38426
Accession Number
24593
Editor
Olsen, Sandra L.
Title Of Article Chaper
Backscattered electron imaging of archaeological material
Title Of Journal Book
Scanning electron microscopy in archaeology
Pages
23-44
Collation
24 figs.
Reference Bibliography
Includes 9 bibliog. refs.
Publisher
British Archaeological Reports
Publisher City
Oxford
ISBN
0 86054 579 2
Language Of Text
English
Literature Type
Monograph
Literature Level
Analytic
Meeting
Scanning Electron Microscopy in Archaeology
Abstract
Backscattered electron (BSE) imaging in the scanning electron microscope has gained stature in recent years because of the availability of more efficient detectors that can exploit the compositional or atomic number contrast between closely similar phases in polished samples. The compositional contrast increases and clarifies the information available from a sample and therefore speeds interpretation, as well as deepening the knowledge obtained from examining the material. An additional benefit of BSE is the suppression of specimen charging in the SEM that occurs with secondary electron images, for example on the surface of antiquities due to corrosion and burial debris, and on samples that are difficult to vacuum coat, but charging is generally absent in BSE images. Topographic information is also of importance in the BSE signal coming from the specimen. However, the type of image obtained, whether compositional, topographic or mixed depends not only on the prepared condition of the sample (eg polished, etched, fractured, etc. ), but also on the choice of SEM accelerating voltage and probe current, which can be particularly important for ceramic materials. The detector/specimen geometry also has an important effect on the type of image as does the size and design of the BSE detector to some extent. Therefore, detectors mounted with different geometries and working distances give images with different contributions of compositional and topographic contrasts. Edge bright-up effects may also be enhanced or suppressed. The purpose of this paper is to illustrate what has been found to be the best BSE imaging conditions for a variety of archaeological materials.
Keywords
backscatter;electron;image;archaeology;SEM;scanning electron microscope -- CAL
pub_id
38426