Tuning the spin dependent behavior of monatomic carbon wires between nickel electrodes

• Including the ring structures in linear wires joining nickel electrodes leads to interesting spin dependent properties.
• Spin dependent behavior depends mainly on atomic arrangement of systems.
• Both the spin polarized conductance and magnetic moment are determined by odd–even disparity and depend crucially on inserted ring structures.
• Half-metallicity can be obtained through the ring structures between nickel leads.

Spin polarized Density Functional Theory combined with Non-Equilibrium Greenʼs Function Formalism is applied to investigate the spin dependent transport in carbon based monatomic systems. Both one-dimensional linear and ring structures sandwiched between spin polarized nickel electrodes are examined. Incorporating of nickel electrodes and rings leads to interesting spin dependent properties. The influence of electrode structure is also addressed, using the Ni(100) pyramidal and plane electrodes. It is revealed that spin dependent behavior is largely determined by the atomic arrangement of the monatomic system, and that both the transport and magnetic properties can be tuned by odd–even disparity and/or appropriate ring(s). The mechanisms governing the spin dependent properties in these structures are discussed.