Ferroelectric analysis of Barium Titanate using Piezoresponse Force Microscopy
Ferroelectric materials are capable of maintaining a state of polarity in the absence of an electric field. They are also susceptible to the piezoelectric effect, where inducing mechanical stress will cause charges to accumulate within the material, and vice versa. Piezoresponse Force Microscopy was used to analyze the ferroelectric properties of Barium Titanate by measuring its topography and imparting a polarization by the application of an electric field. Multiple bitmap images were loaded into an Atomic Force Microscope to be written on the Barium Titanate sample with a bias of -8 to 8 Volts, then scanned in order to read the image which was imprinted into the charge density of the material. A consistent drive frequency of 380 kHz was found for the Barium Titanate sample, and Dual AC Resonance Tracking was used in order to measure the hysteresis for the sample's amplitude and phase. With the applied bias voltage, the Barium Titanate sample experienced hysteresis caused by the piezoelectric effect between -4 and 4 Volts.