A new scattering mechanism of acoustic phonons in relaxor ferroelectrics: the case of KTa_{1-x}Nb_xO_3

J. Toulouse; E. Iolin; B. Hennion; D. Petitgrand; G. Yong; R. Erwin

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arXiv · 1001.4096

A new scattering mechanism of acoustic phonons in relaxor ferroelectrics: the case of KTa_{1-x}Nb_xO_3

J. Toulouse·E. Iolin·B. Hennion·D. Petitgrand·G. Yong·R. Erwin

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Abstract

The complex interaction between transverse acoustic (TA) phonon, transverse optic (TO) phonon and polar nano-domains (PND) in the relaxor ferroelectric KTa1-xNbxO3 (KTN) is studied by means of high resolution diffuse and inelastic neutron scattering. The experimental results and a comparison with lead relaxors, suggest a new scattering mechanism of the TA phonon by localized modes in PNDs. A theoretical model is developed, which accurately predicts the evolution of the TA damping with temperature and wavevector. Such a mechanism suggests the possible use of high frequency acoustic modes for the study of nanocomposite materials.

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J. Toulouse, E. Iolin, B. Hennion, D. Petitgrand, G. Yong, R. Erwin. 2010-01-22. A new scattering mechanism of acoustic phonons in relaxor ferroelectrics: the case of KTa_{1-x}Nb_xO_3. https://arxiv.org/abs/1001.4096

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