Perfect Spin Filtering in Homobimetallic Ni Complex with High Tolerance to Structural Changes.

Abstract

In the theory of ligand field, depending on the nature and field strength of the surrounding ligands, the central metal ion may exhibit different electronic configurations, low spin(LS) and high spin(HS). Realizing stable spin polarization is one of the main challenges in molecular spintronic devices field due to spin switching triggered by external stimulus. Here, an asymmetric homobimetallic complex has been investigated using the non-equilibrium Green s function and spin density functional theory. Our calculations indicate that the homobimetallic complex can achieve negative differential resistance, rectification effect and perfect spin filtering transport on the level of individual molecule. Strikingly, when the molecule is stretched by 0.45 Å, the HS state is still the most stable due to the weak magnetic Ni-Ni interaction. Despite its conductivity decreases by 30%, the efficiency of spin filtering remains 100%. These obtained theoretical findings suggest that the homobimetallic complexes hold great potential in molecular spintronics.