Experimental Evidence for Non-Collinear Antiferro-toroidic Ground State in a Dy₈ Molecule

The single molecular toroics are a class of coordination complexes that exhibit spin vortex chiral ground states due to non-collinear arrangements of local magnetic moments. While ab initio methods can predict local magnetic moments, unequivocal experimental determination has proven more challenging. Typically, angular dependent single crystal magnetization would be a good method to obtain anisotropy information. However, periodicity resultant from the cluster symmetry has hindered the use of this method for the study of many complexes including Dy₃ [1]. In this work, we consider a snub square molecule, Dy₈ [2]. Multiple orientation single crystal magnetization, measured at 0.3 K, reveal the orientation of moments. These measurements, with a simple Ising model, are used to identify a zero toroidal ground state in Dy8, highlighting the robustness of vortex chirality within larger Dy based molecular lattices.
1. J. Luzon, K. Bernot, I.J. Hewitt, C. E. Anson, A.K. Powell and R. Sessoli, Phys Rev Lett. 2008, 100, 247205.
2. D. I. Alexandropoulos, A. Fournet, L Cunha-Silva, A. M. Mowson, V. Bekiari, G. Christou and T. C. Stamatatos, 2014, Inorg. Chem. 53, 5420.