PHONON-SCATTERING FROM FERROELECTRIC DOMAIN-WALLS - PHONON IMAGING INKDP

The ferroelectric domain wall is an ideal interface for studies of the boundary scattering of high frequency acoustic phonons. These interna l interfaces have no contamination and can be reversibly created and d estroyed by application of an electric field at the phase transition- 122 K in KDP. Images of phonons in single- and multiple-domain cases s how remarkable differences in the ballistic heat flux. Theoretical mod eling based on acoustic wave reflection reveals that the domain walls act as nearly perfect grain boundaries.