[en] We investigate the interplay of magnetization and lattice vibrations in rare-earth orthoferrites RFeO3, with a specific focus on non-symmetry-breaking anomalies. To do so, we study the magnetization, magnon excitations and lattice dynamics as a function of temperature in NdFeO3, TbFeO3, EuFeO3 and GdFeO3. The magnetization shows distinct temperature anomalous behavior for all investigated rare-earth orthoferrites, even in the compounds with no phase transitions occurring at those temperatures. Through spin-phonon coupling, these magnetic changes are mirrored by the FeO6 rotation mode for all the studied RFeO3, revealing a common magnetostructural effect associated with the octahedra rotations. The R3+ oscillation modes evidence a Fe3+/R3+ spins cross-talk for the NdFeO3 and TbFeO3 cases. Our work sheds light into the common magnetostructural coupling in rare-earth orthoferrites, and the important role of magnetic anisotropy and spin-orbit coupling strength of the R-Fe interactions on the spin-reorientation transition at high temperatures.
We are deeply acknowledged to J. L. Ribeiro for the fruitful discussion regarding the interpretation of the magnetic data, and P. Bouvier suggestions on the analysis of some specific phonons. We acknowledge funding from NORTE-01-0145-FEDER-022096, UID/NAN/50024/2019 and PTDC/NAN-MAT/28538/2017 projects and R.V. to the grant from PTDC/NAN-MAT/0098/2020.
[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS)]
