With rising interest in organic-based materials for spintronic and multiferroic applications, it is important to fully understand their electrical and magnetic properties and to identify correlations between their structural and physical attributes. Research led by ISIS, with collaboration from staff at Durham University, used muon spin spectroscopy to understand the anomaly seen in the magnetic susceptibility measurements of TEA(TCNQ)2 (triethylammonium bis-7,7,8,8-tetracyanoquinodimethane). This allowed them to carry out an in-depth study of the magnetic transition in the material.
Previous work showed coupling between the magnetic and electronic properties occurring alongside a magnetic transition at around 120 K. However, the magnetism and magnetic ground state were not well understood. This work, published in the Journal of Materials Chemistry C, took a closer look at the ambiguous magnetic behaviour of TEA(TCNQ)2, and provided evidence of long range magnetic order. The molecules were ordered in a three-dimensional manner, in such a way that their magnetic moments were pointing in opposite directions to their nearest neighbour (known as 'Ising-like').
Related publication: “A 3D antiferromagnetic ground state in a quasi-1D pi-stacked charge-transfer system", J. Mater. Chem. C, 2018, 6, 12468, DOI: 10.1039/c8tc03709d
Authors: Adam Berlie (ISIS), Ian Terry (Durham University) and Marek Szablewski (Durham University).