Fig. 1

Schematic description of layer deposition. a 15 nm of Pd/Au/Ag with 5 nm each layer (tri-layers). b 15 nm of Pd/Au/Ag (15 layers) with 1 nm each (multi-layers). c Pd_{150 nm}/Ag_{80 nm} bi-layer deposition (bi-layers). d–i Evolution of tri-metallic PdAuAg NPs between 400 and 900 °C for 450 s on sapphire (0001). This set is based on the 15 nm of Pd/Au/Ag with 5 nm each layer. d–i AFM top-views (3 × 3 μm²). d-1–i-1 Magnified AFM side views (750 × 750 nm²). d-2–i-2 Cross-sectional line profiles