Crystallographic investigation of Au nanoparticles embedded in a SrTiO${}_3$ thin film for plasmonics applications by means of synchrotron radiation

Abstract

Self-organized monocrystalline Au nanoparticles with potential applications in plasmonics are grown in a SrTiO${}_3$ matrix by a novel two-step deposition process. The crystalline preferred orientation of these Au nanoparticles is investigated by synchrotron hard x-ray diffraction. Nanoparticles preferentially align with the (111) direction along the substrate normal (001), whereas two in-plane orientations are found with $[110{]}_{SrTi{O}_3}||[110{]}_{Au}$ and $[100{]}_{SrTi{O}_3}||[110{]}_{Au}$. Additionally, a smaller diffraction signal from nanoparticles with the (001) direction parallel to the substrate normal (001) is observed; once again, two in-plane orientations are found, with $[100{]}_{SrTi{O}_3}||[100{]}_{Au}$ and $[100{]}_{SrTi{O}_3}||[110{]}_{Au}$. The populations of the two in-plane orientations are found to depend on the thickness of the gold film deposited in the first step of the growth.

10 pages, 13 figures