Determination of exchange energies in the sawtooth spin ring {Mo75V20} by ESR

TL;DR

This study uses ESR measurements to accurately determine exchange energies in the {Mo75V20} sawtooth spin ring, clarifying its magnetic properties and low-lying spectrum amidst impurity effects.

Contribution

It introduces ESR as an effective method to distinguish impurity effects and determine exchange parameters in complex molecular magnets.

Findings

Successfully determined exchange energies in {Mo75V20}

Discriminated impurity contributions from molecular magnetism

Provided insights into low-lying singlet states

Abstract

The magnetism of the polyoxometalate cluster {Mo75V20}, containing a sawtooth ring of 10 corner-sharing triangles located on the equator of the barrel-shaped molecule, has remained debatable since it is masked by contributions from impurities as well as temperature-independent paramagnetism. In this article we demonstrate the usefulness of ESR measurements since the temperature dependence of the ESR intensity can discriminate between impurity and molecular contributions. We determine the exchange parameters and therefore also the low-lying spectrum of {Mo75V20}, especially the low-lying singlet states which so far have been probed solely by specific heat measurements.