Exploring the transport properties of equatorially low coordinated erbium single ion magnets

TL;DR

This study investigates the transport properties of three erbium-based single ion magnets, revealing their potential for spin filtering in spintronic devices through theoretical simulations and ligand field analysis.

Contribution

The paper provides a theoretical screening of three low-coordinated erbium single ion magnets, demonstrating their potential for spin filtering and retention of magnetic properties in device-like environments.

Findings

Molecules retain single-molecule magnet behavior in device setup.

Simulations suggest remarkable spin filtering under magnetic field.

Ligand field analysis confirms ground state characteristics.

Abstract

Single-molecule spin transport represents the lower limit of miniaturization of spintronic devices. These experiments, although extremely challenging, are key to understand the magneto-electronic properties of a molecule in a junction. In this context, theoretical screening of new magnetic molecules provides invaluable knowledge before carrying out sophisticated experiments. Herein, we investigate the transport properties of three equatorially low-coordinated erbium single ion magnets with $C_{3v}$ symmetry: Er[N(SiMe$_3$)$_2$]$_3$ (1), Er(btmsm)$_3$ (2) and Er(dbpc)$_3$ (3), where btmsm = bis(trimethylsilyl)methyl and dbpc = 2,6-di-tert-butyl-p-cresolate. Our ligand field analysis, based on previous spectroscopic data, confirms a ground state mainly characterized by $M_J$ =$\pm$15/2 in all three of them. The relaxation of their molecular structures when placed between two Au (111) electrodes leads to an even more symmetric $\sim D_{3h}$ environment, which ensures that these molecules would retain their single-molecule magnet behavior in the device setup. Hence, we simulate spin dependent transport using the DFT optimized structures on the basis of the non-equilibrium Green's function formalism, which, in 1 and 2, suggests a remarkable molecular spin filtering under the effect of an external magnetic field.