Structural and electronic properties of copper nanowires inside zigzag carbon nanotubes

• A linear [zigzag] Cu chain is preferred inside the (6,0) [(7,0) and (8,0)] CNTs.
• The highest stability and quantum conductance make Cu16@(10,0) a potential application.
• Among all CuN@(n,0), only Cu2@(7,0) has a net magnetic moment of 0.59μB.

We present a systematic study of the structural and electronic properties of CuN@(n,0) (N=1, 2, 4 for n=6, 7, 8 and N=12, 16 for n=10) combined systems using the first-principle calculations. We find that CuNWs encapsulated inside the (6,0) CNTs prefer to form a single linear chain on the tube axis, while those in (7,0) and (8,0) CNTs tend to form a zigzag chain. The smaller formation energies of −2.265 eV for Cu12@(10,0) combined system and −2.271 eV for Cu16@(10,0) combined system indicate that these two systems are more stable than the other systems studied here, and more complex configurations of CuNWs are expected encapsulating into broader CNTs. Besides having high stability, the Cu16@(10,0) combined system with quantum conductance of 3G0 is under the protection of the outer (10,0) CNT from oxidation, thus can be expected to have potential applications in building nanodevices. The asymmetry distribution of the down-spin and up-spin channels results in a net magnetic moment of 0.59μB for the Cu2@(7,0) combined system.