Scanning probe microscopy investigation of ferroelectric properties of barium strontium niobate crystals

The ferroelectric properties of relaxor ferroelectric materials Sr (x) Ba1 - x Nb2O6 of different compositions have been investigated using scanning probe microscopy and macroscopic polarization methods. An analysis of the results obtained from microscopic and macroscopic measurements of the hysteresis loops has demonstrated that a frequency dependence of the coercive field E (c) is observed at frequencies f in the range from 0.03 to 250 Hz, so that the coercive field E (c) regularly decreases with decreasing frequency. The observation of the kinetics of domains under a direct-current voltage applied to the probe of the atomic force microscope has revealed a lateral motion of domain walls in response to electric fields E a parts per thousand(a) E (c) . This result qualitatively explains a slow polarization relaxation occurring for a giant time in Sr (x) Ba1 - x Nb2O6.