Fig. 3
From: Ion exchange: an advanced synthetic method for complex nanoparticles
(Reprinted with permission from Springer Nature Publishing AG [82])
Illustration of the ion diffusion process via vacancies (a) and interstitial sites (b) at the PbS/CdS interfacial site. The blue and red circles represent Pd and Cd, and the pink circle is an interstitial site. These two processes have different activation energies due to the ‘vacancy-mediated’ and ‘kick-out’ mechanism. In this case, Cd ions diffuse through the interstitial site (b) is advantageous in terms of the activation energy