Spin-Transport Tuning of Individual Magnetic Mn-Salophen Molecule via Chemical Adsorption.

Feifei Li,Jing Huang,Qunxiang Li,Jianing Wang

doi:10.3390/molecules24091747

Abstract

Control over spin states at the single molecule level is a key issue in the emerging field of molecular spintronics. Here, we explore the chemical adsorption effect on the magnetic and spin-transport properties of individual magnetic molecule by performing extensive density functional theory calculations in combining with non-equilibrium Green’s function method. Theoretical results clearly reveal that the molecular magnetic moment of Mn-salophen can be effectively tuned by adsorbing F and CO on the central Mn cation, while the adsorbed NO molecule quenches the molecular magnetic moment. Without chemical adsorption, the currents through Mn-salophen molecular junction just show a little distinction for two spin channels, which agrees well with previous investigation. Remarkably, the conductive channel can be switched from the spin-up electrons to the spin-down electrons via adsorbing F and CO, respectively, and the corresponding two Mn-salophen molecular junctions with chemical modifications display nearly perfect spin-filtering effect. The observed spin switch and the predicted spin-filtering effect via chemical adsorption indicates that Mn-salophen holds potential applications in molecular spintronic devices.

Highlights

Molecular spintronic devices based on the magnetic molecule as the functional units, such as molecular rectifier, molecular switch, and molecular transistor, have already attracted a great deal of attention in recent years since it holds promise for the generation of electronic devices with enhanced functionality and improved performance [1,2,3,4,5,6,7]
It is well known that the electronic structure, magnetism and transport property of magnetic molecules can be effectively altered by varies external stimulus, such as electric field, strain, and carrier doping [8,9,10]
Green’s function method, we explore the spin states and spin-transport properties of Mn-salophen sandwiched between Au electrodes

Summary

Introduction

Molecular spintronic devices based on the magnetic molecule as the functional units, such as molecular rectifier, molecular switch, and molecular transistor, have already attracted a great deal of attention in recent years since it holds promise for the generation of electronic devices with enhanced functionality and improved performance [1,2,3,4,5,6,7]. Several experimental and theoretical investigations have demonstrated that an efficient method, via chemical adsorption using small molecules, such as CO, NO, NH3 , and O2 [11,12,13,14,15,16], to manipulate the spin states and tune their transport properties of magnetic molecules. Understanding the chemical adsorption effect is crucial to gain control over the spin states and spin-transport properties of a given magnetic molecules. We revisit Mn-salophen and try to explore the chemical adsorption effect on the magnetic and spin-transport properties of Mn-salophen sandwiched between two Au(100) electrodes by performing extensive density functional theory calculations combining with non-equilibrium Green’s function method. The observed nearly perfect spin-filtering effect and the switching between two spin channels implies that Mn-salophen is a promising candidate for designing molecular spintronic devices

Computational Parameters and Method

Results and Discussion

Conclusions