Half-Metallicity of the Fe-Based Single Atomic Chains in CoFeTiAl Quaternary Semiconductor.

In this work, the Fe-based single atomic chains are designed in the semiconductive CoFeTiAl quaternary Heusler matrix by substituting Ti, Al, or Ti-Al with Fe in [001] crystallographic direction. We have investigated the electronic structures and magnetic characteristics of the Fe-based supercells by using the first-principles calculations. Our results show that all the three kinds of single atomic chains Fe-Al, Fe-Ti, and Fe-Fe atomic chains show a half-metallicity with 100 % spin polarization. A conductive nanopillar is formed and dilutedly distributed in CoFeTiAl matrix. The width of the nanopillar is about half of the lattice parameter, and the length of it will be adjustable. It would be an ideal method to design the new direct-current-magnetic memory device. [ABSTRACT FROM AUTHOR]