It was recalled that it had been proposed that a [001] interstitial-type dislocation loop could be formed in body-centered cubic iron via a collision between a ½[111] loop and a ½[111] loop which underwent one-dimensional glide diffusion, and a subsequent shear reaction. However, the formation of [001] loops via this reaction had not been reproduced even when two ½<111> loops collided with each other. Here, the origin of the difficulty of this reaction was considered within the framework of isotropic elasticity theory. The sign of the driving force for the reaction was heavily dependent upon the reaction path. The two ½<111> loops which collided to form a [110] junction could transform into a single [001] loop when a shear loop, generated within the ½[111] loop, propagated in concert with the other shear loop within the ½[111] loop. However, unconcerted motion of the 2 shear loops significantly suppressed the propagation of the shear loops, which could be caused by thermal fluctuations at finite temperatures. This was one of the origins of the difficulty of the formation of [001] loops via a collision between two ½<111> loops.

Energetics of Formation Process of a <001> Prismatic Dislocation Loop via the Collision between Two 1/2<111> Loops in α-Iron. K.Arakawa, H.Mori: Journal of Physics - Conference Series, 2009, 165[1], 012005 (4pp)