Fig. 20
From: Recent advances in chiral nanomaterials with unique electric and magnetic properties
Reproduced with permission from [122]
a Schematic of the fabrication of NP/metal bilayer metamaterials. b– d Representative SEM images of 3D metamaterials after. e Overlaid SEM images of meta-atoms; before annealing (black), annealing at 160 °C for 5 min (blue) and 60 min (red). f Extinction cross-sections for NP/metal metamaterials with varying R. Reproduced with permission from [120]. g Relation between resonance peak and the radius. The inset shows the shift of the resonance peak position. The black data points indicate samples before annealing and red, orange, and blue data points represent samples after annealing at 150, 120, and 90 °C for 24 h, respectively.