Synthetic control over lattice strain in trimetallic AuCu-core Pt-shell nanoparticles

-cores, tunable in composition from 0 at% Cu to 77 at% Cu, and monodisperse in size. Subsequent overgrowth results in uniform, epitaxially grown Pt-shells with a controlled thickness of ∼3 atomic layers. By employing a multi-technique characterization strategy combining X-ray diffraction, electron diffraction and aberration corrected electron microscopy, we unravel the atomic structure of the trimetallic system on a single nanoparticle-, ensemble- and bulk scale level, and we unambiguously demonstrate the controlled variation of strain in the Pt-shell from -3.62% compressive-, to +3.79% tensile strain, while retaining full control over all other structural characteristics of the system.