  The chemical pathways leading to gamma-prime(L1_2)-nucleation from nondilute
Ni-5.2 Al-14.2 Cr at.%, gamma(f.c.c.), at 873 K are followed with radial
distribution functions and isoconcentration surface analyses of direct-space
atom-probe tomographic images. Although Cr atoms initially are randomly
distributed, a distribution of congruent Ni3Al short-range order domains (SRO),
<R> =0.6 nm, results from Al diffusion during quenching. Domain site occupancy
develops as their number density increases leading to Al-rich phase separation
by gamma-prime-nucleation, <R>=0.75 nm, after SRO occurs.
