Indentation induced local polarization reversal in La doped BiFeO3 ceramics

Stress-induced local polarization reversal was studied in La doped BiFeO3 ceramics under the action of Berkovich-type prism indentation. Piezoresponse force microscopy was used for detailed study of domain structure before and after local polarization reversal. Two mechanisms of domain formation under the action of the mechanical loading were revealed: (1) direct stress-induced and (2) stress mediated by grain clamping. Critical stress value for local polarization reversal was extracted from the dependence of the switched area on the applied loading force.