Practical spatial resolution of electron energy loss spectroscopy in aberration corrected scanning transmission elecron microscopy.
- Center for Nanoscale Materials
The resolution of electron energy loss spectroscopy (EELS) is limited by delocalization of inelastic electron scattering rather than probe size in an aberration corrected scanning transmission electron microscope (STEM). In this study, we present an experimental quantification of EELS spatial resolution using chemically modulated 2 x (LaMnO{sub 3})/2 x (SrTiO{sub 3}) and 2 x (SrVO{sub 3})/2 x (SrTiO{sub 3}) superlattices by measuring the full width at half maxima (FWHM) of integrated Ti M{sub 2,3}, Ti L{sub 2,3}, V L{sub 2,3}, Mn L{sub 2,3}, La N{sub 4,5}, La N{sub 2,3} La M{sub 4,5} and Sr L{sub 3} edges over the superlattices. The EELS signals recorded using large collection angles are peaked at atomic columns. The FWHM of the EELS profile, obtained by curve-fitting, reveals a systematic trend with the energy loss for the Ti, V, and Mn edges. However, the experimental FWHM of the Sr and La edges deviates significantly from the observed experimental tendency. Spatial resolution of aberration corrected STEM/EELS measured for Ti M{sub 2,3}, Ti L{sub 2,3}, V L{sub 2,3}, Mn L{sub 2,3}, La N{sub 4,5}, La N{sub 2,3} La M{sub 4,5} and Sr L{sub 3} edges using oxide superlattices. EELS signals recorded using large collection angles are peaked at atomic columns. The FWHM of the EELS profiles agrees with Egerton's empirical delocalization model for Ti, V, and Mn edges in thin samples. The FWHM of the Sr and La edges is larger than the model's prediction because of scattering by heavy atomic columns.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- SC
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1018192
- Report Number(s):
- ANL/MSD/JA-69656
- Journal Information:
- Micron, Journal Name: Micron Journal Issue: 6 ; Aug. 2011 Vol. 42; ISSN 0968-4328
- Country of Publication:
- United States
- Language:
- ENGLISH