RESUMO
The controlled growth and stability of transition metal clusters on N-doped materials have become the subject of intense investigation for unveiling comprehension on the cluster growth evolution. In this study, we investigated the growth mechanisms of non-magnetic (copper) and magnetic (iron) clusters on graphene with two atomic vacancies, with and without pyridinic nitrogen (N). Our results determine the role of pyridinic N in the growth and physicochemical properties of the mentioned metal clusters. In an N environment, Cu grows perpendicularly, whereas under N-deficient conditions, the clusters agglomerate. Fe cumulate-type clusters are formed regardless of the presence of N. However, N causes the Fe clusters to rise over one side of the surface without deforming the monolayer; meanwhile, in the absence of N, the Fe clusters protrude from both sides of the monolayer. Remarkably, the presence of N makes it feasible to induce magnetization in the Cun-N4V2 systems and aid in focalizing the magnetic properties on the Fe clusters for the Fen-N4V2 case. These findings offer insights into the role of N in cluster growth, with potential implications for diverse applications, including magnetic and electrocatalytic materials.
RESUMO
The electronic transport properties of ordered networks using carbon nanotubes as building blocks (ON-CNTs) are investigated within the framework of a multiterminal Landauer-Buttiker formalism using an s,p(x),p(y),p(z) parameterization of the tight-binding Hamiltonian for carbon. The networks exhibit electron pathway selectiveness, which is shown to depend on the atomic structure of the network nodes imposed by the specific architecture of the network and the distribution of its defects (non-hexagonal rings). This work represents the first understandings towards leading current through well-defined trajectories along an organic nanocircuit.