  The boundary conditions, customarily used in the Landau-type approach to
ferroelectric thin films and nanostructures, have to be modified to take into
account that a surface of a ferroelectric (FE) is a defect of the ``field''
type. The surface (interface) field is coupled to a normal component of
polarization and, as a result, the second order phase transitions are generally
suppressed and anomalies in response are washed out. In FE films with a
compositional (grading) or some other type of inhomogeneity, the transition
into a monodomain state is suppressed, but a transition with formation of a
domain structure may occur.
