Defect Interactions and Their Effect upon the Intrinsic Defect Concentrations for AgCl

Abstract

The effect of defect interactions upon the equilibrium concentration of intrinsic Frenkel defects in the silver halides was investigated employing the formalism developed by Allnatt and Cohen. Using the value of the Frenkel pair free formation energy obtained by Abbink and Martin, the intrinsic defect concentrations were calculated for temperatures between 400°K and the melting temperature. It was found that the results using this theory were in reasonable agreement with results obtained from the well‐known Debye–Hückel‐type theory of Lidiard for temperatures below ∼620°K, significant differences appearing above this temperature. Defect concentrations were also evaluated using the free formation energy determined by Müller. In all calculations, significant effects were associated with the temperature dependence of the dielectric constant.