Tunable magnetism in 2D organic-ion-intercalated MnPS3 via molecule-dependent vacancy generation

TL;DR

This study demonstrates that intercalating specific molecules into MnPS3 flakes can controllably induce and tune various magnetic states, including ferrimagnetism, enabling localized magnetic heterostructures within a single 2D material.

Contribution

It introduces a method to tailor magnetic properties of MnPS3 via molecule-dependent vacancy generation, including partial intercalation for localized magnetic heterostructures.

Findings

Intercalation of alkylammonium ions creates Mn2+ vacancies.

Vacancy generation induces a transition from antiferromagnetic to ferrimagnetic states.

Partial intercalation enables the formation of magnetic heterostructures within a single flake.

Abstract

The magnetic properties of van der Waals materials are profoundly influenced by structural defects. The layered antiferromagnet MnPS3 offers a unique opportunity to explore defect-related magnetism, as Mn2+ vacancies can be generated by the intercalation of specific guest molecules. However, the effectiveness of this process in atomically thin flakes and the extent of the magnetic tunability remain unclear. Here, we show that the magnetic properties of MnPS3 can be tailored through the intercalation of different guest molecules. Notably, the insertion of four alkylammonium ions introduces different populations of Mn2+ vacancies, leading to a transition from the pristine antiferromagnetic state to more complex magnetic textures, including a ferrimagnetic state displaying a magnetic saturation of 1 uB/atom. Moreover, we show that the intercalation of few-nm-thick flakes also leads to the emergence of a ferrimagnetic response. This in-flake intercalation, which can be monitored in real time using optical microscopy, can be interrupted before completion, generating lateral heterostructures between pristine and intercalated areas. This approach opens the way to the use of partial intercalation to define regions with distinct magnetic properties within a single flake.