  We propose the thermodynamical theory of nanodomain tailoring with the help
of atomic force microscope electric field in thin ferroelectric-semiconductor
films. We modified the existing thermodynamical models of domain formation
allowing for the Debye screening, recharging of sluggish surface charge layers
caused by emission current between the tip apex and sample surface.For the
first time we calculated the realistic sizes of nanodomains recorded in BaTiO3,
PbZrxTi1-xO3 and LiTaO3 ferroelectric-semiconductor thin films in contrast to
the over-estimated ones obtained in the evolved approaches. We have shown that
the depolarization field energy of the domain butt, Debye screening effects and
field emission at high voltages lead to the essential decrease of the
equilibrium domain sizes. For the first time we obtained, that the domain
radius does not decrease continuously with applied voltage decrease: the domain
appears with non-zero radius at definite critical voltage applied to the tip.
This result completely agrees with experimentally observed threshold domain
recording in PbZrxTi1-xO3 and LiTaO3 thin films. Such threshold domain
formation is similar to the first order phase transition. We hope, that our
results will help one to determine the necessary recording conditions and
appropriate ferroelectric medium in order to obtain the stable domains with
minimum lateral size in a wide range of applied voltages.
