  Piezoresponse Force Microscopy is a powerful but delicate nanoscale technique
that measures the mechanical response resulting from the application of a
highly localized electric field. Though mechanical response is normally due to
piezoelectricity, other physical phenomena, especially electrostatic
interaction, can contribute to the signal read. We address this problematic
through the use of longer ultra-stiff probes providing state of the art
sensitivity, with the lowest electrostatic interaction and avoiding working in
high frequency regime. In order to find this solution we develop a theoretical
description addressing the effects of electrostatic contributions in the total
cantilever vibration and its quantification for different setups. The theory is
subsequently tested in a Periodically Poled Lithium Niobate (PPLN) crystal, a
sample with well-defined 0deg and 180deg domains, using different commercial
available conductive tips. We employ the theoretical description to compare the
electrostatic contribution effects into the total phase recorded. Through
experimental data our description is corroborated for each of the tested
commercially available probes. We propose that a larger probe length can be a
solution to avoid electrostatic forces, so the cantilever-sample electrostatic
interaction is reduced. For hard oxide samples we propose an ultra-stiff
cantilever which avoids the use of high frequency voltage but still diminishing
electrostatic forces. Our proposed commercially available solution have great
implications into avoiding artifacts while studying soft biological samples,
multiferroic oxides, and thin film ferroelectric materials and it opens a new
window into tip engineering.
