A pulse radiolysis study of electron tunneling in an 8 M NaOH glass between 4 and 100 K

Abstract

Pulse radiolysis experiments have been performed in an 8 M NaOH glass between 4 and 100 K and in the time range 10−6 to 10 s. The spur radius was estimated from the decay of the trapped electrons on the red side of the absorption maximum. The spur radius was about 4 nm at 80 K and increased to about 6 nm at 10 K. We studied the decay of trapped electrons in the presence of the following electron scavengers: CrO2−4, Fe(CN)3−6, and NO−2. No temperature dependence was found between 10 and 100 K. To explain the results distance-dependent and/or time-dependent Franck–Condon factors have been introduced. We show that in the time range studied it is not possible to distinguish between direct tunneling and trap-to-trap tunneling. Dry electron scavenging efficiencies and encounter pair formation are expressed in S37. For CrO2−4, Fe(CN)3−6, and NO−2 we found that S37 was 45, 130, and 300 M, respectively.