Electrical characterization of perovskite nanostructures by SPM

Abstract

Electrical measurements on perovskite materials were reported as early as 1930 by [1]. Since that time research has changed its focus from bulk ceramic and single crystals to thick and thin films. Within this trend to nanotechnology, the characterization techniques have changed to investigate the nanosized material properties. From the various methods that exist to characterize electrically perovskite materials, we concentrate in this chapter on the local electrical measurements of ferroelectric hysteresis, small signal capacitance, and local conductivity distributions. In these methods an atomic force microscope (AFM) tip is brought into contact with a nanosized top electrode or with the surface of the sample. Table 1 describes the interplay between the requirements for characterization on the nanoscale and the measurement limitations imposed by the setup or the recording system for different sample configurations and characterization methods. Exploring nanosized properties ranging over many orders of magnitude poses high demands on the measuring equipment. Current values from femto-to microamperes, deformations from pico-to micrometers, and potentials from hundreds of volts down to microvolts have to be measured. In order to investigate these properties, a thorough understanding of the measuring equipment is vital. Therefore, the principal setup of the measuring systems used is presented and their possibilities and drawbacks are discussed. Reliable results on small structures can only be obtained if parasitic effects are taken into account. In this chapter, we show ferroelectric as well as dielectric measurements on small capacitors. © 2007 Springer Science+Business Media, LLC.