Photoluminescence investigations on the nanoscale phase transition in Pb(Mg_(1/3)Nb_(2/3))O_3

摘要

The temperature dependence of the photoluminescence spectra of the relaxor ferroelectric Pb(Mg_(1/3)Nb_(2/3))O_3 has been reported. The temperature behaviours of the 1.57, 1.67 and 1.73 eV bands indicate a phase transition at 110 K. This is attributed to a structural phase transition in the charged nanoshell. Analysis of the temperature dependence of 1.67 eV band intensity with a thermal quenching model indicated the existence of a phonon mode at 1153 cm~(-1). This mode is identified in the Raman spectra measurement. The intensity of the 1.73 eV band showing an anomalous behaviour at 210 K is attributed to a transition from a crystalline phase to an amorphous phase in the charged nanoshell.