Polarimetric response of magnetodielectric core-shell nanoparticles: an analysis of scattering directionality and sensing Articles uri icon

publication date

  • May 2016

start page

  • 1

end page

  • 9

issue

  • 23

volume

  • 27

International Standard Serial Number (ISSN)

  • 0957-4484

Electronic International Standard Serial Number (EISSN)

  • 1361-6528

abstract

  • The influence of increasing the core size of Ag Si core shell nanoparticles has been investigated by using the values of the linear polarization degree at a right-angle scattering configuration, ${P}_{L}(90^\circ )$. Changes in dipolar resonances and scattering directionality conditions as a function of the core radius (Rint) for a fixed shell size (${R}_{\mathrm{ext}}=230$ nm) have been analysed. An empirical formula to obtain the ratio ${R}_{\mathrm{int}}/{R}_{\mathrm{ext}}$ by monitoring the influence of the magnetic dipolar resonance in ${P}_{L}(90^\circ )$ has been found. The effect of the refractive index of the surrounding medium, mmed, in the zero backward and almost-zero forward scattering conditions has also been studied. We have weighed up the sensitivity of ${P}_{L}(90^\circ )$ to mmed. It has been demonstrated that multipolar contributions strongly influence ${P}_{L}(90^\circ )$. This influence can be used as a fast mmed estimate. In all cases, the results show that the bigger the cores, the higher the sensitivity to mmed.

subjects

  • Electronics
  • Materials science and engineering
  • Physics

keywords

  • nanoparticles; polarization; scattering; core-shell; high refractive index; sensing