Probing Magnetic Excitations and possibility of magnon-phonon in NdMnRuO5 through Inelastic Neutron Scattering

The exploration of magnetoelectric (ME) coupling and multiferroicity in complex oxides has attracted considerable attention due to their potential in multifunctional device applications. We have synthesized and investigated a new system, NdMnRuO5, which is closely derived from well-known multiferroic RMn2O5 and offers a unique platform to investigate the interplay between spin, lattice, and orbital degrees of freedom. Bulk magnetization and dielectric measurements on this compound reveal multiple magnetic transitions near 60 K, 40 K, and 15 K suggesting the presence of competing interactions, spin reorientation, and possible magnetic frustration. XPress inelastic neutron scattering (INS) measurement performed on MARI instrument indicate the existence of low-energy excitations around 7.6 and 15.2 meV, which persist at high momentum transfers, implying potential magnon-phonon coupling. To elucidate the microscopic origin of these excitations, we propose detailed temperature-dependent INS measurements. The study aims to map spin-wave spectra, crystal-field excitations of Nd3+, and their coupling with lattice vibrations to understand how 4f-3d/4d exchange interactions and lattice distortions govern low-energy ME coupling. This work will provide direct experimental insights into the dynamic magnetoelectric behavior of NdMnRuO5 and helps to understand the spin-lattice hybridization in multiferroic oxides.