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Characterization of nanostructured materials using SEM and HREM techniques
Author(s) -
Perez R.,
Gomez J.
Publication year - 1998
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/(sici)1097-0029(19980101)40:1<10::aid-jemt3>3.0.co;2-0
Subject(s) - materials science , characterization (materials science) , transmission electron microscopy , crystallite , scanning electron microscope , grain boundary , nanometre , alloy , nanostructure , nanotechnology , microstructure , crystallography , composite material , metallurgy , chemistry
A microstructural characterization based on analytical scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HREM) was carried out on nanostructured M50‐type steel and also on nanometer‐sized gold particles. Both nanostructured materials were prepared with different chemical methods recently reported in the literature. The obtained nanostructured steel powders were subsequently consolidated into bulk samples. The SEM studies of the M50 compound probes show the presence of pores of different sizes. The composition of the specimens indicates small differences with the M50‐type steel alloy, with strong variations of the vanadium amount in the cavities of the compound. The HREM images show the presence of small precipitates in the range of a few nanometers in size. The structural characteristics of the grain boundaries between the nanometric crystallites were also explored. The geometrical relationships between adjacent α‐Fe grains were obtained for some particular boundary arrangements. The nanometric gold particles show diameters which vary from 4 to 11 nm. Some of these particles display twin boundary arrangements. The nature of these twin arrangements was also explored. Theoretical simulations based on the multislice theory of the electron diffraction dynamical theory were carried out mainly to explore the nature of the twin boundaries obtained in the gold particles. Comparisons between the simulated images and the experimental results are presented. Microsc. Res. Tech. 40:10–21, 1998. © 1998 Wiley‐Liss, Inc.