SCANNING FORCE MICROSCOPY OF DOMAIN-STRUCTURE IN FERROELECTRIC THIN-FILMS - IMAGING AND CONTROL

Scanning force microscopy (SFM) has been used to perform nanoscale stu dies of domain structures and switching behaviour of Pb(ZrxTi1-x)O-3 ( PZT) thin films. An SFM piezoresponse mode, based on the detection of the piezoelectric vibration of a ferroelectric sample, was shown to be suitable for high resolution imaging of ferroelectric domains in thin films. The lower limit of the piezoresponse mode imaging resolution d epends on the radius of the probing lip and is estimated to be of the order of several nanometers. The effect of the film microstructure on the imaging resolution is discussed. The ability of effective control of domains as small as 50 nm by means of SFM has been demonstrated. Ii : is shown that SFM can be used in the investigation of electrical deg radation effects in ferroelectric thin films. Formation of regions wit h unswitchable polarization as a result of fatigue, within grains of s ubmicron size, was experimentally observed.