Nucleation and growth in a 2D Ising Model with Monte Carlo Simulation

kd215

I'm currently working on a project for a code that does umbrella sampling of a 2-D Ising model [size LxL of a magnet (analyzing up or down spins)]. The next step is to take my code to analyze a nucleation region and its growth by varying the temperature above critical. Before I even attempt to write more c code, I thought I would ask on this forum to see if I'm interpreting this correctly: (I might sound really stupid with these interpretations, but I have a hard time visualizing this)

I sample the whole magnet and select spin i,j (some position in the lattice). Let's say it's an up spin, analyze its four (nearest) neighbors to see which others are up spins.

Or should I be looking for a region of all up (or down) spins of a predefined size (let's say a square of 3X3, so 9 adjacent spins in the same direction)?

Orrrr should I start with a lattice of entirely all one direction of spins?

And also, even from here I have a hard time understanding the idea of nucleation: so am I trying to compute the energy associated with flipping a down spin that is surrounded by a region of up spins? and the probability/energy associated with spins adjacent that spin also flipping to down?

I have a VERY difficult time understanding and interpreting the ideas of statistical mechanics and analyzing the Ising model so any basic explanations/help would be greatly appreciated!!
Thanks-

cfa1609

Caity, if you need help, just come see me in office hours instead of using physics forums.