Interplay between static and dynamic polar correlations in relaxor Pb(Mg1/3Nb2/3)O-3

Date
2010-04-01Author
Stock, Chris
Van Eijck, L.
Fouquet, P.
Maccarini, M.
Gehring, Peter M.
Xu, Guangyong
Luo, Hongjie
Zhao, X.
Li, Jiefang
Viehland, Dwight D.
Metadata
Show full item recordAbstract
We have characterized the dynamics of the polar nanoregions in Pb(Mg1/3Nb2/3)O-3 through high-resolution neutron-backscattering and spin-echo measurements of the diffuse-scattering cross section. We find that the diffuse-scattering intensity consists of both static and dynamic components. The static component first appears at the Curie temperature Theta similar to 400 K while the dynamic component freezes completely at the temperature T-f similar to 200 K; together, these components account for all of the observed spectral weight contributing to the diffuse-scattering cross section. The integrated intensity of the dynamic component peaks near the temperature at which the frequency-dependent dielectric constant reaches a maximum (T-max) when measured at 1 GHz, i.e., on a time scale of similar to 1 ns. Our neutron-scattering results can thus be directly related to dielectric and infrared measurements of the polar nanoregions. Finally, the global temperature dependence of the diffuse scattering can be understood in terms of just two temperature scales, which is consistent with random-field models.