Here are $2$ graphics $($ A and $B)$ indicating the crystal growth of $2$

precipitates. The chemical composition of the precipitate is

different from the composition of the matrix. One represents

"diffusion$-$controlled" growth and the other represents

"interface controlled" growth. Which is which? Explain your

answer noting the profiles you see in these graphics.

Another way of viewing these graphics is to say that one

mechanism dominates for small particles where diffusion

distances are small and the other mechanism dominates for large

particles where there is depletion of the solute. Which is

which? Explain your answer noting the profiles you see in these

graphics.