Ductile-brittle transition in micropillar compression of GaAs at room temperature

Experiments have been carried out on how compressive failure of < 100 > axis GaAs micropillars at room temperature is influenced by their diameter. Slip was observed in all micropillars, often on intersecting slip planes. Cracks could nucleate at these intersections and then grow axially in the sample, with bursts of crack growth. However, GaAs micropillars with diameters less than approximately 1 mu m did not split, nor was splitting observed where slip occurred on only one plane. The conditions under which such splitting can occur have been estimated by modifying an existing analysis. This predicts a ductile-brittle transition at a micropillar diameter of approximately 1 mu m, consistent with experimental observations.