High Resolution Imaging of As-Grown Sapphire Surfaces

1985 ◽  
Vol 62 ◽  
Author(s):  
Tung Hsu ◽  
S. R. Nutt

ABSTRACTSurfaces of commercially grown edge-defined film-fed growth sapphire (EFG α-Al2O3) were studied in the electron microscope using both reflection electron microscopy (REM) and conventional transmission electron microscopy (TEM). The as-grown sapphire surface, ostensibly {1120}, was characterized by “rooftop” structures which were often locally periodic. These rooftop structures consisted of alternating {1120} facets and additional facets inclined a few degrees. The crystallography of the surface facets was analyzed using REM imaging of bulk specimens, and trace analysis of back-thinned plan section TEM specimens. Surface roughness was measured by stylus profilometry. and these measurements were compared to the electron microscopy observations. Fine structural features parallel to <0110> directions were also observed in both REM and TEM experiments, and these were attributed to surface steps of atomic scales.

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1304 ◽  
Author(s):  
Giulio Guzzinati ◽  
Thomas Altantzis ◽  
Maria Batuk ◽  
Annick De Backer ◽  
Gunnar Lumbeeck ◽  
...  

The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science.


1996 ◽  
Vol 11 (11) ◽  
pp. 2777-2784 ◽  
Author(s):  
S. Takeno ◽  
S. Nakamura ◽  
K. Abe ◽  
S. Komatsu

A novel mosaic-like structure in SrTiO3 thin films was discovered and characterized by means of transmission electron microscopy (TEM). The films were deposited on a (001) oriented Pt surface. The orientation relationship between SrTiO3 film and Pt substrate was determined, and four types of growth modes were revealed. These four growth modes formed four types of domains, respectively, and these domains and Pt formed peculiarly ordered interfacial structures, i.e., near coincidence site lattices. Antiphase boundaries between two adjacent domains were also observed by high-resolution imaging.


Author(s):  
J. Bihr ◽  
G. Benner ◽  
D. Krahl ◽  
A. Rilk ◽  
E. Weimer

Conventional transmission electron microscopy (CTEM) can be used for high resolution imaging of specimens and for the analysis of minute specimen areas. The capabilities of such an instrument are strongly improved by the integration of an imaging electron energy loss spectrometer. All imaging and diffraction techmques are provided in such an energy filtered transmission electron microscope (EFTEM).In addition to the well-known objective lens for Koehler illumination, the new Zeiss EFTEM features a projective lens system which integrates a new imaging ω-spectrometer comprising four individual magnets and one hexapole corrector Fig.l and Fig. 3 show the design of this microscope.


1983 ◽  
Vol 31 ◽  
Author(s):  
Pierre M. Petroff

ABSTRACTSurface sensitive transmission electron microscopy (SSTEM) and reflection electron microscopy (REM) have been used to analyze the Si (111) 1×1 → 7×7 surface reconstruction. The SSTEM and transmission electron diffraction results for the Si (111) 7×7 surface are interpreted using several possible “surface dislocation” models. The SSTEM and REM techniques have also been applied to the GaAs (100) MBE deposited surfaces. The rough surface topography for the c(4×4) reconstructed surface is attributed to surface steps motions and bunching upon interruption of the MBE deposition.


1989 ◽  
Vol 159 ◽  
Author(s):  
Jane G. Zhu ◽  
Stuart McKeman ◽  
Chris J. Palmstrøm ◽  
C. Barry Carter

ABSTRACTCoGa/GaAs and ErAs/GaAs grown by molecular-beam epitaxy have been studied using high-resolution transmission electron microscopy (HRTEM). The epitactic interfaces have been shown to be abrupt on the atomic scale. Computer simulations of the HRTEM images have been obtained for different interface structures under various specimen and image conditions. Practical problems in the comparison between the simulated and experimental images are discussed.


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