Skip to main content
Microscopy

Microscopy

Positrons go into detail

05 Nov 2001

New measurements of the lifetimes of positrons herald the next generation of positron microscopes – complex relatives of the electron microscope that identify defects in surfaces.

Over the last 50 years, a number of techniques have been developed to analyse surfaces, near-surface layers and interfaces. Each technique has its own peculiar characteristics, and offers a different view of surface phenomena. Positron-annihilation spectroscopy has unique capabilities for detecting vacancy-like defects, ranging from individual missing atoms to micro-voids.

Over the last 20 years, positrons have increasingly been used as a tool for investigating solids in the lab. The entire field has progressed enormously in the last 10 years, in particular with regard to the extraction of information for industrial use. Now Gottfried Kögel’s group at Bundeswehr University in Munich, Germany, has reported the first lifetime measurements with a scanning positron microscope (A David et al. 2001 Phys. Rev. Lett. 87 67402).

In the November issue of Physics World, Antonio Zecca and Grzegorz Karwasz of the University of Trento, Italy, describe the development of the positron microscope, which is a much more complex instrument than an electron microscope.

Copyright © 2024 by IOP Publishing Ltd and individual contributors