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Gamma-Induced Electrical Conductivity in Alumina

1966; Taylor & Francis; Volume: 25; Issue: 3 Linguagem: Inglês

10.13182/nse66-a17828

1943-748X

G.J. Dau, Monte V. Davis,

Advanced ceramic materials synthesis

Theoretical development for the gamma-induced production of conduction band electrons in alumina is presented. Consideration of charge carrier mobility limited investigations to crystals having ionic bonding. Because of the difficulty in evaluating theoretical constants, all were combined and considered to be independent of temperature and radiation. This constant was evaluated experimentally. A model with a single trap depth was developed for predicting conductivity of ionic insulators as a function of temperature and radiation dose rate. The model is where the first term on the right represents ionic conductivity of material external to a radiation field and the second term describes radiation-induced conductivity. Term P represents gamma dose rate in roentgen per hour, G is an experimentally determined constant, and W represents the energy necessary to raise trapped electrons into the conduction band. The temperature dependence of the mobility is represented by (T)3/2. Evaluation of experimental data for alumina gave W = 0.086 ± 0.014 eV and G = 7.4 × lO−21 (Ω−1cm−1K3/2R−1h).