Magnon and electromagnon excitations in Dy0.9Nd0.1FeO3 single crystals tuned with temperature and magnetic field

Magnon and electromagnon excitations in RFeO3 (where R is a rare-earth element) are associated with the orderings of Fe and R ions, respectively, both of which strongly depend on temperature and applied magnetic field. Herein, by employing the magnetic and electric components of terahertz radiation, we have investigated the temperature and magnetic field dependent magnon and electromagnon excitations in Dy0.9Nd0.1FeO3 single crystals. Our results demonstrate that a small fraction of Nd-substituted Dy ion in Dy1−xNdxFeO3 (with x = 0.1) single crystals shows negligible influence on quasi-ferromagnetic (q-FM) and quasi-antiferromagnetic (q-AFM) modes when the temperature is above TNR, the ordering temperature of rare-earth ions. By contrast, introduction of 10% doping concentration of Nd element leads to changes in exchange interaction of rare-earth ions, consequently altering the frequencies of the electromagnon. Applying magnetic field along different crystal axes can tune the frequency of both q-FM and q-AFM modes and even trigger Fe3+-based spin reorientation phase transition. Furthermore, application of magnetic field can suppress the ordering of rare-earth ions and electromagnon excitation. We anticipate that our findings can advance the understanding of magnetoelectric coupling mechanisms and pave the way for the development of advanced multiferroic materials with tailored properties.