Clustering of small defects in non-stoichiometric rutile

Abstract

A simple electrostatic model for the effective charges associated with small linear defects in non-stoichiometric mile is introduced. This is used to predict relative stabilities of clusters of linear defects. The results are in good agreement with recent high-resolution electron microscopic observations of the presence of small cluster defects in non-stoichiometric rutile (TiO_2-x; 0≤x≤0·0035) and chromia-doped rutile ((Ti, Cr)O_2-x; 0≤x≤0·05), and with observations of the precipitation of pairs of crystallographic shear planes and {100} platelet defects.