The main aim of this proposal is to pave the way to faster, cleaner technologies by boosting our understanding of how local electric fields work at the atomic scale in functional materials. During the last decade, the scientific community has addressed this task by developing advanced microscopy techniques sensitive to local physical quantities such as the electrostatic potential around atoms. POLAR-EM has produced a software tool to support the fast and reliable application of such techniques and allow routine, inexpensive atomic resolution mapping of such electrostatic potentials and fields within materials in the electron microscope. Such mapping capabilities could revolutionize our understanding of future materials for devices based on exploiting functionalities such as ferroelectric polarization. This application will be of fundamental interest to researchers and engineers in both academia and industry working in fields such as nanodevices including elements with ferroelectric components, technologies that are already present in the market but need to be improved. In fact, the key to the realization of future non-volatile electronic devices based on ferroelectrics relies on the availability of probes that can study materials and their electric properties in an atom-by-atom fashion. Imaging techniques directly sensitive to the local electrostatic potential (i.e. the local electrostatic field associated with the presence of polarization) constitute a must-have tool to materials researchers and engineers worldwide, and this is the niche that POLAR-EM has aimed to fill.
We have produced a software application that can be implemented within commercial electron microscope control platforms, capable of both acquiring and processing the electron diffraction images that constitute the basis of the current approach to atomic resolution electric field mapping. Our app is routinely capable, in a straightforward manner, of:
1) Setting up the measurement conditions and acquire multidimensional diffractive imaging data sets with atomic resolution on the desired samples.
2) Image selectively via post-acquisition processing and perform relatively simple operations such as Fourier transform or partial integration to produce DPC images.
3) Help with the interpretation of the resulting images in order to retrieve the electrostatic potential, fields or other physical quantities (such as the wavefunction phase), as needed.
Our technology is thus capable of acquiring and processing multidimensional electron diffraction data in the electron microscope. It may run as a stand-alone tool or become a part (plug-in) of currently existing commercial electron microscopes control software via a user-friendly interface that can be made available to R&D departments in both academia and industry. The resulting reliable mapping of fields and local polarization in materials will pave the way that will lead the academia-industry tandem from atomistic phenomena to actual, low-power fast read-write devices based on ferroelectrics.
