Sub-boundaries on (002) cleavages of Li2CO3 single crystals

Linear arrays of dislocations (straight, terminating and curved) are observed on etching with 2% citric acid (002) cleavages of lithium carbonate (Li₂CO₃) single crystals, grown by zone melting technique. As the dislocations are non-uniformly spaced and disappear on successive etching, they may not be revealing low-angle grain boundary, nor slip traces as they are terminating and curved meaning crystallographically non-oriented. On the observation of experiments on successive etching and etching of matched pairs, it is concluded that the arrays of etch pits reveal dislocation walls (dislocation density 1.1 × 10⁶ — 1.5 × 10⁷ pits cm⁻²) probably created due to the localized thermal stresses released as a result of high temperature annealing of the crystal during growth. The implications are discussed.