(a) for the solidification of iron, calculate the critical radius r* and the activation free energy δg* if nucleation is homogeneous. values for the latent heat of fusion and surface free energy are –1.85 × 109 j/m3 and 0.204 j/m2, respectively. use the supercooling value δt = 274 k, and the melting point of iron is 1538°c. critical radius, r* = nm activation free energy δg* = j
(b) now calculate the number of atoms found in a nucleus of critical size. assume a lattice parameter of 0.292 nm for solid iron at its melting temperature. number of atoms for critical size = atoms/critical nucleus