A diffusion model for solute atoms diffusing and aggregating in nuclear structural materials
Song Quan1, 2, Meng Fan-Xin3, Ning Bo-Yuan4, Zhuang Jun4, Ning Xi-Jing1, 2, †
       

(color online) Schematic diagrams of bulk materials composed of (a) crystal grains and (b) defects (circles) in a crystal grain. For simplicity, a defect is considered to be a small ball of radius r0 located in the center of a big ball of radius R, in which there may exist solute atoms (c).