Measurement of Electric-Field-Induced Displacements in (Pb, La)TiO3 Thin Films Using Scanning Probe Microscopy

Electric-field-induced displacements in sputter-deposited (Pb, La)TiO3 thin films were investigated. Dynamic displacement-voltage hysteresis loops were measured by scanning probe microscopy. A strain of 0.08 to 0.1% was observed using a bipolar driving field of 142 kV/cm. Using a phenomenological approach, the field-induced piezoelectric and electrostrictive displacements were estimated from measured polarization and field-dependent permittivity data. Qualitative agreement was observed between the measured and calculated displacements. The compositional dependence of thin films was analyzed from the ratio of piezoelectric and electrostrictive displacements.