2. POLAR CLUSTERS IN: PLZT PSN-PMN-PZN SBN Mesoporous molecular sieves Conclusions

3. Ferroelectric memory Applied Physics Letters, 81, 4401 (2002). Domain size about 30 nm Net 1,5 Tbit/inch 2 ≈ 210 GB (300 CD) inch 2 (2,54x2,54 cm).

4. PLZT: Pb(1-x)La(x)Zr(y)Ti(1-y)O3 APPLICATIONS: Transducers Electro-optic devices Actuators FRAM

5. Polar nanoclusters ~ 10 nm Local ctructure – doubled unit cell Tilting oxygen octahedra THE AIM: Dynamics of polar nanoclusters Contribution to permittivity

6. Frequency ranges

7. 1 MHz to 3 GHz AGILENT 8714ET COAXIAL SPECTROMETER

8. The waveguide spectrometer 8 GHz to 120 GHz

9. 100 GHz to 3 THz Teraherthz spectroscopy

10. PLZT 8/65/35

11. Relaxation

12. ε * (  )    + .∫g(  )[d(logτ) /(1+i  )]

13. PMN- PSN- PZN ceramics PbMg(x)Nb(1-x)O3-PbSc(1/2)Nb(1/2)O3-PbZn(y)Nb(1-y)O3

14. PMN-PSN-PZN

15. Distribution of the relaxation times of PSN-PMN-PZN

16. a)b)c) SBN Sr 0,61-x Ba 0,39 Nb 2 O 6 : Co 3 O 4 (0,002%)

17. SBN

18. Distribution of the relaxation times of unpoled SBN

19. Comparison of distribution of the relaxation times of poled and not poled SBN

20. MCM – 41 Pore size 3.7 nm MOLECULAR SIEVE MATERIALS

21. The imaginary part of dielectric permittivity of MCM - 41 r

22. Confined polar materials dynamics

23. C O N C L U S I O N S  Dynamics of polar nanoclusters take place at radio and microwave frequencies.  Flipping of the polar nanoclusters causes high permittivity and lossess and microwave dielectric dispersion.  Dielectric spectroscopy allows to determine important macroscopic and microscopic parameters of polar ceramics, i.e. energy losses, parameters of polar nanoclusters, the distribution of relaxation times, etc.  In mesoporous materials three dielectric dispersion regions of the confined water in 3.7 nm pores have been found.  The relaxation time distribution shows reorientation of the water molecular dipole moments in a double well potential.

24. Co-workers: CO – WORKERS Prof. Juras Banys Assoc.prof. Algirdas Brilingas PhD students: Jan Macutkevic Robertas Grigalaitis Martynas Kinka In collaboration with: University of Latvia, Inst. of Physics, Czech Republik Leipzig University, Germany, etc.

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