抄録
New type defects on {111} planes have been observed in quenched pure aluminum with a transmission electron microscope. The new type defect has the shape of a double loop with edges parallel to ⟨110⟩ directions, and its outer loop is hexagonal in shape and its inner loop triangular. From their image contrast, their shape and their annealing behavior, the double loop can be understood to be constructed of two overlapping Frank sessile loops on successive atomic planes. The nature of double loop suggests that the interaction energy of stacking faults, one atomic plane apart, is fairly large.
