Incorporation of Monovalent Ions in ZnO and Their Influence on Varistor Degradation

An atomistic simulation technique has been used to predict the spatial arrangement of the dopant species sodium, lithium, and chlorine within the zinc oxide lattice. The alkaline oxides are preferentially incorporated via a self‐compensating mode, forming interstitial cations which hinder the migration of zinc interstitials and hence slow the degradation of the varistor. The addition of chloride ions is shown to negate this effect by forming sodium and chloride substitutional defects rather than any species involving sodium interstitial ions.