Spin-enhanced magnetocaloric effect in molecular nanomagnets

TL;DR

This paper reports a significant magnetocaloric effect in Fe14 molecular nanomagnets below 10 K, driven by large spin ground states and low-lying excited states, with implications for low-temperature magnetic cooling.

Contribution

It demonstrates the large magnetocaloric effect in Fe14 nanomagnets and links it to their high symmetry and spin properties, revealing new insights into molecular nanomagnet behavior.

Findings

Large magnetocaloric effect below 10 K in Fe14.

Long-range antiferromagnetic order below 1.87 K.

Correlation between symmetry, spin states, and magnetic properties.

Abstract

An unusually large magnetocaloric effect for the temperature region below 10 K is found for the Fe14 molecular nanomagnet. This is to large extent caused by its extremely large spin S ground-state combined with an excess of entropy arising from the presence of low-lying excited S states. We also show that the highly symmetric Fe14 cluster core, resulting in small cluster magnetic anisotropy, enables the occurrence of long-range antiferromagnetic order below T_N=1.87 K.