Thermal expansion and memory effect in the ferroelectric-semiconductor TlGaSe2.

The effect of thermal annealing within the incommensurate phase (memory effect) on thermal expansion of ferroelectric-semiconductor crystal TlGaSe₂ has been investigated. Strong transformation of linear expansion coefficients both in the layers plane and in the direction perpendicular to the layers has been observed for the first time as a result of annealing. It is supposed that internal electric fields (electret states) activated during the annealing greatly effect the dimension of the crystal via electrostriction. [ABSTRACT FROM AUTHOR]