Journal Article

Magnetic hysteresis up to 80 kelvin in a dysprosium metallocene single-molecule magnet

Mansikkamäki, Akseli, Day, Benjamin M., Tong, Ming-Liang, Chen, Yan-Cong, Guo, Fu-Sheng, Layfield, Richard A.

2018

Overview

Single-molecule magnets could prove useful in miniaturizing a wide variety of devices. However, their application has been severely hindered by the need to cool them to extremely low temperature using liquid helium. Guo et al. now report a dysprosium compound that manifests magnetic hysteresis at temperatures up to 80 kelvin. The principles applied to tuning the ligands in this complex could point the way toward future architectures with even higher temperature performance. Science , this issue p. 1400 Ligand tuning raises the upper temperature for hysteresis in a single-molecule magnet just above nitrogen’s boiling point. Single-molecule magnets (SMMs) containing only one metal center may represent the lower size limit for molecule-based magnetic information storage materials. Their current drawback is that all SMMs require liquid-helium cooling to show magnetic memory effects. We now report a chemical strategy to access the dysprosium metallocene cation [(Cp i Pr5 )Dy(Cp*)] + (Cp i Pr5 , penta-iso-propylcyclopentadienyl; Cp *, pentamethylcyclopentadienyl), which displays magnetic hysteresis above liquid-nitrogen temperatures. An effective energy barrier to reversal of the magnetization of U eff = 1541 wave number is also measured. The magnetic blocking temperature of T B = 80 kelvin for this cation overcomes an essential barrier toward the development of nanomagnet devices that function at practical temperatures.

• Publisher: The American Association for the Advancement of Science
• Subject: Cations / Climate / Cooling effects / Coordination compounds / Dysprosium / Dysprosium compounds / Helium / High temperature / Hysteresis / Information storage / Liquid helium / Low temperature / Magnets / Miniaturization / Nitrogen / Organic chemistry / Temperature / Temperature effects