The role of reduced dimensionality and the structure of interfaces, point and planar defects, dislocations, etc, remains obscure in many cases but are central to macroscopic materials properties. Imaging interfaces and defects at sub-Angstrom resolution, and chemical mapping at atomic level are some of the hot points to be addressed in materials science.

We concentrate on establishing relations between the structure, chemistry and physical properties of transition-metal oxide nanostructures by means of scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). The recent successful correction of aberrations in electron optics allows us accessing the structure and chemistry of low dimensional materials due to its unparalleled spatial resolution, and combined with monochromated EELS it has the potential to probe optical excitations—plasmons, photons, excitons— with sub-nanometer resolution. This gives unprecedented power to understand the ultimate origin of the properties of materials at the nanoscale.