Figure 2.

(a–e) Manifestation of colour changes that occurred during the synthesis of Co-cores indicating different stages of the reaction; (a) precursor solution, (b) after the addition of reducing and stabilizing agents, (c–e) upon heating the solution up to 195°C. (f) Demonstration of different colours of final colloidal samples; (S0) no silver content, (S1) 0.01 g silver content, (S2) 0.1 g Silver content and (S3) 0.2 g silver content.