Birefringence of mechanically clamped TGS crystals with L‑valine admixture

 

Chem. Met. Alloys 4 (2011) 46-49

 

Vasyl STADNYK, Mykola ROMANYUK, Yurij KIRYK, Ruslan BREZVIN

 

The influence of uniaxial mechanical stresses applied along the crystal-physical axes on the principal values of the birefringence, Dni, was studied for TGS crystals with 5% L-valine admixture. It was found that Dni are quite sensitive to stress and adopt different values and opposite signs, when compared to pure TGS. The baric coefficients c/m for the phase transition (PT) temperature appear to be less than for pure TGS. The temperature dependence of the combined piezooptic constants was calculated. The values of the jump-like changes occurring for all the piezooptic constants at the PT are notably lower for the doped crystals than for pure TGS.

 

Temperature dependence of the piezooptic constants of TGS crystals doped with 5% L‑valine, measured at λ = 500 nm

 

Keywords

Birefringence / Uniaxial pressure / Phase transitions / Piezooptic constants