Perturbated regions in the vicinity of domain wall in ferroelastic-ferroelectric crystals

Abstract
Two different techniques are used to establish the strain distributions near the domain walls in ferroelastic-ferro-electric crystals (KDP, GMO, TAN ANE); classical optical techniques can give some results for domain structures not far from the monodomain state; γ-ray diffractometry is useful for dense domain structures (sample near zero macroscopic deformation).