Lattice and spin excitations have been studied by Raman scattering in hexagonal YbMnO 3 single crystals. The temperature dependences of the phonon modes show that the E 2 mode at 256 cm -1 related to the displacement of Mn and O ions in a-b plane is coupled to the spin order. The A 1 phonon mode at 678 cm -1 presents a soft mode behavior at the Néel temperature. Connected to the motion of the apical oxygen ions along the c direction, this mode controls directly the Mn-Mn interactions between adjacent Mn planes and the superexchange path. Crystal field and magnon mode excitations have been identified. The temperature investigation of the spin excitations shows that the spin structure is strongly influenced by the Yb-Mn interaction. Under a magnetic field along the c axis, we have investigated the magnetic reordering and its impact on the spin excitations.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Nov 9 2012|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics