purpose of their use in plasmonic applications. The liquid metal mercury is having many applications in like high intensity discharge lamps, electrical switches etc is presently studied by using Mie theory for its LSPR based optical properties with noble metal Ag in the form of core-shell nanostructures. The simultaneous two dipole resonance peaks shown by Hg@Ag nanospheres offers unique properties which can have interesting applications. The calculated optical frequencies are found in UV-visible region of EM spectrum. [ABSTRACT FROM AUTHOR]

Compatibility problems with electronic processes, limited availability and the high cost of noble metals motivate towards the search of alternative materials to enhance the suitability and efficiency of plasmonic based devices. Alloy or coated bimetallic material configuration is an attractive way to engineer a system possessing tuneable plasmonic properties. Magneto-plasmonic nanoparticles (MPNPs) present the possibility to exhibit their tuneable magnetic and optical properties with extensive applications. We studied the optical properties of Ag-Fe alloy for different compositions. The Localised Surface Plasmon Resonance (LSPR) tunability of Agx-Fe1-x (x = 0.25, 0.50 and 0.75) alloy for nanospheres has been calculated by using Discrete Dipole Approximation (DDA) simulation technique. It is found that absorption and scattering efficiencies of Ag-Fe alloy are found in near ultra violet and visible region of electromagnetic spectrum. Large LSPR shift has been observed in absorption and scattering efficiencies peak for 40 nm and 80 nm size of nanospheres alloys. It is concluded that the LSPR can be tuned by changing nanoparticle size and the alloy composition. Results of the plasmonics properties for Ag-Fe alloy at wavelength 330-545nm (absorption) and 331-507nm (scattering) will open the avenues for new applications in optical imaging, biomedical fields particularly in (calorimetric)-DNA, pentose’s, proteins (absorption) and plasmonic-enhanced spectroscopies/spectrometer devices (scattering) for determination of optical densities of cell cultures. [ABSTRACT FROM AUTHOR]