Brice Gautier

Abstract:

Assessing ferroelectricity in thin films or single crystals is of crucial importance whenever these materials are to be integrated in electronic devices for applications to e.g. memories, low consumption transistors or sensors. For all these applications, it has become mandatory to measure ferroelectricity at the nanoscale. One of the most popular tools to do so is Piezoresponse Force Microscopy (PFM) which is derived from Atomic force Microscopy (AFM), and allows to map ferroelectric domains, to obtain hysteresis loops at the nanoscale as well as to write domains by the application of voltages between the tip and the sample. We describe in this communication the capabilities of such a technique. But since several years, PFM has lead to severe misinterpretations because some non-ferroelectric layers have lead to perfect PFM images and loops. We will explain the origins of these misinterpretatations and propose an alternative method based on current measurements (nano-PUND), which seems to be more powerful and less sensitive to artefacts than PFM when ferroelectricity has to be assessed.