Order-disorder transition in the ferroelectric LiTaO3

KİRACI A., Yurtseven H.

FERROELECTRICS, cilt.551, sa.1, ss.235-244, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 551 Sayı: 1
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1080/00150193.2019.1671068
  • Dergi Adı: FERROELECTRICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.235-244
  • Anahtar Kelimeler: Damping constant, relaxation time, activation energy, order-disorder transition, LiTaO3, PHASE-TRANSITION, RAMAN, MODE, SCATTERING, BEHAVIOR
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The temperature dependences of the damping constant and the relaxation time are calculated by using the Raman frequencies of a* and the lowest A(1) (TO) phonons in the ferroelectric phase close to the ferroelectric-paraelectric transition in LiTaO3 (T-C = 963 K). Both calculations are performed by considering the frequency as an order parameter for the pseudospin-phonon (PS) and the energy fluctuation (EF) models using the observed data from the literature. Values of the activation energies of this crystal are also deduced by using both models in this crystal. Our results show that the PS and EF models can describe the observed behavior adequately for the order-disorder transition in LiTaO3.