O− detected by ESR as a radiation-induced electron-excess defect in KClO3

Abstract

A family of ESR spectra from KClO₃ crystals irradiated with x rays at 26 K are assigned to electron‐excess defects consisting of O⁻ ions trapped in different environments, which may be identified because the electron spin on O⁻ polarizes the adjacent ions. In the primary configurations, O⁻ is associated with ClO⁻₂. Secondary configurations, in which O⁻ is trapped between two ClO⁻₃ ions, arise from a thermally activated substitution process of the Grotthuss type: leading to migration of the excess negative charge along the crystallographic axis a. The O⁻ defects in KClO₃ are structurally very similar to those observed earlier in irradiated KClO₄. As in KClO₄, O⁻ reacts with O₂ at ∼230 K to yield O⁻₃.