ELLE Nucleation Examples
Below, we provide example models and movies, with accompanying explanations. Click on the images to play movies.
The image at left is frame 20 of an 80-frame movie that shows nucleation and growth of a new (red) phase. This movie more or less follows the code documented in the previous section. The code searches for triple nodes, and when it finds a triple note it investigates the surrounding grains. If at least one of the surrounding grains is a dark blue phase ("mica") then it turns that node into a new grain (the red phase). Note that the red phase continues to grow after nucleating, and the rate of this growth is controlled by the expand code. This is part of an investigation into porphyroblast nucleation and growth in pelitic layers of a turbidite sequence.
The image at left is frame 30 of a 98-frame movie that shows nucleation and growth of of a new phase. The new phases look like multi-color bird tracks. This is actually a grain boundary diffusion map around each new grain, the new grains being too small to see at this scale. In the example, the code searches for triple nodes in a very fine microstructure, and when it finds a triple note it investigates the local grain boundary chemical concentrations. If it is not too close to a previously nucleated grain, than a nucleus is formed. This is part of an investigation into the control of diffusion rates on the spacing of nuclei.
The image at left is frame 20 of an 51-frame movie that shows nucleation and growth of a new (pink) phase in a pelitic layer during deformation. This movie more or less follows the code documented in the previous section. The code searches for triple nodes, and when it finds a triple note it investigates the surrounding grains. If at least one of the surrounding grains is a dark blue phase ("mica") then it turns that node into a new grain (the pink phase). Note that the pink phase continues to grow after nucleating, and the rate of this growth is controlled by the expand code. This is part of an investigation into porphyroblast nucleation and growth in pelitic layers of a turbidite sequence, and the effects of new phases on the relative viscosities of layers during metamorphism and deformation.