Atomic-scale observation of polarization switching in epitaxial ferroelectric thin films

摘要

The thin-film x-ray standing wave (XSW) technique is used for an atomic-scale study of polarization switching in ferroelectric Pb(Zr_(0.3)Ti_(0.7))O_(3) (PZT)/electrode heterostructures grown on SrTiO_(3)(001). The XSW is selectively generated in the PZT by the interference between the incident x-ray wave and the weak (001) Bragg diffracted wave from the film. The XSW excites a fluorescence signal from the Pb ions in the PZT film, that is used to determine their subangstrom displacements after polarization switching has occurred. This experimental method yields unique information on the underlying atomic configurations for different polarization domain states.