  Phase transformations ruled by non-simultaneous nucleation and growth do not
lead to random distribution of nuclei. Since nucleation is only allowed in the
untransformed portion of space, positions of nuclei are correlated. In this
article an analytical approach is presented for computing pair-correlation
function of nuclei in progressive nucleation. This quantity is further employed
for characterizing the spatial distribution of nuclei through the nearest
neighbor distribution function. The modeling is developed for nucleation in 2D
space with power growth law and it is applied to describe electrochemical
nucleation where correlation effects are significant. Comparison with both
computer simulations and experimental data lends support to the model which
gives insights into the transition from Poissonian to correlated nearest
neighbor probability density.
