Stress induced movement of ferroelastic domain walls in BaTiO3 single crystals evaluated by scanning force microscopy

We report on the quantitative investigation of lateral domain wall motion i n BaTiO3 single crystals subjected to a compressive unidirectional mechanic al stress. Simultaneous to the mechanical testing, the single crystals prep ared by the modified exaggerated growth method were characterized by scanni ng force microscopy and piezoresponse force microscopy (PFM) which allow bo th topographical details and the true three-dimensional ferroelectric domai n configuration to be reproduced simultaneously. Stress induced domain form ation is initiated at the sample surface followed by the forward- and later al-domain growth both perpendicular and parallel to the direction of induce d stress. Knowing the crystallographic orientation of the BaTiO3 single cry stal (from Kikuchi patterns) clearly associates our experimental observatio ns with a 90 degrees domain switching process, in accordance with a theoret ical model. Additionally. 180 degrees ferroelectric domain boundaries (a-do mains) were detected with PFM which are not visible from the sample topogra phy. The formation of these newly formed domains is driven by the compensat ion of the positive surface charge arising from the ferroelastic growth of C+ domains. (C) 2001 Published by Elsevier Science B.V.