Orientation of core-shell nanoparticles in an electric field

Coated nanoparticles, which have a core-shell structure, have many applications. This letter investigates the induced torque and orientation of such nanoparticles in an electric field. The authors show that the shell of a nanoparticle has an important effect on its orientation, even when the shell is thin and takes only a small portion of the total volume. For lossy dielectric particles, the permittivity, conductivity, field frequency, and core-shell structure together determine the magnitude and direction of the induced torque, suggesting a significant degree of experimental control over nanoparticle rotation and alignment.