Optical properties of magnesium nanorods using time dependent density functional theory calculations.

Abstract

Plasmonic nanostructures made of Earth-abundant and low-cost metals such as aluminum and magnesium have recently emerged as a potential alternative candidate to conventional plasmonic metals such as gold and silver. Here using computationally efficient time-dependent density-functional theory calculations, we explore optical response modulations of magnesium nanorods via aspect ratio and absolute size variations. We reveal that both the aspect ratio and absolute size of the nanorods are critical for elucidating their optical characteristics. We show that both tuning factors cause significant optical response modulations in the case of thin nanorods (emergence of localized surface plasmon resonances, significant spectral shifting and spectral intensity re-distributions), whereas, very marginal changes in the case of thick nanorods. We believe that our theoretical results would help in the design of magnesium based nano-plasmonic devices.