Gadolinium as a single atom catalyst in a single molecule magnet

TL;DR

This study demonstrates that gadolinium acts as a single atom catalyst in a single molecule magnet, influencing magnetic stability and relaxation dynamics in endohedral fullerenes, with implications for magnetic nanomaterials.

Contribution

It reveals Gd's role as a catalyst that accelerates magnetic relaxation and alters energy barriers in endohedral fullerenes, a novel insight into magnetic behavior at the atomic level.

Findings

Gd decreases magnetization stability in Dy2ScN@C80.

Gd's magnetic moment follows external and Dy dipolar fields.

Lower exchange barrier observed with Gd substitution.

Abstract

Endohedral fullerenes are perfect nanolaboratories for the study of magnetism. The substitution of a diamagnetic scandium atom in Dy2ScN@C80 with gadolinium decreases the stability of a given magnetization and demonstrates Gd to act as a single atom catalyst that accelerates the reaching of thermal equilibrium. X-ray magnetic circular dichroism at the M4,5 edges of Gd and Dy shows that the Gd magnetic moment follows the sum of the external and the dipolar magnetic field of the two Dy ions and compared to Dy2ScN@C80 a lower exchange barrier is found between the ferromagnetic and the antiferromagnetic Dy configuration. The Arrhenius equilibration barrier as obtained from superconducting quantum interference device magnetometry is more than one order of magnitude larger, though a much smaller prefactor imposes faster equilibration in Dy2GdN@C80. This sheds light on the importance of the angular momentum balance in magnetic relaxation.