HOW TO EXTRACT SPONTANEOUS POLARIZATION INFORMATION FROM EXPERIMENTAL-DATA IN ELECTRIC FORCE MICROSCOPY

To derive the spontaneous polarization of a sample, the first harmonic signal of the electric force microscope (EFM) must be corrected using the permittivity. This can be deduced from a simple EFM-force model a nd has been verified in experiments. For thin films of high permittivi ty, any gap of air between the tip and the sample prevents the accurat e measurement of the permittivity. Therefore, the contact mode of EFM has to be chosen for measurements of the spontaneous polarization of s uch films. (C) 1998 Elsevier Science B.V. All rights reserved.