An overview of the historical development of positron spectroscopy as a probe of condensed matter on the atomic and nano‐scale is followed by an introduction to the fundamentals of positron annihilation and interactions with condensed matter.
The experimental techniques of positron lifetime and Doppler broadening spectroscopies, angular correlation of annihilation radiation, and their derivatives, are presented. The development of positron beams of controllable energy for the study of surfaces, interfaces and thin films and layers is described.
Finally, examples are given which illustrate how the application of positron annihilation spectroscopy to probe the electronic structure of materials–in the bulk or at or near the surface–yields information not only of a fundamental nature, but also on technologically‐important structural, chemical and electronic properties such as open‐volume defects, nano‐structures, free volumes and phase changes.