OBSERVATION OF FERROELECTRIC DOMAIN-STRUCTURES BY SECONDARY-ELECTRON MICROSCOPY IN AS-GROWN KTIOPO4 CRYSTALS

Ferroelectric domain structures of as-grown KTiOPO4 crystals are obser ved on polished polar surfaces by the scanning secondary-electron micr oscopy (SEM) method. The results demonstrate a different contrast orig in for domain boundaries and domains themselves. It is shown that the electron-beam irradiation in SEM causes a local heating of the ferroel ectric crystal. Detailed calculations of the effects involved allow to assume that pyroelectric potentials induced by heating are opposite i n sign for C+ and C- domains which is the main reason for the domain c ontrast. Domain boundaries are revealed due to the converse piezoelect ric effect and the corresponding crystal deformations of ferroelectric domains are induced by electron-beam charging.