Indirect magnetic interaction mediated by spin dimer in Cu$_2$Fe$_2$Ge$_4$O$_{13}$

TL;DR

This study investigates how Cu dimers mediate indirect magnetic interactions between Fe ions in Cu$_2$Fe$_2$Ge$_4$O$_{13}$ using inelastic neutron scattering, revealing their role as nonmagnetic media facilitating superexchange.

Contribution

It provides experimental evidence of indirect Fe-Fe exchange coupling mediated by Cu dimers, with parameters consistent with semi-static estimates, highlighting the mediating role of Cu dimers.

Findings

Observed indirect Fe-Fe exchange coupling via Cu dimers.

Quantified effective interaction parameters consistent with theoretical estimates.

Confirmed Cu dimers act as nonmagnetic media in magnetic interactions.

Abstract

Cu$_2$Fe$_2$Ge$_4$O$_{13}$ is a bicomponent compound that consists of Cu dimers and Fe chains with separate energy scale. By inelastic neutron scattering technique with high-energy resolution we observed the indirect Fe - Fe exchange coupling by way of the Cu dimers. The obtained parameters of the effective indirect interaction and related superexchange interactions are consistent with those estimated semi-statically. The consistency reveals that the Cu dimers play the role of nonmagnetic media in the indirect magnetic interaction.