Domain structure of lead germanate

Abstract

With the help of selective etchants as-grown domain structure arising as a result of the phase transition and its restruction in electric field is investigated in lead germanate single crystals. It is shown that this structure consists of small counter domains which are enlarged in electric field. By the use of stroboscopic lighting the domain dynamics under applied electric field is studied. It is shown that the influence of growth layers upon forward domain growth can be explained by the relative variation of the spontaneous polarization in the layers of the order of 0,1%. The observed peculiarities of sidewise motion of plane domain wall are explained by the presence of dielectric gap and by the influence of bulk screening. It is supposed that in low-field region domain wall motion occurs through the one-dimensional nucleation at the wall. Within this model it is possible to qualitatively explain the domain shape dependence on the switching conditions.