Role of rare-earth ionic radii on the spin-phonon coupling in multiferroic ordered double perovskites

TL;DR

This study examines how the size of rare-earth ions affects spin-phonon interactions in double perovskites, revealing that ionic radius does not significantly influence the coupling strength.

Contribution

It provides new insights into the role of rare-earth ionic radii on spin-phonon coupling in RE2NiMnO6 perovskites using Raman spectroscopy.

Findings

Spin-phonon coupling magnitude is unaffected by ionic radius.

The phonon position deviation follows a power law.

Coupling strength is consistent across different rare-earth ions.

Abstract

In this paper we investigated the influence of the rare-earth ionic radii on the spin-phonon coupling in RE2NiMnO6 double perovskites by Raman spectroscopy. Spin-phonon in dense Nd2NiMnO6 and Gd2NiMnO6 ceramics were investigated by Raman spectroscopy at low temperatures. The magnitude of the coupling observed in comparison with other isostructural compounds shows that it is not influenced by the rare-earth ionic radius, as well as the deviation of the position of the stretching phonon in the ferromagnetic phase with relation to the anharmonic contributions follows a power law.