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Disorder and relaxation mode in the lattice dynamics of PbMg$_{1/3}$Nb$_{2/3}$O$_3$ relaxor ferroelectric

S. N. Gvasaliya·S. G. Lushnikov·B. Roessli
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Abstract

The low-energy part of vibration spectrum in PbMg$_{1/3}$Nb$_{2/3}$O$_3$ relaxor ferroelectric was studied by inelastic neutron scattering. We observed the coexistence of a resolution-limited central peak with strong quasielastic scattering. The line-width of the quasielastic component follows a $Γ_0+Dq^2$ dependence. We find that $Γ_0$ is temperature-dependent. The relaxation time follows the Arrhenius law well. The presence of a relaxation mode associated with quasi-elastic scattering in PMN indicates that order-disorder behaviour plays an important rôle in the dynamics of diffuse phase transitions.

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S. N. Gvasaliya, S. G. Lushnikov, B. Roessli. 2003-11-05. Disorder and relaxation mode in the lattice dynamics of PbMg$_{1/3}$Nb$_{2/3}$O$_3$ relaxor ferroelectric. https://doi.org/10.1103/physrevb.69.092105

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