Characterization of JEOL 2100F Lorentz-TEM for low-magnification electron holography and magnetic imaging.
Ultramicroscopy
; 108(7): 625-34, 2008 Jun.
Article
em En
| MEDLINE
| ID: mdl-18328628
ABSTRACT
We present results that characterize the performance and capabilities of the JEOL 2100F-LM electron microscope to carry out holography and quantitative magnetic imaging. We find the microscope is well-suited for studies of magnetic materials, or for semi-conductor dopant profiling, where a large hologram width ( approximately 1 microm) and fine fringe spacing ( approximately 1.5 nm) are obtained with good contrast ( approximately 20%). We present, as well, measurements of the spherical aberration coefficient Cs=(108.7+/-9.6)mm and minimum achievable focal step delta f=(87.6+/-1.4)nm for the specially designed long-focal-length objective lens of this microscope. Further, we detail experiments to accurately measure the optical parameters of the imaging system typical of conventional holography setup in a transmission electron microscope. The role played by astigmatic illumination in the hologram formation is also assessed with a wave-optical model, which we present and discuss. The measurements obtained for our microscope are used to simulate realistic holograms, which we compare directly to experimental holograms finding good agreement. These results indicate the usefulness of measuring these optical parameters to guide the optimization of the experimental setup for a given microscope, and to provide an additional degree of practical experimental possibility.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Holografia
/
Microscopia Eletrônica de Transmissão
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Ultramicroscopy
Ano de publicação:
2008
Tipo de documento:
Article