Ferroelectric nanostructures

Summary form only given. Scaling down to tens of nanometers or even below is appealing for device miniaturization, on one hand, and for exploring/exploiting novel phenomena arising from nanometer-size effects. Ferroelectric (FE) materials have been proposed for nonvolatile ferroelectric random access memories since two decades (J.F. Scott and C.A.P.D. Araujo, 1989) and lateral dimensions of ca. 100 nm are required for FE dots in order to reach the Gigabit/cm² memory densities. Hence, the fundamental studies of the properties of FE nanostructures and ultrathin films is a prerequisite for device optimization. In the present lecture we will discuss ferroelectric nanostructures generated either by pulsed laser deposition or by other means. The fabrication and properties of two-dimensional superlattice structures of complex oxides as well as of arrays of ferroelectric nanodots and ferroelectric nanotubes will be discussed. We will pay special attention to the fabrication of appropriate templates and masks, which allow lateral nanostructuring. Extensive examples of recent work on ferroelectric nanostructures involving MPI-Halle will be given.