Skip to Main content Skip to Navigation
Journal articles

Influence of defects and domain walls on dielectric and mechanical resonances in LiNbO$_3$

Abstract : Monodomain and periodically poled LiNbO$_3$ crystals (congruent composition) show dielectric and piezoelectric resonances between 100 K and 900 K. Dielectric measurements show resonances in some samples between 10–100 kHz. These resonances vanish under thermal anneal in monodomain crystals while they remain stable in periodically poled samples with high domain wall densities. The low activation energy of 0.18 eV suggests their electronic (bi-polaronic) origin. Resonant piezoelectric spectroscopy, RPS, shows two features in virgin samples: a relaxation peak at 420 K and a rapid hardening when the sample was slowly heated to ~500 K. The dynamic relaxation and the hardening are related to excitations and reorientations of Li defects. The relaxations and hardening are irreversibly suppressed by high temperature anneal. We do not observe domain wall related RPS resonances in annealed samples, which excludes the existence of highly charged walls. We suggest that domain walls stabilize polaronic states with (bi-)polarons located inside or near to the ferroelectric domain walls.
Document type :
Journal articles
Complete list of metadata
Contributor : Dominique GIRARD Connect in order to contact the contributor
Submitted on : Thursday, June 29, 2017 - 5:32:28 PM
Last modification on : Monday, December 13, 2021 - 9:14:57 AM


Publisher files allowed on an open archive



Guillaume F Nataf, Oktay Aktas, Torsten Granzow, Ekhard K. H. Salje. Influence of defects and domain walls on dielectric and mechanical resonances in LiNbO$_3$. Journal of Physics: Condensed Matter, IOP Publishing, 2015, 28, pp.015901. ⟨10.1088/0953-8984/28/1/015901⟩. ⟨cea-01550765⟩



Record views


Files downloads