Temperature dependence of polarization and charge dynamics on the BaTiO3(100) surface by scanning probe microscopy

Variable-temperature atomic force microscopy, piezoresponse force microscop y (PFM), and scanning surface potential microscopy were combined to determi ne the temperature response of polarization and screening charge on BaTiO3( 100) surfaces. The ferroelectric-domain induced surface corrugations and pi ezoelectric response decrease with temperature and disappear at the Curie t emperature. The temperature dependence of the PFM contrast is explained wit hin the framework of the Ginzburg-Devonshire theory with the effect of a di electric tip-surface gap taken into account. The temperature dependence of the surface potential contrast is ascribed to the interplay between the rel ease of the screening charges with temperature and their slow relaxation. T he results indicate that surface potential polarity is reversed relative to that expected from polarization orientation on BaTiO3 in ambient. (C) 2001 American Institute of Physics.