Peripheral nitrogen topology as a defect-chemical design parameter for electronic and magnetic states in graphene: a first-principles study of pyridinic, pyridazinic, pyrrolic, and pyrazolic configurations
Year: 2026
Type: article
Abstract: Defect and heteroatom engineering are powerful routes for tuning graphene's electronic and magnetic properties, yet peripheral nitrogen topology around graphene voids remains poorly understood. Using spin-polarized first-principles calculations, we examine four heterocyclic nitrogen configurations, pyridinic, pyridazinic, pyrrolic, and pyrazolic, affecting structure, charge redistribution, electronic states, and magnetism in graphene with a central void. Pyridinic N is energetically most favorable, and nitrogen topology controls local lattice reconstruction, shown by bond-length analysis. Charge-density-difference and Bader analyses show peripheral N atoms act as electron-accumulating centers reshaping the vacancy rim. Pyridinic, pyridazinic, and pyrrolic configurations remain metallic or near metallic, whereas pyrazolic graphene opens a narrow band gap and is spin compensated with zero net magnetization, unlike the finite moments of the other systems. This magnetism traces to N-modulated vacancy-edge states involving N 2p and C 2p orbitals, establishing peripheral nitrogen topology as a metal-free, deterministic defect-chemical switch for spintronic and semiconducting domains.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,870
OpenAlex ID: W7165633949