Jahn-Teller phonon anomaly and dynamic phase fluctuations in La0.7Ca0.3MnO3

Phys Rev Lett. 2001 Apr 23;86(17):3823-6. doi: 10.1103/PhysRevLett.86.3823.

Abstract

Inelastic neutron scattering was used to study the temperature (T) dependence of the lattice excitations in La 0.7Ca 0.3MnO (3). An optical Jahn-Teller phonon exhibits continuous but anomalous damping with increasing temperature in the ferromagnetic-metallic phase and collapses above the Curie temperature T(C) (240 K). We attribute this anomaly to the growing dynamic phase segregation as T-->T(C), thus providing evidence of local fluctuations associated with the short-range polaron or charge/orbital ordering in the ferromagnetic-metallic state.