Electronic and magnetic properties of single-wall GeC nanotubes filled with iron nanowires

► The initial shape of Fe21@(8, 8) system distort largely. ► Pristine (8, 8) GeCNT is nonmagnetic direct semiconductor with a wide band gap of 2.65 eV. ► Separation between bonding and antibonding d states is reduced as going from core to outer Fe atom. ► Spin polarization decreases with increasing n for Fen@(8, 8) and Fen systems. ► The magnetism is mainly confined within the inner Fe nanowire for these combined systems.