Microscopy and Microanalysis

Table of Contents - 2003 - Volume 9, Issue 01  


Instrumentation and Technique

Enhanced Compositional Contrast in Imaging of Nanoprecipitates Buried in a Defective Crystal Using a Conventional TEM

Ute  Kaiser  a1 c1 and Andrey  Chuvilin  a1 a2
a1 Institut für Festkörperphysik, Friedrich-Schiller Universität, Jena 07743, Germany
a2 Institute of Catalysis, Novosibirsk, 90630090 Russia

Abstract

In this article, we show that nanometer-sized precipitates of atomic numbers higher than those of the surrounding crystalline matrix can be clearly revealed in a conventional transmission electron microscope by high-angle, centered dark-field imaging after minimizing the diffraction contrast. The effect is similar to that of Z-contrast STEM, albeit with a spatial resolution limited to 1 nm. Its sensitivity to atomic number differences between precipitates and matrix is about 10, which is demonstrated for precipitates formed after Er, Ge, Cr, and Si ion implantation into SiC.

(Received February 6 2002)
(Accepted June 6 2002)


Key Words: nanoprecipitates; conventional TEM; diffraction contrast; annular dark-field detector.

Correspondence:
c1 Corresponding author. E-mail: kaiser@pinet.uni-jena.de