The interplay of strong single-ion anisotropy and magnetic interactions often give rise to novel magnetic behavior and can provide additional routes for controlling magnetization dynamics. However, novel effects arising from interactions between lanthanide and transition-metal ions are nowadays rarely observed. Herein, a {DyIIICu5II} 3d-4f single-molecule magnet (SMM) is constructed as a rigid and planar [15-MC-5] metallacrown (MC), where the DyIII ion is trapped in the central pseudo-D5h pocket. A strong axial crystal field (CF) imbues the DyIII ion with large Ising-type magnetic anisotropy, and we are able to observe and model the magnetic interactions between the CuII−CuII and DyIII−CuII pairs. Butterfly-shaped magnetic hysteresis shows clear steps at ±0.4 T, coincident with level crossings in our model exchange Hamiltonian between the {Cu5II} and DyIII spin systems. Most intriguingly, this air-stable SMM exhibits three distinct regimes in its magnetic relaxation dynamics, all clearly displaying an exponential dependence on temperature.
@article{arxiv.1804.05818,
title = {Triple Exponential Relaxation Dynamics in a Metallacrown-Based {$Dy^{III}Cu^{II}_5$} 3d-4f Single-Molecule Magnet},
author = {Quan-Wen Li and Rui-Chen Wan and Jin Wang and Yan-Cong Chen and Jun-Liang Liu and Daniel Reta and Nicholas F. Chilton and Zhen-Xing Wang and Ming-Liang Tong},
journal= {arXiv preprint arXiv:1804.05818},
year = {2018}
}