Remixing 2D magnets

One of the key attractions of metal-organic materials is their variety: organic molecules can be tweaked and refashioned almost indefinitely. We have recently reported a new ‘crinkly magnet’, nickel dichloride 2,1,3-benzothiadizole (btd), with an unusual “noncollinear” magnetic structure. In this paper we explore what happens when the sulfur atom in btd is swapped for an oxygen atom.

We use high pressure measurements to show that oxygen makes the metal-organic magnet slightly stiffer, but this stiffness changed more in some directions than others. We also find that oxygen makes the magnet “softer” - that is the magnetic domains become significantly easier to switch. This paper is one of the first demonstrations that the modular, lego-like nature of MOFs can also be used to fine-tune their magnetic and mechanical properties.

This work was a collaboration with the Technical University of Munich and the Diamond Light Source (high pressure studies), and the national electron diffraction facility at the University of Warwick. Emily Myatt, the first author, carried out this work as a masters student in the group.