  Perceiving nanoscale ferroelectric phenomena from real space is of great
importance for elucidating underlying ferroelectric physics. During the past
decades, nanoscale ferroelectric characterization has mainly relied on the
Piezoresponse Force Microscopy (PFM), however, the fundamental limitations of
PFM have made the nanoscale ferroelectric studies encounter significant
bottlenecks. In this study, a high-resolution non-contact ferroelectric
measurement, named Non-Contact Heterodyne Electrostrain Force Microscopy
(NC-HEsFM), has been introduced firstly. It has been unambiguously demonstrated
that NC-HEsFM can operate on multiple eigenmodes to perform ideal
high-resolution ferroelectric domain mapping, standard ferroelectric hysteresis
loop measurement and controllable domain manipulation. With using quartz tuning
fork (QTF) sensor and heterodyne detection, NC-HEsFM shows an unprecedented
capability in achieving real non-contact yet non-destructive ferroelectric
characterization with negligible electrostatic force effect. It is believed
that NC-HEsFM can be extensively used in various ferroelectric or piezoelectric
studies with providing substantially improved characterization performance.
Meanwhile, the QTF-based force detection makes NC-HEsFM highly compatible for
high-vacuum and low-temperature environments, providing ideal conditions for
achieving an ultra-high spatial resolution to investigate the most intrinsic
ferroelectric phenomena.
