Spin polarization and magnetic characteristics at C6H6/Co2MnSi(001) spinterface.

Abstract

Organic materials with mechanical flexibility, low cost, chemical engineering, and long spin lifetime attract considerable attention for building spintronic devices. Here, a C6H6/Co2MnSi(001) spinterface is investigated by first-principles calculations and spin-polarized scanning tunneling microscopy simulations. Several high symmetry adsorption sites are discussed, together with two possible surface terminations of Co2MnSi(001). An inversion of the spin polarization is induced near EF even in the case of an external electric field, indicating that C6H6 can act as a spin filter to exploit the spin injection efficiency in organic spintronic devices. Unlike previous studies on molecule/ferromagnet interfaces, this inversion is closely related to the electronic structure of the atoms in the subsurface layer of Co2MnSi according to the orbital symmetry analysis. Furthermore, the magnetic moment and magnetic anisotropic energy (MAE) in the outermost Co2MnSi layer are studied. Particularly, in the most stable configuration, the sign of MAE is inversed due to hybridization between C p and Co dz2 orbitals, which suggests that a greater modification on MAE can be achieved by the use of a highly chemically reactive organic molecule. These findings improve the study on the engineering of magnetic properties at molecule/ferromagnetic interfaces through a single π-conjugated organic molecule.