Optical studies of ferroelectric phase transition in deuterated triglycine sulfate crystals

Abstract

We report on precise experimental measurements with the Senarmont technique of optical birefringence in partly deuterated triglycine sulfate crystals (DTGS, deuteration degree x ≈ 0.7) and interpretation of the influence of ferroelectric phase transition (PT) on the birefringence. The critical phenomena observed, not too close to the PT point, are quantitatively analysed. The fluctuation effects are shown to be fairly well described in terms of the approach of first fluctuation correction to the Landau theory. We have derived spontaneous electrooptic characteristics of DTGS and revealed that deuteration improves those characteristics.

Keywords:

• Ferroelectric crystals
• Phase transitions
• Critical phenomena
• Fluctuations
• Deuterated triglycine sulfate
• Optical birefringence

Acknowledgements

The authors are grateful to Prof. L.A. Shuvalov and Dr A.I. Otko for DTGS crystals and Prof. Y.I. Shopa for valuable discussions.

Notes

†The authors were pointed to this feature in the discussion during the VIII Ukrainian-Polish and III East-European Meeting on Ferroelectrics Physics (Lviv, Ukraine, September 4–7, 2006).