Local characterization of nanostructured high sensitivity piezoelectric BiScO₃-PbTiO₃ ceramics by piezoresponse force microscopy

Piezoresponse force microscopy has been used for the local characterization of high sensitivity piezoelectric BiScO₃-PbTiO₃ ceramics with compositions close to the morphotropic phase boundary, with decreasing grain sizes down to 28 nm. The use of this high resolution technique has allowed not only the analysis of the evolution of the ferroelectric domain configurations, with the disappearance of ferroelastic domains at the nanoscale, but also to establish the existence of correlations among the polarization of adjacent single-domain grains and the formation of inversion superdomains. The effect of the grain size reduction on the piezoelectric coefficients was also studied. Finally, piezoelectric loops have been obtained on the smallest grains, and some distinctive features, such as an atypical clockwise hysteresis is discussed and related to high resistivity grain boundaries.