Fig. 3. Schematic illustration of the formation of Co-Fe PBA CCs.

(A) Routes for the formation of CC-1 (route I) and CC-2 (route II) with the structural evolution and phase transition. (B) Two pathways toward the orientation of the SNCs for the following attachment. (C) Illustration of the enthalpic valence of NCs and their atomic analogs. (D) Illustration of the entropic valence of NCs.