Electronic and vibrational Raman spectroscopy of Nd₀.₅Sr₀.₅MnO₃ through the phase transitions

Original · EN

Raman scattering experiments have been carried out on single crystals of Nd₀.₅Sr₀.₅MnO₃ as a function of temperature in the range of 320-50 K, covering the paramagnetic insulator-ferromagnetc metal transition at 250 K and the charge-ordering antiferromagnetic transition at 150 K. The diffusive electronic Raman scattering response is seen in the paramagnetic phase which continue to exist even in the ferromagnetic phase, eventually disappearing below 150 K. We understand the existence of diffusive response in the ferromagnetic phase to the coexistence of the different electronic phases. The frequency and linewidth of the phonons across the transitions show significant changes, which cannot be accounted for only by anharmonic interactions.