The magnetic properties of the iron phthalocyanine molecule grafted to the Ti$_2$C MXene layer

TL;DR

This study uses density functional theory to analyze the magnetic interactions in a hybrid system of iron phthalocyanine molecules on Ti2C MXene, revealing ferromagnetic coupling and the influence of molecular states for potential spintronic applications.

Contribution

It provides new insights into the magnetic interactions and configurations of FePc on Ti2C MXene, highlighting the role of the ligand and substrate in controlling magnetic properties.

Findings

Ferromagnetic interaction between Fe and Ti layers.

Reorientation of Fe magnetic moment due to substrate interaction.

Analysis of different molecular and atomic configurations.

Abstract

The magnetic tetrapyrrole molecules (such as porphyrins and phthalocyanines) with an active transition metal atom in their centre are currently intensively studied as prosperous potential elements of devices for high-density information storage and processing. It has been recently proved that by means of external factors one could induce two stable fully controllable molecular states. Therefore, hybrid systems consisting of such magnetic molecules and suitable carriers from the family of two-dimensional materials are often considered as promising highly scalable spintronic systems that could in the near future lead to novel industrial applications. Here, we perform the spin polarised density functional theory (DFT) studies of the hybrid system, which is the iron phthalocyanine molecule (FePc) on the top of the titanium carbide Ti$_2$C MXene layer. The most relevant issue in this part is the interaction between magnetic atoms: Ti from MXene substrate and iron from FePc. Four various magnetic configurations of FePc/Ti$_2$C were considered. The significant ferromagnetic interaction between the iron atom and the upper titanium layer plays important role in the reorientation of the iron atom's magnetic moment. We also analyse a model of the system in which the FePc molecule is in a quintet state (the ground state of an isolated molecule is a triplet). To get a better understanding of the physics of the FePc/Ti$_2$C hybrid system, we studied the hybrid systems with a single iron atom and non-magnetic H$_2$Pc on the Ti$_2$C layer, Fe/Ti$_2$C and H$_2$Pc/Ti$_2$C, respectively, which nicely explains the role of the Pc ligand in the FePc/Ti$_2$C hybrid system.