Color Center Formation by Pulse Irradiation of Alkali Halides

✍ Scribed by J. H. Schulman; J. W. Boag

• Publisher: John Wiley and Sons
• Year: 1963
• Tongue: English
• Weight: 440 KB
• Volume: 3
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.19630030315

✦ Synopsis

Abstract

Preliminary observation is made of the absorption spectra of four alkali halides (LiF, NaCl, KCl, and KBr) at various intervals after bombardment, at room temperature, with a 2 microsecond pulse of 2 MeV electrons. The absorption is measured spectrographically using an underwater uranium spark light source which can be triggered either “simultanously” with the electron beam or after a predetermined delay of a few microseconds or longer. In addition to the expected intense and persistent F‐bands, transient absorption bands in the ultraviolet are observed in all cases, some with lifetimes of the order of a few tens of microseconds at room temperature, and others which persist along with the F‐band. These transient bands appear to be due to trapped‐hole centres such as the V~K‐~, H‐, or V~1~‐centres, which previously have been observed only at low temperatures.