Zirconium Nitride: Optical Properties of an Emerging Intermetallic for Plasmonic Applications

Finding new plasmonic materials with prominent optical properties and unique physical and chemical characteristics, which are merits of traditional gold and silver, is of great interest to many applications. This work uses a series of powerful numerical methods, such as density functional theory (DFT) and electromagnetic modeling approaches, to predict the plasmonic response of a mechanically well-known material, zirconium nitride (ZrN). DFT first delivers an electronic analysis and optical dispersion data between 1 and 8 eV, experimentally verified in the lower energy regime ( <4 eV ), and extremely valuable for any subsequent optical modeling. Subsequent electromagnetic modeling steps, including the transfer matrix method (TMM) and Mie theory, demonstrate the excitation of surface plasmon polaritons and localized surface plasmon resonances in ZrN thin films and nanoparticles. Furthermore, the finite-difference time-domain (FDTD) method exhibits the excitation of distinct electric (plasmon) and magnetic (LC) resonances in a periodic array of u-shaped ZrN split-ring resonators (SRRs). The findings showcase an optical behavior comparable with structures made from noble metals such as gold and silver and support the introduction of ZrN as a new and appropriate candidate for plasmonic applications, specifically in technological applications where optical and mechanical properties are of simultaneous concern.