Ferroelectric ordering in the relaxor Pb(Mg1/3Nb2/3)O3 as evidenced by low-temperature phonon anomalies

By S. Wakimoto, C. Stock, R. Birgeneau, Zuo-Guang Ye, W. Chen, W. Buyers, P. Gehring, G. Shirane. 2001

138 citations recorded by the source corpus.

Neutron scattering measurements of the lowest-energy TO phonons in the relaxor Pb(Mg 1 / 3 Nb 2 / 3 )O 3 (PMN) are reported for 10≤T7≤50 K. The soft mode, which is overdamped by the polar nanoregions below the Burns temperature T d =620 K, surprisingly recovers below 220 K. The square of the soft-mode energy (∞ω 0 ) 2 increases linearly with decreasing temperature and is consistent with the behavior of a ferroelectric soft mode. At 10 K, ∞ω 0 reaches II meV, the same value observed in ferroelectric Pb(Zn 1 / 3 Nb 2 / 3 )O 3 at low T. An unusual broadening of the TA phonon starts at T d and disappears at 220 K, coincident with the recovery of the TO mode. These dynamics suggest that a well-developed ferroelectric state is established below 220 K.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/894f89eda7d611bf4cdd32b1073e20d41df0fedd