Today's high-tech applications require characterization methods which are able to measure material properties on the nanometre scale. Recently, to the need has emerged to measure the intrinsic magnetic and electric fields in nanometre-sized patterned materials. This includes the emerging field of spintronics, where it is important to determine the micromagnetic state of sub-µm patterned magnetic materials, and optoelectronics, where quantum wells in non-centrosymmetric materials cause strong piezoelectric fields which modify the band structure of these devices. For successful research in these and related areas, a nanometre-scale characterization of electric and magnetic properties is essential.

Differential phase contrast (DPC) is an emerging technique which allows the visualization of electric and magnetic fields in the vicinity of a sample. We will explain in detail how DPC works in a STEM and give examples for its application in different areas. We address a broad audience and no specialized knowledge will be necessary apart from a basic understanding of STEM.  We will also give some hints and tricks on how a "poor scientist’s" differential phase contrast can be achieved in a regular STEM. We will present some simple but useful formulae and many examples of imaging magnetic and electric fields and explain ways to calibrate the measurements. The examples shown are both on a mesoscopic (µm to nm) and a microscopic (nm to sub-Angstrom) scale. The experiments are performed both on a Tecnai F30ST and a double corrected Titan cubed 80-300.  

You'll learn about:

•    A newly emerging technique in STEM
•    Get answers on your questions about possibilities and pitfalls of the technique
•    Find out if differential phase contrast offers you advantages beyond the techniques you use regularly
•    Experience the fascination of "seeing" electric and magnetic fields