Strong magnetoelastic coupling in orthorhombic Eu1-xYxMnO3 manganite

This work reports an experimental study on the temperature dependence of the structural parameters in orthorhombic Eu1-xYxMnO3 system at low temperatures, by using synchrotron x-ray diffraction technique. A significant magnetoelastic coupling is revealed by anomalies observed in lattice parameters at the magnetic phase transitions, apparent also in both Mn-O bond lengths and Mn-O1-Mn bond angle. Furthermore, signatures of the lattice deformations across the magnetic phase transitions were evidenced by anomalies in the temperature dependence of the lattice mode involving rotations of the MnO6 octahedra. These anomalies confirm the important role of the spin-phonon coupling in these materials.