Probing non-dipole allowed excitations in highly correlated materials with nanoscale resolution

Alexandre Gloter; Ming-Wen Chu; Mathieu Kociak; Cheng Hsuan Chen; Christian Colliex

doi:10.1016/j.ultramic.2009.06.005

Probing non-dipole allowed excitations in highly correlated materials with nanoscale resolution

Ultramicroscopy. 2009 Oct;109(11):1333-7. doi: 10.1016/j.ultramic.2009.06.005. Epub 2009 Jun 18.

Authors

Alexandre Gloter¹, Ming-Wen Chu, Mathieu Kociak, Cheng Hsuan Chen, Christian Colliex

Affiliation

¹ Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris Sud, F-91405 Orsay, France. gloter@lps.u-psud.fr

PMID: 19573991
DOI: 10.1016/j.ultramic.2009.06.005

Abstract

Here, we demonstrate that non-dipole allowed d-d excitations in NiO can be measured by electron energy loss spectroscopy (EELS) in transmission electron microscopes (TEM). Strong excitations from (3)A(2g) ground states to (3)T(1g) excited states are measured at 1.7 and 3 eV when transferred momentum are beyond 1.5 A(-1). We show that these d-d excitations can be collected with a nanometrical resolution in a dedicated scanning transmission electron microscope (STEM) by setting a good compromise between the convergence angle of the electron probe and the collected transferred momentum. This work opens new possibilities for the study of strongly correlated materials on a nanoscale.

Publication types

Research Support, Non-U.S. Gov't